G roundcovers & Perennials G roundcove rs & Perennials G roundcove rs & Perennials G a rdening green Many of the characteristics that make a G roundcove rs plant a good choice for the garden may Instead of periwinkle, wild ginger also make it a successful invader: & Perennials DON’T PLAN T: English ivy or Algerian ivy, (Asarum caudatum) Don’t California is a gardener’s dream. Our mild climate allows A California native, this Garden Plants Invasive Plants us to have fantastic gardens, showcasing a wide variety periwinkle evergreen groundcover has Easy to propagate Broad germination T RY THESE VARIETIES: of ornamental plants from DON’T PLAN T: (Vinca major) heart-shaped leaves and unusual Establish rapidly Colonizer all around the world. This aggressive grower pachysandra maroon flowers. Mature early Mature early iceplant or Hottentot fig Howitt, © 1999 Beatrice F. Calif. Academy of Sciences has trailing stems that Plant a But sometimes, our Abundant flowers Prolific seeds (Carpobrotus edulis) (Pachysandra terminalis) root wherever they touch bear’s foot hellebore garden plants “jump the Pest / disease tolerant Few natural predators Small mammals can carry seeds of Grows more slowly than Vinca the soil. This ability to and Hedera, but has a crisp, (Helleborus foetidus) fence” and invade natural iceplant from landscape settings to resprout from stem areas. These invasive nearby coastal dunes and other neat growth form. New foliage Unusual foliage and delicate, Invasive plants are by nature a regional problem. A plant fragments enables is bright green, changing to complex flowers. The intriguing

plants can become serious sensitive areas. The vigorous Alfred Brousseau, © 1995 Br. College Saint Mary’s that jumps out of the garden in one climate and habitat periwinkle to spread Pest! wildland weeds that groundcover forms impenetrable mats dark green with age. Variegated pale green and purple flowers rapidly in shady creeks and drainages, smothering the type may behave perfectly in another. The problem plants Courtesy Missouri Botanical Garden threaten California’s that compete directly with native cultivars are available. often have a pleasant fragrance. listed here have escaped from gardens throughout the native plant community. biodiversity and economy. vegetation, including several rare and Central Coast. Serbian bellflower Corsican hellebore threatened plants along the coast. © 1998 Charles Webber California Academy of Sciences Give them an inch Vinca has escaped from (Campanula poscharskyana) or Lenten rose

Over half of the plants San Luis Obispo County Farm Bureau Courtesy Mark Souder, How to use this brochure: landscaped areas into wildland Produces a profusion of lilac-blue, Courtesy Missouri Botanical Garden currently damaging Instead of iceplant or Hot tentot fig, (H. argutifolius or H. orientalis) French broom invades This brochure suggests safe alternatives for these plants. habitats throughout the Central star-shaped flowers spring to fall. and they’ll ta ke California’s wildlands were Besides bear’s foot hellebore, there are several other parts of SLO County When you are buying new plants, consider these Coast, and due to its nursery Grows quickly and easily, but could originally introduced for T RY THESE VARIETIES: perennial hellebore species available that can grow well alternatives, or ask your local nursery for other non- availability there is the overwhelm a carefully manicured in Central Coast gardens. an acre... landscaping purposes. Garden escapes like pampasgrass hardy iceplant potential for increasing garden.

invasive plants. If one of the invasive plants is already in Courtesy Missouri Botanical Garden

and French broom may have desirable characteristics in a Courtesy Ken Owen, Channel Islands Restoration your yard, especially if you live near wildlands, you may (Delosperma cooperi) problems associated with this Bergenia or winter saxifrage garden setting, but outside the garden these plants want to remove it and replace it with a recommended A non-invasive iceplant with commonly used groundcover. In the adjacent photo, ivory star jasmine or asian jasmine (Bergenia cordifolia and hybrids) displace native species and alter natural processes. alternative. Think about why you might plant one of the smaller, succulent leaves and volunteers hand remove vinca on habitat-rich Santa Cruz (Trachelospermum asiaticum) An evergreen groundcover, with large, dark green leaves, problem plants in the first place. Is it just for the way it brilliant violet-pink flowers May Island in Santa Barbara County. Vinca has invaded Has glossy, dark green leaves and clusters of bright, deep pink flowers. Some of these plants looks? If so, finding a replacement is often easy—some through October. Salt tolerant. several riparian areas and oak woodlands on the island, and pale yellow, pinwheel-

