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Landscape Basics: Success with Herbaceous Perennials

Bodie Pennisi, Paul Thomas and Sheri Dorn Department of Horticulture

hether in a commercial installation or residen- fewer pest problems, require less water and pruning, Wtial garden, perennial can be successfully and have an extended flowering time. This information used to offer more landscaping choices, distinguish can be acquired from books, annual trade confer- your firm from the competition and create a niche for ences and Extension publications (refer to “Additional your landscape business. Perennial plants are complex, Resources” at the end of this publication). An excellent and it is best to contract or hire a professional land- way to see how new selections perform is to visit the scape architect for the design phase and train knowl- University of Georgia Trial Gardens located on campus edgeable staff in proper maintenance later on. in Athens (http://ugatrial.hort.uga.edu/).

With a rich history of introductions, hybridiza- This publication is intended to provide the basics of tion and selection, we can now enjoy plants in Georgia perennial plant biology, ideas on design and installa- that until recently were once found only on a remote tion, and information on cultivation and maintenance mountain slope in Asia or a tropical rainforest in South of perennial beds. It should also serve as a quick guide America. The perennial plant trade offers more than for the most common and recommended perennials 3,600 species and cultivated varieties, and more are for Georgia. Common-sense tips from a professional added each year. With such an extensive palette, how landscaper’s perspective are also included. do you choose the right plant? Our advice is to follow three simple rules: Biology of Perennials The term “perennial” in the broadest sense means 1. stick to species and selections that are known to do plants that live for more than two years. This broad well in the area; the “bread-and-butter” plants; definition includes and that retain woody 2. match the optimum growing requirements; plant stems above ground in winter, including , cacti, the “right plant in the right place”; and succulents, grasses, , some and groundcov- 3. spend the extra time to maintain each species at ers. For the home gardener, however, it means a plant its peak performance (e.g., additional nutrition, with stems that usually die back in winter and a mid-summer trimming, regular deadheading); go system from which new foliage and grow the the extra mile. following year. Most perennials have herbaceous stems (e.g., , Achillea, , Liatris), but a few You don’t have to plant 50 species in one landscape, or develop woody stems (e.g., hardy , ). always use the latest and most fashionable cultivars – There is also a category of plants, called “tender peren- you could make a stunning display with five species or nials,” which are annuals that may over-winter occa- varieties that have been in the trade for 20 years. That sionally, depending on how severe the winter is (Figure said, you should strive to familiarize yourself with new 1). A true perennial has a capacity to survive from one hybrids that have improved tolerance to shade/sun, year to the next. Figure 1. (elephant ear; front left, heart-shaped foliage), a tender perennial, is shown here emerging from the ground along with Hosta, a perennial (back of bed, gray foliage). Tender perennials have become very popular in the trade; however, you should be familiar with each spe- cies and cultivar, as their cold tolerance varies.

Growing Perennials in Georgia Figure 2. Georgia Plant Hardiness Zone Map. Zones are based on average minimum winter temperatures. Many While perennial plants are found in almost every nat- other factors, such as summer heat, summer night tem- ural habitat around the world, not all plants can grow peratures, humidity and rainfall, affect plant performance well when they are cultivated in a different region of the and adaptability. globe. The best plant performance is achieved when the landscape habitat closely matches the plant’s endemic environment. Until recently, most plant catalogs listed only the cold hardiness zone when describing how far north a plant can be expected to survive (Figure 2).

Georgia has a diverse range of cold hardiness zones, ranging from zone 6a in the northeast corner of the state to zone 9a in the southern coastal part of the state.

Plants growing in Georgia also face a challenging com- bination of high summer temperatures and high hu- midity (Figure 3). Academicians, nurserymen, growers, and landscape professionals have found that growing Figure 3. Average days above 900 F (30-year annual aver- perennial plants in the Southeast justifies using a heat ages rounded to next highest class) in the state of Georgia. tolerance map as well -- one that describes a plant’s adaptability to summer heat. The American Horticul- to reduced vigor, small foliage and weak, stunted plants tural Society (www.ahs.org) provides information on and. The effects of heat damage are subtler than those plant heat tolerance in a detailed interactive map. of extreme cold, which can kill a plant quickly. Heat damage can first appear in many different parts of the Heat tolerance is more difficult to evaluate than cold plant -- buds may wither, may droop or tolerance; plants respond to cold by dying, to heat by become susceptible to pests, chlorophyll may disap- slowly declining. High night temperatures increase res- so that leaves appear white or brown, or piration; for every 160F rise in temperature, respiration may cease growing. Plant death from heat is slow and rate doubles. Plants use up their stored reserves, leading lingering.

UGA Extension Bulletin 1424 2 Landscape Basics: Success with Herbaceous Perennials Georgia also has a very diverse ecology, with more than tion in sandy soils causes plant stress from drought. In 100 distinct environments and at least eight major habi- fact, more perennials die from wet winter soils than from tats. These are generally grouped within three geological cold in Georgia. Amend perennial beds with organic regions: Mountains / Northwest, Piedmont and Coastal matter to improve soil conditions. Plain. Figure 3 shows that the Coastal Plains experience more days of temperatures over 900 F compared to more Research has shown that plant growth in Georgia cli- northern regions (Mountains), which plays a major role mates is typified by earlier-flowering, taller plants with in plant performance across the state. weaker stems due to accumulated heat – more so than in more northern . Tall forms tend to collapse with- The last two factors to consider when planting peren- out support; therefore, dwarf selections are usually more nials are rainfall and soil. The entire state, including the effective. Fertilizer may not need to be applied as gener- Mountains, receives moderate to heavy rain, which var- ously, particularly for tall plants as additional growth is ies from 45 inches in central Georgia to approximately not desired. Leggy, lanky growth and fewer flowers result 75 inches around the northeastern part of the state. The if too much nitrogen is applied. Coastal Plains experience hot, humid summers with fre- quent afternoon thunderstorms and mild, drier winters. Soil pH and Mineral Nutrients Wet, cool springs are typical. Since perennials are expected to live in a certain area for many years, it is very important to be sure the soil is Rainfall, when considered with various soils, affects amended to fit the plant’s needs. In addition to organic perennial plant survival and adaptability to Georgia’s matter, pay attention to soil pH. Too high or too low soil . The soils in Georgia are varied; generally, the pH may affect nutrient uptake, stress the plant and re- Coastal Plains have sandy, well-drained soils that are duce the plant’s chances of surviving more than one year. poor in organic matter, while the Piedmont and Moun- tain regions have heavier clay or clay-loam soils that Most perennials prefer a pH between 5.2 and 6.7 (slightly retain water well, with organic matter present in some acidic). Soil pH affects nutrient uptake (Figure 5). This areas (Figure 4). “Goldilocks” range assures that two important micro- nutrients -- iron (Fe) and manganese (Mn) -- are being Drainage becomes a very important factor in plant sur- absorbed by the plant roots in optimal concentrations. vival. Inadequate drainage in clay soils creates favorable If the pH is below 5, both of these elements can interfere conditions for root rots, and insufficient moisture reten- with the uptake of other nutrients. If the pH is higher than 7, Fe and Mn can become deficient. Symptoms of nutrient deficiency include yellow (chlorotic) tips and young foliage (Figure 6).

Figure 4. Georgia soil map (for detailed information, visit www.dot.ga.gov). Colors indicate different soil types. Figure 5. Nutrient availability chart. The red box shows the pH range in which mineral nutrient uptake is optimal. Landscape Basics: Success with Herbaceous Perennials 3 UGA Extension Bulletin 1424 sium [N-P-K]) in a 3-1-2 or 4-1-2 ratio. A 12-4-8 fertilizer, for instance, is a 3-1-2 ratio, and a 16-4-8 fertilizer is a 4-1-2 ratio. Research shows that phosphorus, the middle number in the analysis, is held by soils and does not leach with rains or irrigation as much as nitrogen or potas- sium do, so it is usually needed in lower amounts.

The most common types of fertilizer ap- plied to perennial beds in the spring are general-purpose 10-10-10 (N-P-K), 8-8-8 or 16-4-8. Other analyses, however, are sometimes more suitable for a given spe- cies (Table 4). The recommendations are based on pounds of nitrogen per 1,000 square feet per season.

