For more information on gardening Supports should be at least 2/3 to 3/4 the Group 1 - Remove only dead wood in spring. please visit: ultimate height of the vine. Pergolas and Prune after bloom if needed to reduce size, https://extension.illinois.edu/global/ arbors are good choices for vines taller control growth, or make plant fuller. Prune no later horticulture Clematis: than 10 feet. Use obelisks or trellises for than the end of July. or call shorter plants. Place the support 1 foot University of Illinois Extension Knox County away from the base of the plant. Group 2 - In early spring remove any dead wood and cut back to the topmost pair of live 309-342-5108 Queen of buds. You can prune hard after first bloom if Plants can also be allowed to grow over desired. fences, rock walls, deck rails, stumps, @ThreeRiversHort the Vines lamp posts, mail boxes, or columns, or to Group 3 - Cut back in early spring before ac- sprawl as a ground cover. tive growth begins. Prune just above the lowest living bud (usually 6-18 inches). @three_rivers_hort Care & Maintenance Potential Problems @ILExtensionHKMW Renew mulch in spring. Water during dry periods. Clematis is generally rather trouble-free. The biggest problem is clematis wilt. Plants may also Developed and Written by Although some clematis in a good location be bothered by other diseases and pests, Knox County Master Gardeners may do fine without any fertilization, you environmental issues, or poor location of plant. University of Illinois Extension can use a balanced fertilizer once a year. September 2018 Fertilize after first bloom for groups 1 and 2, Clematis wilt is caused by a fungus. It blocks the and after pruning in spring for group 3. stem and prevents water and nutrients Heavy bloomers or especially vigorous from reaching the upper plant, resulting in growers may need more but be careful not stem wilt and death. No varieties are immune to overfertilize. Don’t fertilize when in bud or but some are more resistant than others. bloom. Large-flowered varieties and young plants Other information brochures can be found are the most susceptible. online at https://extension.illinois.edu/ Pruning Clematis hkmw/gardening-and-nature-brochures Clematis wilt is often not fatal to the entire Prune to encourage new blooms, remove plant. Prune the affected stems 1 to 2 inches below the infected part and destroy the clip- dead wood, direct growth, and control University of Illinois ~U.S. Department of pings. Planting deep helps the plant recover if it size. Wait until after growth resumes in Agriculture ~ Local Extension Councils Garden Tips does become infected. Fungicides can be used spring when removing dead wood. Cooperating Deadheading spring bloomers may en- as a preventative but will not help once the plant is infected. from courage later rebloom of some varieties. University of Illinois Extension provides equal opportunities in programs and employment. Old or overgrown clematis can be rejuve- A key to protecting plants from wilt and other nated by cutting the plant back to just problems is reducing stress by planting in the Knox County U N I V E R S I T Y O F I L L I N O I S above the lowest bud in early spring. proper location and providing the right growing Group 1 plants will not bloom that sea- conditions. Provide consistent moisture and E X T E N S I O N Master Gardeners son, however. good air circulation and keep mulch away from H E N D E R S O N , K N O X , stems. Try to prevent stem injury - the fungus M C D O N O U G H A N D WA R R E N Timing and technique of pruning varies by needs a wound to enter the plant. C O U N T I E S group. Read your tag or plant description (or observe your plant) to determine which Sanitation is also important. Remove all plant Knox County Office group your plant belongs to. debris in fall and destroy if there have been any 180 S. Soangetaha Rd. Suite 108 disease problems. Galesburg, IL 61401 Phone: 309-342-5108 Fax: 309-342-1768 You may have heard the saying “head in the Most authorities recommend burying the Clematis is a group of plants found in al- Clematis Class or Group sun, feet in the shade” referring to clematis. plant anywhere from 1 to 6 inches (a sug- most every area of the world, with about Most prefer cool, moist, well-drained soil with 300 species and thousands of hybrids. Class refers to whether the plant blooms on gestion of 2 to 4 inches is most common) or slightly acidic to neutral pH. Shrubby and with 2 buds below the soil surface. This The name comes from the Greek word new wood, old wood, or both, and affects herbaceous varieties may be more drought klema, meaning vine branch. Most are the probability of flowering as well as pruning helps the plant recover from top damage, tolerant. None of the clematis however like clematis wilt, or winter dieback by sending woody vines, but the genus also contains timing and technique. Class may also be wet feet, particularly in winter. herbaceous and shrubby types. referred to as pruning group, and should not up new shoots from below. It also protects be confused