show weedy tendencies David Fenwick © 2003 The African Garden of the alternatives listed here are selected especially for having escaped from a horticultural planting years ago. shaped flowers with a jasmine in the garden as well. their similar appearance. Or beach strawberry scent. For example, English ivy maybe you need a plant to fill a Other Potential Plant Pests can take over a yard and Full sun or wood strawberry English ivy or Algerian ivy functional role, such as a damage buildings and Part shade (Fragaria chiloensis or Fragaria vesca ssp. californica) (Hedera helix, H. caneriensis) evergreen currant The plant pests detailed in this brochure represent those groundcover that grows well in a fences. Likewise, when Full shade This perennial, evergreen groundcover When birds carry the seeds of these popular plants into (Ribes viburnifolium) invaders that have escaped in our area and are also shady place, or a border plant commonly found in nurseries. There are many other birds drop seeds near a Drought tolerant forms a lush, low-growing mat. Leaves wildlands, ivys can smother A low-growing evergreen shrub with fragrant, dark-green that likes full sun. Alternatives troublesome weeds found along the Central Coast that stream, English ivy can Low water are dark-green and glossy with a red forest trees and understory leaves. Can tolerate full sun along the coast but needs

Courtesy John Randall, The Nature Conservancy were intentionally introduced into this area. In most cases,

Photo by Brianna Richardson, 2003 listed here thrive in the same take over native tint in winter. Mow or cut back the plants by completely shading partial shade in the hotter, inland areas. Once estab- English ivy destroys forest environments as problem plants Moderate water it was years or even decades before these plants were vegetation and degrade plants in early spring to encourage them, which also prevents lished, evergreen currant does not need irrigation and is A dense stand of pampasgrass (Cortaderia selloana), understory vegetation while offering added benefits Regular water recognized as causing serious economic and ecological wildlife habitat. new growth. Chris Morris, SLO County Department of Agriculture regeneration of new tree and an excellent choice for growing under native oaks where damage to our local natural resources. a garden plant that has invaded California wildlands such as attracting wildlife. Many High water shrub seedlings. Ivy also supplemental watering is discouraged. of these alternatives are readily California native The list below includes additional garden plants that have Gardeners don’t plant invasive species intentionally. Like germander harbors pests, such as rats available, though others may be escaped into our local rangelands and wildlands. Although Deer resistant (Teucrium chamaedrys, or T. x lucidrys) Courtesy Missouri Botanical Garden Suggested alternatives for invasive garden plants. other Californians, gardeners have a deep respect for our and snails. easiest to find in specialty or Fire resistant This plant can be sheared into a neat groundcover or giant alumroot or coral bells these are not often sold in nurseries any longer, it is state’s rich natural heritage. The good news is that most important to be aware of them and avoid planting them More information available at www.cal-ipc.org native plant nurseries. allowed to grow to full height (about one foot), and (Heuchera maxima and hybrids) garden plants behave perfectly well in their intended Ornamental ivy has already whenever possible. You may also consider removing them roles. By choosing suitable replacements for the few produces lavender flowers in the spring. Compact escaped in many local if they are already growing on your own property, especially problem plants, we can save ourselves trouble and Both native and non-native plants have been recommended as cultivars are available. areas, causing severe This evergreen groundcover has if your land is adjacent to a natural or open space area. alternatives in this brochure. Care has been taken to ensure that expense in our garden and help to protect the natural problems for our native heart-shaped leaves and tiny, bell- none of the recommended non-natives is invasive. However, plants showy dewflower or rosea iceplant Other Invasive Garden Plants: Arundo/Giant Reed Central Coast Version California landscape at the same time. can adapt over time, and there is no guarantee that some of these habitats. In this photo, shaped, pink and white flowers that (Drosanthemum floribundum) (Arundo donax), Cape Ivy (Delairea odorata), Fennel Cove ring San Luis Obispo plants will not themselves become pests in the future. If you notice English ivy invades Arroyo hang gracefully from thin stalks. (Foeniculum vulgare), Tree-of-Heaven (Ailanthus one of these alternatives invading natural areas, notify Cal-IPC. Pay A succulent with silver-gray leaves and an abundance of Grande Creek, smothering There are many hybrid varieties & Santa Barbara Counties close attention to plant names, since a few of our recommended altissima), and Salt Cedar/Tamarisk (Tamarix spp.). pink flowers. Requires little or no water, especially along trees and crowding out available with a wide range of leaf plants may have invasive relatives—even in the same genus. the coast. Tolerates some salt spray. vegetation along the banks. Courtesy El Nativo Growers, Inc. colors and textures. Marc Lea, SLO County Department of Agriculture Shrubs Shrubs Shrubs O rnamental Grasses Don’t Plant a Pest! Shrubs O rnamental Grasses Instead of broom, Jerusalem sage pineapple guava Instead of pampasgrass, Central Coast Version (Phlomis fruticosa) (Feijoa sellowiana) DON’T PLAN T: jubatagrass or green fountain grass, T RY THESE VARIETIES: Has bright yellow flowers and This evergreen shrub has Produced by DON’T PLAN T: T RY THESE VARIETIES: gray-green, textured leaves. scarlet and white flowers, as pampasgrass or jubatagrass San Luis Obispo County Foundation forsythia delicious as they are beautiful, and © Joy Creek Nursery (Cortaderia selloana and Cortaderia jubata) deer grass (Muhlenbergia rigens) for Agriculture Awareness broom (Forsythia x intermedia) waxy blue-green fruits with a minty Both of these South American This large perennial California (805) 543-3654 (Scotch, French, Spanish, Portuguese) (Cytisus scoparius, Genista monspessulana, Spartium Often the first plant to bloom in bush poppy pineapple flavor. It is easily shaped plants, originally introduced into native has dense clusters of San Luis Obispo County junceum, Cytisus striatus) spring, forsythia produces an (Dendromecon rigida) into a small tree. California through the nursery trade, narrow, bright green leaf blades Department of Agriculture astounding display of bright A native California shrub that is not yet widely available have escaped cultivation and and tall, slender flower stalks. Bold (805) 781-5910 www.sloag.org yellow flowers. Dozens of cultivars in nurseries. Very drought tolerant once established, invaded wildlands along the Central enough to be used as a focal point