• Heavy: 3 applications: 1 pound of Figure 6. Symptoms of phosphorus (top left), nitrogen (top right), iron 10-10-10/100 sq. ft./season: one at trans- (bottom left) and magnesium (bottom right) deficiencies. plant, one three to four weeks later, and Two other common deficiencies are phosphorus (P) another one three to four weeks after that. and magnesium (Mg). Phosphorus deficiency typical- • Moderate: 2 applications: 1 pound 10-10-10/100 sq. ly occurs in winter and manifests as purple or bronze ft./season: one at transplant and one mid-season. foliage color (on plants with foliage). Do not • Low: 1 application: 1 pound 10-10-10/100 sq. ft. at direct-supplement with phosphorus; instead, apply a transplant or in early spring before growth resumes. balanced fertilizer, such as 10-10-10, in the spring as leaves emerge and soil warms up. Magnesium defi- Fertility products can be formulated to deliver the ciency symptoms include interveinal chlorosis of lower plant food over a short- or long-term period. Be sure leaves (Figure 6). Georgia soils are lower in this im- to use a formula that fits your needs. Spring growth portant macronutrient; use magnesium sulfate (Epsom may require fast- acting fertilizer products, whereas salts) to remedy this deficiency. Nitrogen (N) deficien- summer fertilization may require a slow-release prod- cy is typified by chlorosis of older leaves (mild), pro- uct, including organic fertilizer. Remember that shade gressing to overall chlorosis (moderate to severe). areas and sandy soils require different levels of fertility than sunny garden soils. Periods of excessive rain or drought can affect nutrient levels and uptake. In winter, some perennials that have Below is a simple calculation for how much fertilizer to evergreen foliage can become purple or bronze in col- apply per bed. or. This may be a normal condition in the winter, but a warning sign of deficiencies in late spring. Calcium 1. For dry fertilizers (e.g., 16-4-8), divide the percent- and magnesium may be depleted. Only a soil test and a age of N into 10 (10/16 = 0.6 pounds). The result- foliage test will determine the right ratio of nutrients to ing number is the pounds of N to be applied per add to correct the problem. 100 sq. ft. 2. Determine the square footage of the bed (e.g., 5’ x Fertilization 50’, or 250 sq. ft.). A soil test, available through your county Extension 3. Multiply 250 sq. ft. x 0.6 (the application rate per office, is the best way to determine which fertilizer 100 sq. ft.) then divide into 100 = 1.5 pounds. analysis is most suitable. As a general guideline, most 4. The resulting number (1.5 pounds) is how much ornamental plants will benefit from a fertilizer having 16-4-8 fertilizer to apply to a 5’ x 50’ perennial bed. its primary nutrients (nitrogen, phosphorus and potas-

UGA Extension Bulletin 1424 4 Landscape Basics: Success with Herbaceous Perennials For further information on different fertilizer formula- tions and application rates, refer to “Care of Ornamen- tal Plants in the Landscape,” UGA Extension Bulletin 1065, and “How to Convert an Inorganic Fertilizer Recommendation to an Organic One,” UGA Extension Circular 853.

Perennials are much like shrubs in that they may re- quire high levels of fertility early in spring or summer, when they put on growth, and low fertility the remain- der of the year (Figure 7). The ability of a plant to take up nitrogen is also a function of season. Once leaves Figure 8. Monthly evaporation rates (20-year average) for are lost to frost, perennials do not need fertilizer. Athens, Ga. Plant perennials in October when evaporative water loss is reduced (arrow).

Figure 7. Nitrogen uptake throughout the year shows that fertilizer should be applied in spring during growth. Figure 9. Raised beds not only improve drainage but also provide better plant display. Organic compost should be Fall is the Best Time to Plant thoroughly tilled. There are many reasons for planting in the fall. The Perennial Bed Design most important reason is to give the new plants a chance to develop a sizable root system in the absence Planting schemes for perennial beds are usually mixed of high temperatures and transpiration rates (loss plantings incorporating annuals, perennials, shrubs of water from foliage). Root development may take and trees (Figures 10-11). several months, and by having this occur in the winter months, the plant is not stressed. A well-developed Shrubs and trees provide the “backbone” of the land- root system will be better able to withstand dry periods scape as well as winter interest, while annuals are used and times of high water loss due to high evaporation in as year-round complementary color (e.g., pansies and summer. Evaporation rates, and hence water demand, other winter annuals, and petunias and other summer drops off in October (Figure 8). annuals). The annuals are either placed to the outside of the bed or interspersed among the perennials and Bed Preparation woodies; the latter is utilized in the first year or two of Perennials require careful bed preparation to establish the installation to provide color and interest while the successfully. Remove all plant debris, amend the soil, other plants are still establishing. till to 12 to 18 inches and add fertilizer to new peren- nial beds. Using a coarse-grade compost or organic supplement will help the bed retain moisture longer (Figure 9). Coarse granite sand also is a good amend- ment for perennial beds if drainage needs to be im- proved.

Landscape Basics: Success with Herbaceous Perennials 5 UGA Extension Bulletin 1424 In general, there are three types of perennial beds (Figure 12):

• Island bed: A freestanding garden, usually kid- ney-shaped and often raised to promote drainage, can be viewed from all sides; • Perennial border: Double or single border with a backdrop of a wall, fence or woody shrubs that is generally viewed from one side; • Naturalized area: Established in an area of native plants (e.g., woodland garden or natural stream).

Figure 10. Perennials are skillfully interspersed among shrubs and trees in this commercial landscape in Atlanta. Daylily ‘Happy Returns’ (behind bench), Russian sage (lavender blooms) and shasta daisy (white blooms) are surrounded by boxwood hedge.

Figure 11. Perennials (, , Buddleia) are used Figure 12. Top: island bed; middle: perennial border; bot- as a backdrop to frame a water feature, while annuals (, tom: naturalized area. coleus) provide color and textural interest. Top: early summer; bottom: late summer.

UGA Extension Bulletin 1424 6 Landscape Basics: Success with Herbaceous Perennials When designing large perennials beds that are to be On the other hand, when designing smaller beds and viewed from a distance or by passing vehicles, a sim- inviting a closer look, a more intense theme with many ple theme, both in color and species, is most suitable colors and textures is appropriate (Figure 14). (Figure 13).

Figure 14. This mixed annual and perennial bed may ap- pear too “busy” but the goal was to have customers spend more time in the adjoining retail area.

Yellow, orange and red are the most dramatic colors and should be used sparingly. Green, blue and purple recede and should be grouped together. When creating a vibrant color border, surround the bold colors with white or silver to avoid a harsh, gaudy look. Common two-color complementary schemes are yellow and pur- ple, red and green, and orange and blue. Use plants with small flowers en masse (e.g., Russian sage) and plants with large blooms (e.g., hardy hibiscus) as specimens.

Figure 13. Top: Pan- Selection and Planting icum ‘Heavy Metal’ Planning is the key to success when designing and in- provides a backdrop for fulgida; stalling a perennial bed. Know the plant’s requirements middle: a comple- for sun or shade, moisture and nutrition (Tables 1, 2, 4). mentary three-color One of the most common pitfalls is placing species that theme, Vitex (blue), require full sun for best growth and bloom in areas that Echinacea (pink) and get fewer than six hours of sunshine (Figure 15). Rudbeckia (yellow), provides drama and grabs the viewer’s attention; bottom: on a smaller scale, the same blue- red-yellow theme works well with blue and red and yellow .

Landscape Basics: Success with Herbaceous Perennials 7 UGA Extension Bulletin 1424 Figure 15. Right plant in the right place. Top: , lamb’s ear and Coreopsis (red “x”) are full-sun plants struggling under the heavy shade in this bed. Hosta (green star) is a proper choice, while purple heart (, purple star) can tolerate shade but for intense foliage color needs more sun. Crocosma exhibits fewer blooms in partial shade (bottom left) compared to no shade (bottom right). Plantings are of the same age and cultivar located throughout one commercial account.

Plant Selection Tips: coccinea ‘Lady-in-Red’, a perennial in most of the • Know the habit and final size of the perennial to state) will not grow larger than 2 feet. Some peren- prevent a vigorous plant overtaking less vigorous nials (e.g., leucantha) do not perform well if specimens (Table 4). Spacing perennials is critical young plants receive competition from other plants as many start small and grow large in width and for light, water and nutrients during the establish- height. Space plants according to their mature size ment phase. When planted too far apart, on the or the size they will achieve in the third year of other hand, more will be needed to control growth. Pay close attention to species and cultivars; weeds and keep the soil cool and moist. Unless a for example, blue sage (Salvia guaranitica) can grow sufficient layer of mulch is maintained, soil evap- to 5 feet tall and wide, while lady red salvia (Salvia oration may cause heat stress and delay growth.