with terms such as Oriental the crown in cold climates and Provide good air circulation but protect from encourages branching, multiple stems, and a Clematis produces attractive flowers in a Group or Astragene Group, which are used strong winds to prevent damage to stems. variety of colors, sizes, and shapes. to classify or organize the many species and fuller plant. This is most important for large- Some have contrasting stamens or attractive crosses of clematis. flowered hybrids. If at the time of planting seedheads, which sometimes persist into Choosing a Variety there are new green shoots at the base, wait winter. Flowers may attract butterflies and Group 1 (A or no prune) - This group until they become woody before filling in with hummingbirds. Most varieties are deer and blooms on old wood in the spring, with While you may make your final choice soil. rabbit resistant. flower buds forming in the fall. These may not based on color, size, or other characteristics, reliably bloom in cold climates, as harsh always be aware of the group. Groups 2 or 3 Use a starter fertilizer and water thor- Vining types can be used as a screen, winters may cause dieback. are the best choices in Central Illinois. If oughly. Keep well-watered until estab- focal point, or even as a groundcover. choosing a Group 1 variety you will need to lished. Shorter or herbaceous types can be used in Group 2 (B or half prune) - This group provide winter protection or accept that it may borders. Use cut flowers or dried blooms on old wood in the spring and not always bloom. Cut back after planting to prevent damage to seedpods in arrangements. again on new wood in late summer or fall. If the plant, stimulate root growth, and buds are killed by winter weather you will Other considerations include hardiness, dis- encourage branching. Prune to 12 inches the Types of Clematis still get blooms later in the season. Some ease resistance, size, growth habit, and first two years (only the first year for Group varieties produce double flowers on old wood conditions where it will be planted. 1), and after that prune according to group. and single on new wood. We often think of ‘Jackmanii’ with its large Flower color, size, and form are personal To shade roots add mulch or plant ground purple blossoms or prolific sweet autumn preference. Bloom time and length vary - cover, annuals, or low-growing perennials or clematis but there is a wide variety available. Group 3 (C or hard prune) - This group blooms only on new wood with flower choose varieties so you will have blooms all shrubs around the base. Keep mulch 8 buds formed in the spring. It will bloom season. inches away from stems to help prevent Flower size varies from a diameter of less clematis wilt and other fungal diseases. than an inch to 7 to 8 inches or larger. only at the end of the stems if not pruned back hard. Some varieties start blooming in Look for stocky, healthy, vigorous, multi- Small flowered varieties are often fra- stemmed plants when purchasing. grant. Flowers can be single or double (or mid-June and continue into fall. Group 3 Supporting Clematis sometimes both on the same plant) and clematis produce reliable bloom in this area There are hundreds to choose from. Look for can hang downward or face upward. and are easiest to prune. Clematis climb by twining, using petioles or some of the more unusual varieties. You Flowers can be flat, tubular, or star, bell, or leaf stems - they cannot “grab” onto a may have to go beyond local nurseries or big lantern shaped. Some plants have surface. They may need a bit of help and Where to Plant box stores and look at specialty nurseries clusters of small flowers. Flower color guidance, especially in the beginning, and do or online. can be white, yellow, pink, red, purple, Preferred conditions may vary by species best with thin supports. If the support is lavender, blue, or bicolor. Bloom time and and cultivar. Clematis can be long-lived so greater than 3/4 inch in diameter add twine, length varies with the group (see below) choose the location carefully. Research How to Plant heavy knotted fishing line, wire screening, and individual variety. your particular variety. Information should be nylon netting, or wooden lathe to help vines available on plant tags or in catalogs. Spring is the best time to plant. You can climb. A few, such as C. x durrandii, have Plant height can range from 2 to 30 feet. also plant in early fall or summer if the plant is long stems but are non-twining and may Large-flowered hybrids are usually 8 to 12 Most varieties need at least 6 hours of sun but kept well-watered. need to be tied to the support or just feet. Hardiness as well as growth habit some tolerate (or prefer) more shade. Too allowed to scramble hori-zontally. and rate vary with species or variety. much sun, especially hot late afternoon Before planting dig a large hole (about 2 sun, may cause some colors (such as large feet deep and 2 to 3 feet wide). Add 1/3 by red and blue or bi-color) to fade. volume compost or well-rotted manure and mix well.