These four brooms have © Monrovia © Monrovia are available. Grows quickly. bush poppies will produce showy yellow flowers from Coast. Jubatagrass is the more of the garden, it also partners well invaded over one million spring through early summer. Needs pruning to maintain acres in California. The strawberry tree severe problem in San Luis Obispo with other perennials, flowers and FOR MORE INFORMATION ABOUT winter jasmine compact, landscape friendly form. County, while both pampasgrass shrubs. Once established, deer flowers produce thousands (Jasminum nudiflorum) (Arbutus unedo) INVASIVE PLANTS, VISIT: of seeds that build up in the A gorgeous evergreen tree and jubatagrass have invaded parts Courtesy Brianna Richardson, 2003 grass is extremely drought tolerant Arching green stems and bright shrub hypericum of Santa Barbara County. pampasgrass and fits in perfectly with a water- San Luis Obispo County Weed Management Area soil over time, creating available in compact, shrub-like

yellow flowers that bloom in Marc Lea, SLO County Department of Agriculture dense thickets that can (Hypericum ‘Rowallane’) conscious California garden. www.sloag.org/wma winter characterize this varieties that are easy to grow. Pampasgrass is still widely available in nurseries, while decimate entire plant and This shrub produces bright yellow flowers through Santa Barbara County Weed Management Area deciduous shrub. It produces masses of beautiful jubatagrass is rarely sold locally but Lindheimer’s muhly grass animal communities. summer and fall. Tolerates poor soil. white flowers, and textured, www.countyofsb.org/agcomm/wma may be found advertised in various (Muhlenbergia lindheimeri) Besides crowding out native strawberry-like fruits. California Invasive Plant Council seed and flower catalogs. Although This large, dependable, and showy ornamental grass

plants and damaging wildlife Park Arboretum Courtesy Washington female pampasgrass plants can be has blue-gray foliage and flower- www.cal-ipc.org habitat, French broom is DON’T PLAN T: grown without escaping cultivation, it

© Monrovia ing spikes in the fall and winter. The Nature Conservancy highly flammable and Lady Banks’ rose (Rosa banksiae) cotoneaster is very difficult to distinguish between Good in poor soils, it grows up http://tncweeds.ucdavis.edu creates an increased fire risk Readily available in local (Cotoneaster lacteus, C. pannosus) male and female plants or even to five feet tall. Works well as a in local canyons and forests. California Department of Food and Agriculture nurseries and easy to grow, Birds have spread the berries sandankwa viburnum between jubatagrass and pampasgrass. specimen plant or massed into