UGA Extension Bulletin 1424 8 Landscape Basics: Success with Herbaceous Perennials Additional space may be required for perennials • Plant groups of each species/cultivar rather than that form a colony (e.g., Liatris). Bottom line: use spotting single plants throughout the bed. a planting density that allows sufficient room for • Leave grass foliage and heads for winter interest. plants to grow successfully to maturity. • Know the bloom period to plan a continuous • Know the soil type preference and the pH require- bloom sequence and year-round interest. Arrange ments to ensure the likelihood of survival year after plants so certain areas of the bed are in bloom at year. same time. • Know pest and disease tendencies, which will help • Choose masses of fewer selections to increase you plan for problems that may arise in the future visual impact and simplify maintenance. This will so that you can build a preventive pest control also help less experienced maintenance staff to dis- program. For instance, species in the daisy family cern weeds from the perennials, especially in spring () are when plants are emerging. prone to powdery • Add annuals/shrubs (see Figure 11) and bulbs for mildew, while color/texture (Figure 17). aphids can dev- astate a milkweed Beware of Invasives! (Figure 16). There are quite a few perennials that are so vigorous • Know the life that they can become invasive. salicaria, Soli- span to help you dago species and Physostegia virginiana can be invasive plan replacements in cultivated gardens, as can and Oenothera. and establish Many of these species are native to nearby states, but where the plant not native to Georgia. Plants from other countries may will be placed in also escape cultivation and become truly invasive and the landscape. damaging to local environments (Figure 18). Be sure Most long-lived the plants you select are not invasive. Check www. plants should be gaeppc.org and www.eddmaps.org/species/ for infor- placed towards Figure 16. Aphids on , mation on in Georgia and surround- the back and side milkweed. ing states and alternatives for non-native invasive of the bed, or in the middle, to allow replacement plants. of less long-lived specimens without disturbing the more permanent specimens. A good way to handle more aggressive species is to • Group plants by growth rates to facilitate the divi- place them in a challenging location in the plant- sion process (see “Bed Renovation”). ing. For example, perennial plumbago (Ceratostigma • Place perennials in triangle formations to maxi- plumbaginoides), an excellent perennial for sun, can be mize flowering and foliage effects. planted on a slope or in a rock garden with limited soil

Figure 17. Daffodils are interplanted with Rudbeckia in this island. After the daffodil blooms fade, their foliage needs to remain to feed the underground . During this time the Rud- beckias screen the daffodil foliage.

Landscape Basics: Success with Herbaceous Perennials 9 UGA Extension Bulletin 1424 Figure 18. Even though irises are commonly used in rainwater gardens, pseudacorus (yellow- flag), I. syberica (Syberian iris), I. pallida (sweet iris) and I. ensata (Russian iris) are considered invasive species by the Center for Invasive Species and Health at the University of Georgia (www.eddmaps.org). The yellow-flowered species in this planting is . in order to check its growth. Be on the lookout for new hybrids and cultivars that are sterile (i.e., not-reseed- ing) or less vigorous (dwarf), as they offer the good qualities with none of the bad.

Many ornamentals have variegated foliage, including stripes or white/yellow stripes on foliage margins, or overall cream, yellow, chartreuse or gold leaves. As a general rule of thumb, these varieties are not as vigor- ous as the all-green form. This can be both a positive, because the plant will not be as aggressive, and a neg- ative, because the plant may not thrive and adapt well due to reduced photosynthesis and limited reserves. Always install the right plant in the right place and be ready to properly maintain it (Figure 19).

Popularity of native plants is growing. Be willing to explore their potential. Not only will you be protecting Georgia natural , but you will also provide long-term benefits, such as food and shelter for many native insects and animals, which can control invasive pests, reduce the need for pesticides and offer a sus- Figure 19. Lysimachia ‘Aurea’ is often planted as an ever- tainable way to maintain healthy landscapes. For more green in the shade; however, there are sever- information, refer to Native Plants for Georgia under al issues: L. nummularia is species listed as invasive; under “Resources.” optimal moist and shady conditions, it quickly spreads, and the slower-growing yellow-leafed form ‘Aurea’ often reverts General Culture back to the green form (shown here), which will take over. Pot Sizes To check its growth, do not plant under optimal conditions and trim away any green as they appear. There are four popular sizes used in the perennial plant trade: 3-1/2” pot, 4-1/2” Perennial, #1 Perennial and low-budget installations, but will dry out faster and #2 Perennial (for detailed information on pot sizes and need more frequent irrigation until they get estab- volumes, refer to http://www.anla.org/%5Cdocs%- lished. In addition, they may not be in bloom until 5CAbout%20ANLA%5CIndustry%20Resources%- later. The larger sizes have instant impact because of 5CANL AStandard2004.pdf) . Each has its advantages plant size and bloom, and their establishment period is and disadvantages. The smaller sizes are suitable for shorter; on the downside, they can be cost-prohibitive.

UGA Extension Bulletin 1424 10 Landscape Basics: Success with Herbaceous Perennials Mulch pre-emergence has recently become available provide many benefits, including holding on the market. For specific information on weed con- moisture in the soil, helping prevent weed growth, trol, consult UGA Georgia Bulletin 979, inhibiting certain soil-borne foliar diseases and insu- in Home , available at your county extension lating plant roots from temperature extremes during office or at caes.uga.edu/publications. summer and winter. The best mulch is organic, fine-textured and non-matting. Examples include Wildlife straw, pine mini-nuggets, hardwood chips and Urbanization destroys wildlife habitat, pushing adapt- cypress shavings. Fall leaves make an excellent and able wildlife species to move into urban/suburban economical mulch and add valuable humus back to landscapes. Landscapes contain many plant species the soil (thus improving soil structure as they decom- that provide food and shelter for wildlife. As a land- pose). Along with yard trimmings, leaves are suitable scaper you have a choice: inhibiting incursions by for residential accounts. Pecan hulls, a by-product of unwanted animals or promoting wildlife visits (e.g., the pecan industry, are used successfully as mulch in hummingbirds, bees and butterflies). Increased contact south Georgia. Grass clippings are not a good source with wildlife may either lead to customer complaints of mulch because they tend to mat down and inhibit or delight. the flow of water and nutrients into the soil. They also may introduce weeds. Inorganic mulches, such as rock, Animals that do the most damage to ornamental plants gravel and marble, are good soil insulators but they in the landscape include deer and rabbits. Table 3 lists absorb and re-radiate heat in the landscape, increasing perennial plants generally avoided by deer. More infor- water loss from plants. mation on mechanical or chemical means of keeping wildlife from perennial plantings can be found under How much mulch to apply depends upon irrigation “Resources.” plans, local soils and local weather. If you are designing a low-water-use bed, 4 to 6 inches of pine straw or pine Planning Maintenance bark will be required. An average residential garden For best performance, perennial beds need to be main- will require a 3- to 5-inch layer. On commercial instal- tained, which demands an investment of labor and lations with irrigation, 2 to 3 inches of mulch will do. time. Make sure that you include this extra time and labor when you prepare a bid or estimate. Make a good Weed Control case to the customer about why this expense is in Because perennials live their lives in one place, sea- their best interest. Use knowledgeable staff to maintain sonal weeds can be a problem. Weeds compete with residential accounts with numerous species (train your perennials for water, nutrients and sunlight. Weeds can staff to recognize what is a weed and what is an orna- be controlled mechanically (by hand, with mulch and mental!) landscape fabric) or chemically (with ). For chemical control, pre-emergence and post-emer- Removing spent flower heads, called deadheading, is gence herbicides are available. Pre- emergence herbi- very important to most perennials (Figure 20). For cides control weeds in the early stages of weed seed example, species will die mid-summer if germination, and post-emergence herbicides are used the spent flowers are not removed. This is because too to kill established weeds. Be aware that pre-emergence many food reserves (i.e., sugars, the product of pho- herbicides need water to move (activate) into the zone tosynthesis) go into the seeds, and our hot Georgia where weed seeds germinate, while post-emergence summers use up a great deal of reserves with respira- herbicides need a certain period of dryness after appli- tion. The plant literally starves to death. Removing the cation. Also bear in mind that a single application of flower head before it goes to seed saves photosynthates pre- or post-emergence herbicide will not provide 100 for growth. Plants such as Echinacea (purple cone flow- percent weed control; for that you will need to com- er) will simply stop growing and stop putting up new bine several weed control techniques. flowers if they are not deadheaded. For continuous bloom and less disease, remove spent flowers regularly. Use pre-emergence herbicides in medians and other In addition, perennials with tendencies to reseed will limited-access beds. Mulch bark impregnated with be discouraged from doing so.

Landscape Basics: Success with Herbaceous Perennials 11 UGA Extension Bulletin 1424 Figure 20. Salvia nemorosa (Woodland sage) blooms in early summer (left), by midsummer only the seedheads are visi- ble (right). If the plants were deadheaded after the first flush, a second flush of blooms could have appeared, providing a nice backdrop to the . Perennial Bed Renovation In Georgia, it is recommended that perennial beds be dug up and renovat- ed every three years. Renovation reduces soil compaction, adds back organic matter, increases plant spacing and improves air cir- culation, thereby Figure 21. When perennials grow in one place for reducing disease extended time, there is competition for water and nu- and invigorating the trients. Roots/ also become overcrowded, which was the case in this Iris colony (left), leading planting (Figure 21). to loss of vigor and death in the center of the clump As with initial plant- (as happened with this Pampas grass (right)). ing, removing the plants, dead leaves and mulch before adding compost The general rule of thumb is to divide spring-flowering and amendments is recommended. Replanting is perennials in the fall and fall-flowering perennials in usually done the same day or the very next day. In the spring. essence, the perennial underground and aboveground mass is divided and smaller sections are planted back Fibrous roots (Figure 22). Many perennials form in the bed. colonies of plants that have interconnecting fibrous

UGA Extension Bulletin 1424 12 Landscape Basics: Success with Herbaceous Perennials Figure 22. Dividing perennials with fibrous roots (arrow indicates growing point).

Figure 23. Dividing perennials with rhizomes involves cutting the into sections. root systems (e.g., Phlox, Salvia, and Eu- patorium). The only reliable method of division is to identify groups of growing points, lift large sections of the root mass with a pitchfork or shovel and then pull the clumps apart to obtain individual sections with growing points.

Rhizomatous Perennials (Figure 23). Many peren- nials, such as Iris, Canna, daylily and blue anise sage, have rhizomes that must be lifted, washed and then hand cut. Each section of root must have a new eye or growth area.

Dividing Hostas (Figure 24). Hostas are particularly Figure 24. Division of Hosta. easy to divide, as the individual plants form separate- ly. Simply lift the entire colony, remove soil from the roots by applying a spray of water, then pull the clumps apart.

Landscape Basics: Success with Herbaceous Perennials 13 UGA Extension Bulletin 1424 Spreading Perennials (Figure 25). Spreading perenni- als can often be divided as large clumps. Each clump is planted as a unit. Some perennials, such as thrift and , can also be propagated by making individu- al stem cuttings. Remove clusters from the outer areas of the colony to reduce its size. Pull the sections apart into individual stem pieces. A rooting hormone may expedite root formation when applied to the base of the stems, but many perennials do not need a rooting hor- mone if cuttings are taken in early spring or mid-fall. Place individual sections in prepared soil, and bury the lower one-third of the stem. Water-in cuttings thor- oughly and keep them moist for the next few weeks. If this procedure is followed in the fall, each stem will root Figure 25. Dividing spreading perennials involves cutting and form a new plant by spring. These new plants can the creeping stems into sections and replanting them. be re-dug mid-summer and transplanted.

Marketing Perennials in the Landscape and Managing Customer Expectations Using perennials in landscape installations can be a rewarding experience for your customers and a prof- itable one for you; however, there are some common misconceptions regarding perennials that you and your customer need to be aware of.

Perennials are not low-maintenance -- they require wa- tering, fertilizing, shaping, deadheading, fall mulching, spring cleaning, dividing, replacing and insect, disease and weed control. Some perennials grow best when di- vided every few years. Perennial bed renovation should be considered every three to five years. All of these tasks Figure 26. Along with the beautiful Tiger Swallowtail butter- can be built into the maintenance bid and properly ad- fly and the Silver Spotted Skipper, at least 5 bumblebees dressed from the outset. (circled in red) are enjoying the blooms of this .

Perennials take time to fill space. A popular proverb Perennial plants can be a valuable addition to your describes their growth: “The first year they sleep, the plant palette; they can bring you return customers and second year they creep, and the third year they leap!” boost sales if you follow three simple rules: plant the Many plants start small and get very large. Make sure right plant in the right place, use plants that do well in you leave them adequate “elbow room” and assure your the area, and spend a few extra resources on mainte- customer that they are properly spaced. nance.

Customers want flowers and butterflies but they may not recognize that the same sweet nectar brings other insects as well (Figure 26). Bees and wasps may be a nuisance and some people are allergic to their sting. You need to let your customer know that next to the mailbox may not be the best location for that “butterfly magnet.”

UGA Extension Bulletin 1424 14 Landscape Basics: Success with Herbaceous Perennials Perennial Planting Gallery The following photos are of commercial installations using perennial plants.

Top: Russian sage and shasta daisy surrounded by boxwood hedge, which provides support for the tall-stemmed perennials.

Bottom: A dry, full-sun, raised planter with (center and insert, in bloom), evergreen (chartreuse) and hens- and-chicks (burgundy).

Landscape Basics: Success with Herbaceous Perennials 15 UGA Extension Bulletin 1424 Top: Mixed bed with variegated Liriope, Canna and Liatris.

Bottom: Lysimachia ‘Aurea’ with dwarf Loropetalum (burgundy foliage) provide good colors, contrast and evergreen groundcover; the small size of the perennials works well with the crape myrtles to provide good visibil- ity for traffic.

UGA Extension Bulletin 1424 16 Landscape Basics: Success with Herbaceous Perennials Left: All-perennial bed with Iris, , lamb’s ear and yarrow.

Right: Canna interplanted with Brazilian . The aggressive Canna is constrained by the narrow concrete bed, while the tall flower stems of the Verbena offer visual interest and contrast to the coarse Canna foliage.

Above: Ice plant (pink flowers), Sedum ‘Autumn Joy’ and bird nest Picea. The drought-tolerant evergreen perennials are a good choice for a South-facing bed, and the short habit allows for clearance from the windows; also notice the wavy pattern formed by the ice plant.

Right: Heuchera interplanted with Lycoris (red flower); both work well in the narrow bed and against the white siding.

Landscape Basics: Success with Herbaceous Perennials 17 UGA Extension Bulletin 1424 Left: Sedum edged with Liriope for a client who wanted evergreen and low-maintenance.

Right: Yarrow, shasta daisy and Miscanthus ‘Gold Bar’ work well in this drought-tolerant, low-maintenance bed.

Top: A mixed-shade bed with two varieties of Heucheras -- lenten and cast iron plant – combines a good use of evergreen foliage and foliar textures.

Bottom: A single-species planting of Hosta ‘Patriot’ under evergreen Japanese cedar.

UGA Extension Bulletin 1424 18 Landscape Basics: Success with Herbaceous Perennials Table 1. Quick reference of recommended perennial genera* for sun. Common Name Scientific Name Common Name Scientific Name Yarrow Achillea Helen’s Flower Helenium Anise Hyssop Agastache Orange Sunflower Heliopsis Hollyhock Alcea Daylily Hemerocallis Lady’s Mantle Rose Mallow Hibiscus Ornamental Candytuft Arkansas Blue Star Amsonia Iris Iris Bluestem Grass Andropogon Lantana Lantana Windflower Anemone Lavender Wormwood Artemisia Rose Campion Lychnis Butterfly Weed Asclepias Shasta Daisy Aster Aster Gayfeather Liatris False Indigo Baptisia Bee Balm Monarda Bellflower Catmint Bachelors Buttons Centaurea Switch Grass Ravenna Perennial Plumbago Ceratostigma Tickseed Coreopsis Balloon Flower Platycodon Larkspur Consolida Phlox Phlox Crocosmia Crocosma Black Eyed Susan Rudbeckia Pinks Dianthus Russian Sage Perovskia Coneflower Echinacea Sage Salvia Joe Pye Weed Lavender-Cotton Santolina Spurge Euphorbia Pincushion Flower Ice Plant Delosperma Stonecrop Sedum Blanket Flower Gaillardia Lamb’s Ear Stachys Whirling Butterflies Gaura Stoke’s Aster Stokesia Cranesbill Speedwell * Not all species in each genus are suitable for Georgia — for species and cultivars, refer to Table 4.