www.cdfa.ca.gov San Luis Obispo County Farm Bureau Courtesy Mark Souder,

It is best to avoid using any of the Courtesy Bluestem Nursery, www.bluestem.com Lady Banks’ rose is a hearty County and seeds of these specimen (Viburnum suspensum) an attractive border. National Invasive Species Council Of the four invasive brooms, both Spanish and French climber with few pest problems. shrubs to many different habitat This evergreen shrub SLO County Farm Bureau Mark Souder, Cortaderia species, especially in our jubatagrass New Zealand flax (Phormium tenax) www.invasivespecies.gov broom have already escaped in San Luis Obispo County, It has glossy evergreen leaves, types. With their rapid growth produces tight clusters of small, vulnerable coastal areas. the stems are nearly thornless, and competitive roots, Although not a true grass, New FOR MORE INFORMATION ABOUT with French broom becoming an emerging local problem. waxy, pinkish-white flowers that Both grasses have large characteristic flower plumes, and it produces large clusters of cotoneasters displace native give way to bright red berries. Zealand flax fills a similar function CALIFORNIA NATIVE PLANTS, VISIT: French broom is found in shady canyons throughout the Karen Lowerison, SLO Department of Agriculture sharp leaf blades, and can form large clumps over five

small, yellow blooms each plants and animals. © Monrovia in the landscape as many of the county and is most widespread in the Cambria area, Several compact varieties are feet tall. The massive size of each pampasgrass plant California Native Plant Society where it often grows under the pine forest canopy (See spring. Can be trained on an arbor or fence or used to available. There are many other popular ornamental grasses. SLO County Chapter: www.cnps-slo.org cover banks and other large areas. Instead of cotoneaste r, reduces wildlife habitat, limits recreational opportunities, Individual plants are large, hardy, map below for details). viburnum species available, and creates a serious fire hazard. Individual plants can Channel Islands Chapter: www.cnpsci.org including several additional and require minimal care while Japanese kerria T RY THESE VARIETIES: produce thousands of tiny seed which can be carried by Chris Morris, SLO County Department of Agriculture offering a bold point of interest to Broom Infestations within SLO County evergreen species grown for wind for miles. This edition of the “Don’t Plant a Pest” brochure was adapted from (Kerria japonica) both their foliage and flowers, any garden. Numerous varieties and hybrids are now the original version developed for the San Francisco Bay Area by toyon Golden yellow flowers first appear in such as V. rigidum (Canary green fountain grass available, coming in a range of sizes and leaf colors, Cal-IPC with participation from the following organizations: BMP (Heteromeles arbutifolia and cultivars)

© Courtesy Mark Shelby, University of Florida-IFAS© Courtesy Mark Shelby, Extension including many with striking stripes of red, yellow and green. Ecosciences, California Department of Food and Agriculture, California spring on this graceful shrub, and Island viburnum) and V. tinus (Pennisetum setaceum) Native Plant Society, Contra Costa County Department of Agriculture, This California native is an evergreen shrub that Daar/IPM Consulting Group, East Bay Municipal Utility District, Faultline continue into summer. Stems remain (Laurustinus). This perennial grass Cape thatching reed Magazine, Golden Gate National Recreation Area, Marin County produces delicate white flowers and large clusters of © Monrovia bright green in winter after leaves fall. produces large amounts of Department of Agriculture, Monrovia Nursery Company, The Nature brilliant red berries that birds love. (Chondropetalum tectorum) Conservancy, Point Reyes National Seashore, Return of the Natives calamondin orange seed that are spread by This decorative, “grass-like” plant produces attractive Restoration Education Project, Santa Clara Weed Management Area, Citrus mitis Citrofortunella microcarpa vehicles, animals, and wind Sloat Garden Centers, Strybing Arboretum, Suncrest Nursery, UC golden currant ( or x ) flowers that are ideal in cut flower arrangements. Grows Cooperative Extension, UC Davis Arboretum, and UC Botanical Garden. (Ribes aureum) A natural hybrid between the tangerine and kumquat. into natural areas. Fountain three to four feet tall. A California native, this shrub Evergreen with shiny green leaves, and small, fragrant, grass is still widely available has a profusion of bright waxy white flowers followed by long-lasting, bright orange in nurseries, and is spreading Chris Morris, SLO County Department of Agriculture San Diego sedge (Carex spissa) yellow flowers that turn into fruits that make great marmalade. rapidly throughout California. Dense infestations can This large sedge has a form similar to that of an Cal-IPC Spanish Broom edible berries suitable for crowd out native species, as well as raise fuel loads ornamental grass. Produces gray leaves to five feet tall California Invasive Plant Council jams and jellies. Birds and increasing fire frequency and intensity. and yellow, grass-like flowers in the spring. French Broom Dr. Robert Thomas and Margaret Orr Dr. © 1999 Calif. Academy of Sciences www.cal-ipc.org butterflies love this plant. J. E. (Jed) and Bonnie McClellan © 1999 California Academy of Sciences