Table 2. Quick reference of recommended perennial genera* for shade. Common Name Scientific Name Common Name Scientific Name Bugbane Actaea Leopard Plant Ferfugium Lady’s Mantle Achemilla Lenten Rose Helleborus Anemone Anemone Coral Bells Heuchera Columbine Plantain Lily Hosta Jack-in-the-Pulpit Arisaema Ligularia Ligularia Goatsbeard Aruncus Virginia Bluebells Wild Asarum Cinnamon Osmunda False Spirea Astilbe Mayapple Painted Fern Athyrium Jacob’s Ladder Polemonium Pig Squeak Bergenia Solomon’s Seal Polygonatum Bugloss Brunnera Christmas Fern Polystichum Turtlehead Chelone Lungwort Lily-of-the-Valley Convallaria Meadow Rue Thalictrum Bleeding Heart Dicentra Foam Flower Tiarella Autumn Fern Dryopteris Toad Lily Tricyrtus Snakeroot Eupatorium Trillium * Not all species in each genus are suitable for Georgia — for species and cultivars, refer to Table 4.

Landscape Basics: Success with Herbaceous Perennials 19 UGA Extension Bulletin 1424 Table 3. Perennials generally avoided by deer. Common Name Scientific Name Common Name Scientific Name Yarrow Achillea Iris Iris African Lily Lavender Lavandula Anise Hyssop Agastache Cardinal Flower Lobelia Ornamental Onion Allium Shasta Daisy Chrysanthemum Elephant Ears Alocasia/Colocasia Gayfeather Liatris Bluestem Grass Andropogon Bee Balm Monarda Windflower Anemone Catmint Nepeta Columbine Aquilegia Oreganum Jack-in-the-Pulpit Arisaema Poppies Papaver Wormwood Artemisia Russian Sage Perovskia Butterfly Weed Asclepias Mayapple Podophyllum Aster Aster Christmas Fern Polystichum False Indigo Baptisia Green Jerusalem Sage Phlomis Boltonia Boltonia Switch Grass Ravenna Bellflower Campanula Rosemary Bachelors Buttons Centaurea Black Eyed Susan Rudbeckia Perennial Plumbago Ceratostigma Sage Salvia Tickseed Coreopsis Lavender-Cotton Santolina Pinks Dianthus Pincushion Flower Scabiosa Foxglove Stonecrop Sedum Coneflower Echinacea Hens-and-Chicks Joe Pye Weed Eupatorium Lamb’s Ear Stachys Spurge Euphorbia Stoke’s Aster Stokesia Ice Plant Delosperma Tanacetum Blanket Flower Gaillardia Foamflower Tiarella Sweet Woodruff Gallium Meadow Rue Thalictrum Perennial Sunflower Helianthus Society Garlic Tulbaghia Lenten Rose Helleborus Speedwell Veronica

UGA Extension Bulletin 1424 20 Landscape Basics: Success with Herbaceous Perennials -

- - - - - I. tectorum D. exima (wild bleed Additional Notes tility; no drought resistant organic, well drained soils; mulch heavily. Nectar source; drought and deer tolerant; low fertility; stake young plants; divide @ 5 years. Fine-textured foliage; ing heart) is native to Georgia; spring flower; unusual flowers; moderate fertility; high organic soils; keep moist. Great flowers; near fundations; moderate fer erate fertility; reseeds.’Freckle Face’ is shorter, is shorter, erate fertility; reseeds.’Freckle Face’ 12-15 “ stem. Drought-tolerant; attractive to butterflies. Aromatic foliage; , the color ‘brings’ all sur - Aromatic foliage; , the color ‘brings’ rounding plants together; drought-tolerant; deer tolerant; moderate fertility; spreads rapidly. Native; drought-tolerant; foliage is food for Mon arch butterfly caterpillars. Many cultivars, some very vigorous; no drought, heavy fertility. Drought and deer tolerant; aromatic foliage; nectar source; attractive to butterflies; moder ate fertility; spreads quickly; mildew can be a problem Iris hybrids (bearded iris) and I. kaempferi (Japanese iris), bloom in this order; (Japanese roof iris) is a durable plant; drought and deer tolerant; moderate fertility; well drained spoils; rot and borers can be a problem. Nectar souce; drought and deer tolerant; mod erate fertility; mildew can be a problem; dies out in wet warm weather. Nectar source; drought and deer tolerant; mod * * * * * * * * Sun * * * * * * Shade Partial Exposure * * Shade Spacing Spacing (“) 12” 12” 14” 12” 8” 15-18” 12” 10-12” 6” 18-24” 8”

2 Bloom SP SP+/Su Sp+ Su/F Su+/F Su Su+/F SP+/Su SP/-Su Su/F Su Habit Upright Groundcover Upright Upright Mounding Mounding Upright Spreading Upright Upright Upright

1 Color B W,P B Y,R,O S, G O all W,R,P all Y R, L Y, O, Height 24-40” 20-25” 18-30” 1-2½’ 20-40” 1-2’ 1-5’ 18-36” 28-40” 36-50” 18-28” Notable Cultivars ‘Salicifolia’ ‘Two Times Blue’ Times ‘Two ‘Oranges and Lemons’ ‘Oranges and Lemons’ ‘Summer Kiss’ ‘King of Hearts’ ‘Formosa’ Silver King’ ‘Silver Silver King’ Mound’ ‘Hello Yellow’ October Skyes’ ‘Country gardens’ ‘Cambridge Scarlet’ ‘Mahogany’ numerous ‘Autumn Colors’ Freckle Face’

Common Name Blue Stars Amsonia tabernaemontana Blue Nile Lily Agapanthus praecox Table 4. Selected perennials for Georgia. Blanket Flower Gaillardia Bleeding Hearts Dicentra spectabilis Artemisia Artemisia ludoviciana Asclepias Asclepias tuberosa Aster Aster Bee Balm Monarda didyma Bearded Iris Iris hybrida Black Eyed Susan Rudbeckia triloba Lily Belamcanda chinensis

Landscape Basics: Success with Herbaceous Perennials 21 UGA Extension Bulletin 1424 - - - - is perennial species Additional Notes Evergreen groundcover; tolerates more sun providede adequate moisture; cultivars avail able with variagated or bronze foliage; nectar source; low fertility; no drought resistance; deer tolerant; may melt out in summer heat; Nectar source; Drought and deer tolerant; mod erate fertility; comes up late - mark location; Spring flower; drought and deer tolerant; mod erate fertility;trim flat before mid summer growth flush for even blums; Drought-tolerant; attracts butterflies; Centaurea montana Decorative foliage; moderate fertility; moderate foliage; Decorative soils; well organic tolerant; no drought soils; spindly in low light; drained Low fertility;no drought toleranr; deer toler ant;inconspicuous; can be invasive in moist areas; Nectar source; drought and deer tolerant; good winter foliage; moderate fertility; well drained soils; root rots in summer can be a problem; Not all variaties are cold-hardy; taller varieties require staking; No drought tolernat; moderate fertility; bleaches in sun when dry; Nectar source; drought and deer tolerant; and deer tolerant; drought source; Nectar soils; clean well drained fertility; heavy in winter; debris away Trellis ; Heavy fertility; deer tolerant; tolerant; deer fertility; vine; Heavy Trellis other year and every prune @ 3 years after; there * * * * * * * * * Sun * * * * * Shade Partial Exposure * * * Shade * Spacing Spacing (“) 14” 4-6” 10” 6” 24-46’ 12” 8” 8-10” 18-24’ 12” 8” 8”

2 Bloom Su Sp Su SP Su+ -Su SP/F SP Su/F SP Su SP Habit Vine Groundcover Upright Groundcover Upright Upright Groundcover Groundcover Upright Groundcover Upright Upright mound Vine

1 Color Pu B,W,P Y, R W B B G P, W -B Pu P R,Y Height 3-5’ 2-3” 18-30” 8-12” 3-4’ 12” 6-8” 8-12” 1-3’ 15-20” 36-50” 30-40’ Notable Cultivars ‘Album ‘Baha Red’ ‘Album ‘Valfredda’ ‘Multicolor’ ‘Valfredda’ ‘Gay Butterflies’ ‘Alexander White’ ‘Little Gem’ ‘Dark Knight’ ‘Blue Mist’ ‘Alba’ ‘Sternbergii’ ‘Chameleon’ ‘Petite’ ‘Bath’s Pink’ Pink’ ‘Bath’s ‘Petite’ ‘Flore-plena’ ‘Pink Bouquet’ ‘Sensation’ ‘Purple Palace’ ‘Hawaiian White’ ‘Hawaiian ‘Jekyll’ Common Name Coral Vine Coral leptopus Antigonon Bugle Weed Bugle Weed Ajuga reptans Weed Butterfly Aesclepias tuberosa Candytuft Iberis sempervirens Caryopteris Caryopteris Cornflower Centaurea Chameleon Plant Hottuynia cordata Cheddar Pink Dianthus grantianopolitanus Chrysanthemum Chrysanthemum Coral Bells Heuchera americana Crinum Lily Crinum hybrida Cross Vine Cross Bignonia capreolata

UGA Extension Bulletin 1424 22 Landscape Basics: Success with Herbaceous Perennials - are are lutea D. and Additional Notes Fragrant flowers; moderate fertility; no moderate flowers; Fragrant soils; drained well tolerant; drought Drought and deer tolerant; Full sun if and deer tolerant; Drought declines in heat; fertility; heavy moist; d’Oro’ ‘Stella available; cultivars numerous one; is the earliest-blooming Wispy flower spikes; drought-tolerant; spikes; flower Wispy Nectar source; heavy fertility; deer toler deer fertility; heavy source; Nectar rapidly; spreads ant; Nectar source; drought tolerant; moderate moderate tolerant; drought source; Nectar for bulb soil; scout well drained fertility; divide @ 3 years rot; - fertili low and deer tolerant; Drought in spring; mark site; up late ty;comes Nectar source; moderate fertility, no fertility, moderate source; Nectar soils; mulch high organic tolerant; drought available; colors many moist; keep heavily; in grown best foliage; fern-lke attractive shade; perennials Digitalis X mertonensis Digitalis Nectar source; deer tolerant; moderate moderate deer tolerant; source; Nectar in full sun; fertility;scalds Drought-tolerant; attractive to butterflies; attractive Drought-tolerant; Nectar source; heavy fertility; no drought no drought fertility; heavy source; Nectar do not crowd; deer tolerant; tolerant; Large flowers; moderate fertility;no moderate flowers; Large drained well organic, tolerant; drought in North Georgia; soils; mulch heavily * * * * * * * * * Sun *

* * Shade Partial Exposure * * Shade Spacing Spacing (“) 8” 12” 24” 6” 6” 12” 12-18” 12” 8” 16” 12”

2 Bloom Su Su Su- Su- SP/-Su Su- SP SP+ Su Su/F Su-/F Su/F Habit Upright Upright Upright Upright Mound Groundcover Upright Upright Upright Upright Upright Upright

1 Color P all W, P W, W,P P, W, L W, P, B, Y P W,P,Y,L W Y,R,O all all Height 28-60” 15-20” 2-3’ 4-6” 24-30” 28-56 24-30” 2-6’ 20-24” 1-2½’ 20-36” 12-25” Notable Cultivars ‘Rubrum’ ‘Stella Supreme’ Supreme’ ‘Stella ‘Ribbonnette’ ‘Black Falcon’ ‘Syskiyou Pink’ ‘Syskiyou ‘Bellissima White’ ‘Alba’, ‘Floristan ‘Floristan ‘Alba’, Violet’ ‘Screeming Yellow’ ‘Screeming ‘Bridal Veil’ ‘Erica’ ‘Bridal Veil’ ‘Gigantea’ ‘Gigantea’ Island’ ‘Krik ‘Variegatum’ ‘Baby Cole’ ‘Baby ‘Burgundy’ ‘Country Gardens’ ‘Country ‘Jersey Beauty’ ‘Jersey

Common Name Daylily Daylily hybrida Hemerocallis Gaura Gaura Gaura English Daisies Gay Feather Feather Gay Liatris spicata False Indigo Indigo False australis Baptisia False Spirea Spirea False x ardensii Astilbe Foxglove Foxglove ferruginea Digitalis Fragrant Solomon’s Seals Solomon’s Fragrant odoratum Polygonatum Blanket Flower Flower Blanket Gaillardia Aster Garden Aster Garden Garden Garden Dahlia hybrida Garden Lilies Garden speciosum

Landscape Basics: Success with Herbaceous Perennials 23 UGA Extension Bulletin 1424 - - - - Additional Notes Very floriferous; moderate fertility;well fertility;well moderate floriferous; Very soils; do not mulch heavily; drained Easy to grow; nectar source; foliage foliage source; nectar grow; to Easy butterfly of numerous caterpillars sustains be can and deer tolerant; species; drought invasive; Nectar source; drought and deer tolerant; and deer tolerant; drought source; Nectar need may young plants fertility; moderate staking; Aromatic foliage; drought and deertoler drought foliage; Aromatic - aggres fertility; low source; nectar ant; leggy if fertilized; gets sive; Vigorous growth habit; well-drained soils; habit; well-drained growth Vigorous bloom continuous for old flowers remove ing; Nectar source; drought and deer tolerant; and deer tolerant; drought source; Nectar with mulch cover not fertility;do moderate in winter; Nectar source; Drought and deer toler Drought source; Nectar late until branches do not cut frosted ant; April; until spring, mound with leaves Drought tolerant; moderate fertility; well fertility; moderate tolerant; Drought get can runners; by soils’ spreads drained when mature -like Foliage colors range from yellow-green to to yellow-green from range colors Foliage variegated many blue-green; to dark green fer moderate available; also are varieties food; divide soils; deer tility; high organic @ 5 years; Nectar source; trellis vine; drought and vine; drought trellis source; Nectar trim @3 fertility; moderate deer tolerant; shape/vigor; keep to years * * * * * * * * Sun * * * * * Shade Partial Exposure * * Shade Spacing Spacing (“) 10” 6” 12-18” 6-8” 12-18” 6” 36-54” 4’ 15-18” 36-60’

2 Bloom Su Su+/F Su Su F SP+/F Su Su Su SP Habit Groundcover Upright Upright Upright Groundcover Groundcover Mounding Upright Mounding Vine

1 Color W G P W,P,Y,G B,W L,Y,P,W, R L,Y,P,W, Y, R P W R,O Height 24-56” 24-54” 15-20” 1-2’ 4-6” 48-70” 60-120” 15-28” 4-6’ 15-30” Notable Cultivars ‘Peter Pan’ ‘Peter ‘Atropurpureum’ ‘Gold Plate’ Plate’ ‘Gold Variety’ ‘Parker’s ‘High Tide Blue’ ‘Strong Red’ ‘Strong ‘Miss Huff’ ‘Variegata’ ‘Patriot’ ‘Major Wheeler’ ‘Hortensis’ Common Name Goldenrod Goldenrod Joe Pye Weed Weed Joe Pye purpureum Eupatorium Golden yarrow Golden yarrow Achillea filipendula Hardy Ageratum Ageratum Hardy Ageratum houstonianum Hardy Ice Plant Ice Plant Hardy Delosperma cooperii Hardy Lantana Lantana Hardy camara Lantana Harlequin Glory Bower Harlequin Glory Bower - trichoto mum Hosta Hosta Hosta Hummingbird Hummingbird Honeysuckle sempervirensLonicera Japanese Aster Japanese Aster pinnatifida Kalimeris

UGA Extension Bulletin 1424 24 Landscape Basics: Success with Herbaceous Perennials - - - - (mondograss), (mondograss), (Lenten rose) flowers flowers rose) (Lenten (snakebeard); evergreen evergreen (snakebeard); Additional Notes H. orientalis O. jaburan O. Foliage declines in heat; nectar source; source; nectar declines in heat; Foliage tolerant; drought fertility;no moderate min soils; leaf high organic deer tolerant; be a problem; can ers Nectar source; drought and deer tolerant; and deer tolerant; drought source; Nectar soils; well drained fertility; low - fertili blooming;Heavy source;Fall Nectar do deer tolerant; tolerant; ty; no drought plants; young not crowd (Christmas rose) blooms rose) niger (Christmas early spring; coarse-textured to November foliage; fertility; spring; moderate late in mid- to soils; reseeds; high organic Nectar source; fragrant; moderate fertility; fertility; moderate fragrant; source; Nectar high deer tolerant; tolerant; no drought soils; organic Nectar source; moist soils; divide clumps soils; divide clumps moist source; Nectar in early spring; Drought and deer tolerant; moderate fer moderate and deer tolerant; Drought slowly; tility; spreads ; variegated snakebeard snakebeard variegated groundcovers; liriope variegated with confised often and L. spicata (bordergrass), Liriope variegat lilyturf);(creeping evergreen; ed forms with attractive foliage; flowers flowers foliage; with attractive ed forms bor source; nectar also attractive; spikes tolerant; and deer der planting;drought growing; slow fertility; moderate * * * * Sun * * * * * Shade Partial Exposure * * * * Shade Spacing Spacing (“) 4-6” 12” 12” 6” 15-18” 12” 4-8” 5-8” 4”

2 Bloom SP+ Su+/F W/SP SP Su+ Su+/F Su Su SP Habit Groundcover Upright Mounding Upright Upright Spreading Groundcover Groundcover Mounding

1 Color Y P, L ,Y W,P,L W R,B B, W, L W, B, Pu L W,P,B,Y Height 6-8” 40-54” 15-24” 8-12” 2-3’ 36-54” ½-2’ 12-15” 15-24” Notable Cultivars ‘Takahira Dake’ Dake’ ‘Takahira ‘Variegatum’ ‘Audray’, ‘Arctic’ ‘Arctic’ ‘Audray’, ‘Climax’ ‘Ivory Prince’ ‘Ivory ‘Foprtin’s Giant’ ‘Foprtin’s ‘Plena’ ‘Rosea’ ‘Bee’s Flame’ ‘Bee’s Victoria’ ‘Queen ‘Purple Showers’ ‘Nana ‘Nipon’ ‘Christmas Tree’ Tree’ ‘Christmas ‘Majestic’ ‘Alba’ ‘Superba’ ‘Alba’

Common Name K a m t s c hSedum kamtschaticum a t k a S t o n e c r o p New York Aster Aster York New belgii novi Aster Lenten Rose Rose Lenten Helleborus orientalis Lily of the Valey Lily of the Valey majalis Convallaria Lobelia Lobelia cardinalis Mexican Petunia Petunia Mexican Ruellia britoniana Mondo Grass Mondo Grass Ophiopogon Monkey Grass Grass Monkey Native Columbine Native Aquilegia canadensis

Landscape Basics: Success with Herbaceous Perennials 25 UGA Extension Bulletin 1424 - - , ev - is smaller, is smaller, V. major V. Additional Notes (periwinkle), and Moderate fertility; no drought tolerant; tolerant; no drought fertility; Moderate soils; declines in heat; drained well Drought and deer tolerant; cut flowers; cut flowers; and deer tolerant; Drought growth; aggressive fertility; low Nectar source, moderate fertility, no fertility, moderate source, Nectar soil, mites drained well tolarant, drought a problem; maybe Nectar source; drought and deer toler drought source; Nectar some species may fertility; ant;moderate reseed; Spring color; drought and deer tolerant; and deer tolerant; drought Spring color; rapidly spreads fertility; moderate Groundcover with evergreen foliage; sev foliage; with evergreen Groundcover available; are varieties variegated eral Fragrant flowers; moderate fertility; no moderate flowers; Fragrant soils; keep high organic tolerant; drought deep in do not plant in dry weather; moist clay; Nectar source, moderate fertility,do not fertility,do moderate source, Nectar with other plants; crowd Groundcover; the deepest blue-colored blue-colored the deepest Groundcover; habit; drought growth blooms; vigorous fertility; moderate and deer tolerant; rapidly; spreads Vinca minor Vinca V. minor V. groundcovers; ergreen compact; more * * * * * * * Sun

* * * Shade Partial Exposure * * * Shade Spacing Spacing (“) 8-12” 8” 2-3 bulbs in small groups 6” 12” 18” 15” 6” 12-15” 6-8”

2 Bloom Su SP/Su Su SP SP Su F Su+ SP SP Habit Groundcover Mound Mounding Spreading Groundcover Upright Mound Groundcover Groundcover Groundcover

1 Color P B,L,W,P Pu P, W P, W P, L, R P, P B B,W G Height 36-54” 15-18” 10-48” 10-14” 6-8” 24-30” 24-36” 12-14’ 3-6” 8-10” Notable Cultivars ‘Pink Bouquet’ ‘Summer Snow’ ‘Fame Blue’, Blue’, ‘Fame Blue’ ‘Buterfly ‘Purple Sensation’ ‘Purple Sensation’ ‘Siskiyou’ ‘Green Carpet’ ‘Green ‘Silveredge’ ‘America’ ‘America’ Cousins’ ‘Ann ‘Ryan’s Daisy’ ‘Ryan’s ‘My Love’ ‘Palmgold’ ‘My Love’ ‘Alba’ ‘Multiplex’ ‘Alba’ ‘Perfecta’ Common Name Obidient Plant Plant Obidient virginiana Physostegia Pincusion Flower Pincusion Flower caucasica Scabiosa Ornamental Onion and Ornamental Garlic Allium schoenoprasum Primrose Primrose speciosa Oenthera Pachysandra achysandra Peony P eonia hybrida - Chrysanthe Perennial mum Dendrathemum x morifolium Perenial Plumbago Plumbago Perenial Ceratostigma plumbaginoides Periwinkle Vinca Pigsqueak Bergenia cordifolia

UGA Extension Bulletin 1424 26 Landscape Basics: Success with Herbaceous Perennials - - S. leucantha ‘Miss Lingard’ is also ‘Miss Lingard’ S. guaranitica (Blue Sage); S. guaranitica Additional Notes P. carolina P. Drought-tolerant and attractive to butter and attractive Drought-tolerant heavy tolerant; deer source; flies; nectar deadheading is essential; fertility; produces phlox) (garden paniculata Phlox subulata P. stalks; and showy flower tall and thrift), groundcover (moss phlox, and drought-toler heat- spring bloomer, tolerates (blue phlox) divaricata P. ant; shade, and flowers; fragrant source, nectar available; and problem fertility;mildew moderate deer problem Heavy fertility; organic soils; deer tolerant; tolerant; soils; deer organic fertility; Heavy during be a problem; can mite moist; keep dormant; go they drought Nectar source; drought and deer tolerant; and deer tolerant; drought source; Nectar varies; color seedling fertility; moderate colonizes; Nectar source; drought and deer telerant; and deer telerant; drought source; Nectar can be invasive; fertility; low Moderate fertility; No drought tolerant; tolerant; No drought fertility; Moderate soils; high organic deer tolerant; Nectar source, moderate fertility, do not fertility, moderate source, Nectar with other plants; crowd (blue salvia), Salvia farinacea sage), (Mexican purple species late-blooming bushy, a tall, S. elegans in North Georgia; tender is cold all foliage; has aromatic ( sage) source; nectar butterflies; salvias attract fertility; heavy andeer tolerant; drought trimmings plants; young do not crowd help; Nectar source; trellis vine; hedge mound; vine; hedge trellis source; Nectar zone 6 or tolerant; deer fertility; heavy higher; * * * * * * * Sun

* * * Shade Partial Exposure * * * Shade Spacing Spacing (“) 8-10” 8” 4” 12” 6” 12” 10-15” 8-15” 8”

2 Bloom SP+/Su SP/Su Sp/F+ Su Su SP Su/F Su/F Su Habit Upright Upright Mounding Upright Spreading Upright Upright Upright Vine

1 Color L,P all Pu, W Y P W L W,B,R,L W Height 24-36” 22-40” 4-9” 36-48” 12-15” 15-18” 26-40” 24-54” 6-8’ Notable Cultivars ‘Bright Star’ ‘Bright ‘Magnus’ ‘The King’, White’ ‘Peacock ‘Autropurpurea’ ‘Maid of Orleans’ Beauty’‘Primrose ‘Candycane’ ‘Polaris’ ‘Polaris’ ‘Candycane’ ‘ Flame’ ‘Variegata’ ‘Blue Mist’ ‘Blue Spire’ Blue Queen’ ‘Indigo’ Blue Queen’ ‘Indigo’ ‘Rubicundra’ ‘Hatsuyuki’ Common Name Purple Coneflower Purple Coneflower purpurea Echinacea paniculata Phlox Purple Purple Oxalis regnellii Oxalis Red Hot Poker Plant Plant Hot Poker Red uvaria Kniphofia Ridgid Verbena Ridgid Verbena rigida Verbena Rooftop Iris Rooftop Perovskia Perovskia Russian Sage atriplicifolia Salvia Salvia Summer Jasmine Trachelospermum asiaticum Summer Phlox Summer Phlox

Landscape Basics: Success with Herbaceous Perennials 27 UGA Extension Bulletin 1424 - - - - - V. repens is V. (lavender cot (lavender , Rose verbena, and V. verbena, , Rose (green lavender cotton); cotton); lavender (green Additional Notes S. virens a very low-growing mat-forming type with mat-forming low-growing a very mod - source; nectar foliage; evergreen dead - tolerant; drought fertility,no erate heading is required; Santolina chaemaecyparius Santolina and ton) and salt spray drought foliage; aromatic prune fertilization; excess avoid tolerant; flowering; after Native vine, nectar source; drought and drought source; vine, nectar Native to cut back fertility; low deer resistant; each winter thumb wood Heat- and drought-tolerant; deer tolerant; deer tolerant; and drought-tolerant; Heat- char colors, of many foliage succulent flowers silver; purple, variegated, treuse, ground are species most also attractive; covers; Excellent cut flower; spring color; no spring cut flower; Excellent moderate deer tolerant, tolerant; drought well overfertilized; legy if gets fertility; soils; drained Nectar source; fragrant flowers; drought drought flowers; fragrant source; Nectar fertility; moderate deer tolerant; tolerant; is there look good, trimming to requires form single and double flower Verbena canadensis Verbena low-growing, , Moss verbena; tenuisecta drought-toler and floriferous; spreading nectar to butterflies; and attractive ant moder and deer tolerant; source;drought be a may reseed; mites may fertility; ate problem; , Speedwell, has varieties has varieties , Speedwell, spicata Veronica 1’ and 2’; between with height * * * * * * Sun *

* Shade Partial Exposure * Shade * Spacing Spacing (“) 15-18” 24” 8-10” 8” 12” 8-12” 18-30”

2 Bloom Su Su+/F SP/F Su/Su SP+/-F SP/F Su/F Habit Mounding Vine Spreading Upright Spreading Upright Upright Upright Spreading

1 Color Y W W,P,R W R,P,W W,B,L B,W Height 1½’ 10-12’ 18-30” 18-24” 12-18” 36-48” 1”-2’ Notable Cultivars ‘Nana’ ‘Pretty Pink’ ‘Nana’ ‘Pretty ‘Autumn Joy’ ‘Autumn ‘Alaska’ ‘Everest’ ‘Alaska’ ‘Alba’ ‘Carnea’ ‘Alba’ ‘Finesse’ ‘Lillipop’ ‘Icicle’, ‘Icicle’, Blue’ Border ‘Sunny - Common Name Santolina Santolina chamaecypa Santolina rissus Summer Sweet Summer Sweet virginiana Sedum Sedum Shasta Daisy Daisy Shasta Chrysanthemum superbum Soapwort Soapwort S aponaria ocymoides South American Verbena Verbena South American bonariensis Verbena Speedwell Speedwell alpina Veronica

UGA Extension Bulletin 1424 28 Landscape Basics: Success with Herbaceous Perennials - Additional Notes Groundcover with aromatic foliage; white white foliage; with aromatic Groundcover available; are varieties or gold-variegated No drought tolerant; deer tolerant; mod - deer tolerant; tolerant; No drought can be a problem; mites fertility; erate deadheading required; Full sun if moist; Heavy fertility; no fertility; Heavy Full sun if moist; declines deer tolerant; tolerant; drought in heat; Nectar source; heavy fertility; deer toler deer fertility; heavy source; Nectar in summer heat; and fertilize water ant; trim when leggy; Drought-tolerant; variegated form also form variegated Drought-tolerant; in sandy soils; thrives available; Nectar source; spring bloom; low fertility; fertility; spring bloom; low source; Nectar soils; high organic tolerant; no drought Easy to grow; heat- and drought-tolerant; and drought-tolerant; heat- grow; to Easy soil; moderate drained source;well nectar fertility; Nectar source; drought and deer tolerant; and deer tolerant; drought source; Nectar huge; fertility; moderate Fragrant blooms; declines in heat; Fragrant Hardy to zone 7; requires irrigation; heavy heavy irrigation; 7; requires zone to Hardy in mulch heavily tolerant; deer fertility; winter; Nectar source; drought and deer tolerant; and deer tolerant; drought source; Nectar wood @ to thumb trim fertility; moderate after; year & every 3years Nectar source; drought tolerant; heavy heavy tolerant; drought source; Nectar can be a soils; mites well drained fertility; problem; * * * * * * * * * Sun *

* * * * Shade Partial Exposure * * Shade Spacing Spacing (“) 6-12” 8-12” 10” 8-12” 18” 8” 12” 24” 6-8” 12” 12” 8-10”

2 Bloom Su SP/-Su SP SP/F Su Su Su Su+/F SP+/-Su Su+/F Su SP Habit Groundcover Mounding Upright Groundcover Mounding Upright Upright Upright Upright Upright Vine Groundcover

1 Color B,L Y B, L Pu Y B, W, P W, B, B Y W,P,R,L B, Pu B, R B, P Height 3-6” 18-28” 15-25” 5-8” 6-12” 12-14” 20-25” 72-96” 1-2’ 48-60” 8-10’ 3-6” Notable Cultivars ‘Elfin’ Blush’ ‘Autumn Sun’ ‘Baby ‘Bluestone’ ‘Isis’ ‘Bluestone’ Weguelin’ ‘J.C. ‘Homestead Purple’ ‘Homestead ‘Little Sundial’ ‘Sungold’ ‘Hidcote’ ‘Sungold’ ‘Alba’ ‘Rubra’ ‘Alba’ ‘Blue Danube’ ‘Capenoch Star’ Dorica’ ‘Corona ‘Blood Red’ ‘Blood Red’ ‘Homeland’ ‘Athens Blue’ ‘Athens ‘Autropurpurea’ ‘Blue Hills’ ‘Coushion Pink’

Common Name Spiderwort Spiderwort virginiana Tradascantia Tickseed Tickseed grandiflora Coreopsis Verbena Verbena canadensis Verbena St. John’s Wort Wort St. John’s Hypericum Virginia Blue Bells Virginia virginica Martensia Stoke’s Aster Stoke’s laevis Stokesia Swamp Sunflower Sunflower Swamp angustifolius Helianthus Sweet William Sweet barbatus Dianthus T i b o u cTibouchina grandiflora h i n a A t h e n s B l u e Trumpet Vine Trumpet radicans Campsis Thrift subulata Pholox Thyme Thyme

Landscape Basics: Success with Herbaceous Perennials 29 UGA Extension Bulletin 1424 Exposure Spacing Partial Common Name Notable Cultivars Height Color1 Habit Bloom2 (“) Shade Shade Sun Additional Notes Nectar source; drought tolerant; trim no Whirling Butterflies ‘Geyser White’, 24-36” W Upright Su/F 8” * more than the top 1/2 of the spent flower Gaura lindheimerii ‘Snow Fountain’ stalk; Woodland Phlox ‘Blue Ridge’ Nectar source; spring color; moderate fer- 12-18” B, P Spreading SP 12” * * * Phlox stolonifera ‘Pink Ridge’ tility;keep moist; mites can be a problem; Yellow Baptisia Drought and deer tolerant;moderate fertil- 26-45” Y Upright Su 8-10” * Baptisia tinctoria ity; comes up late; mark site;

1 Color: G = gold, W = white, P = pink, Y = yellow, R = red, B = blue, O = orange, L = lavender, S = silver, Gr = grey, Pu = purple, all = all colors, - = indicates absence of a single color, all others represented.

2 Bloom: SP = spring, Su = summer, F = fall, W = winter, - = early, + = late, / = range of bloom. Stipes Publishing, IL. Culture, and Garden Attributes. 3rd Ed. A.Armitage. 2008. Herbaceous Perennial Plants: ATreatise on their Identification, Books University of MarylandExtension. “Total Plant Management of Herbaceous Perennials,” 359. Bulletin Other Extensionpublications “Care of Ornamental Plants Landscape,” inthe 1065 Bulletin “Repellents and Wildlife Damage Control,” Circular 1021 “Deer-Tolerant Ornamental Plants,” Circular 985 Circular 889-1 “Using Milorganite White-Tailed to Repel from Deer Perennials,” 987-4 “Native Plants for Part Georgia: IV. Grasses and Sedges,” Bulletin “Native Plants for Part Georgia: III.Wildflowers,” 987-3 Bulletin “Native Plants for Part Georgia: II.Ferns,” 987-2. Bulletin Organic One,” Circular 853. “How to Convert an Inorganic Recommendation Fertilizer to an UGA Extensionpublications Additional Resources color, nationalorigin,age,genderor disability. cational programs,assistanceandmaterials toallpeoplewithoutregardrace, of andcountiesofthestatecooperating.UGA Extensionoffers edu- The UniversityofGeorgia andFort Valley StateUniversity, theU.S.Department Bulletin 1424 The Universityof Georgiaiscommittedtoprinciples ofequalopportunity and affirmative action. December 2013