Well established clematis vines are breathtaking when in bloom. Large showy flowers can adorn a mailbox, fence or lamp post and bring it alive. Hundreds of cultivars are available in a cornucopia of colors, sizes and blooming seasons. The problem is that too often gardeners can’t get those fussy vines to live past their second season.
Clematis has interesting and rather unique growth requirements. Plants require bright sunlight to flower, but they must have cool shaded roots to grow. Usually this is accomplished by some type of companion crop in combination with mulching.
Even with proper planning it’s often difficult to nurse these vines to maturity. Once there, clematis often outlives the gardener. Fertilization is helpful but never during the blooming season.
Since we’re talking about a vine, we must consider some type of support. Otherwise a sprawling unkempt eyesore will develop. That is unless the plant dies, which is likely. Clematis needs string, fishing line or wire to begin its climb to a permanent support.
Soil should be well drained. High organic matter is helpful as clematis dry out easily. Well drained and moist sounds like a contradiction in terms, but that condition is necessary for healthy growrh. Acid soils must be amended to near neutral pH.
Once plants become established, pruning is necessary. Usually vines are pruned in late winter to early spring. Waiting too long will delay flowering. Some types can be cut to the ground in early spring, while others must be pruned more sparingly. Experience with various cultivars is the best teacher.
Slugs are a common pest of clematis. This is often exacerbated by planting hosta to shade clematis roots. Earwigs attack flower buds and disfigure the blooms. Grazers like deer and rabbits like clematis foliage and can be a major problem in some locales.
Their primary disease is Clematis wilt caused by several different fungi. Spotting leaf margins, browning leaf blades, wilting and leaf drop are dominant symptoms. Older lower foliage usually is most affected.
Proper pruning, fertilization and general environmental conditions like moisture and light help reduce the problem. If wilt occurs on your plant, cut it to the node below where the infection or wound appears. If no leaves are evident a couple inches should be sufficient.
Healthy flowering clematis vines are alluring. Many folks like to use various flowers as decoration on cakes and salads. Clematis should not be used since its flowers are poisonous. Skin irritation, vomiting and diarrhea are probably the worst problems for humans. Toxicity isn’t severe. I have read problems might be greater in dogs, cats and horses.
Clematis isn’t edible, but I view some literature with a grain of salt. A University of California toxic plant site lists choke cherry as highly toxic. I grew up eating them both fresh and in homemade jelly with never an adverse effect. I never consumed the poisonous seeds. I never plan to eat clematis.
Still, individual experience must be the teacher. Consume any new foods, especially nontraditional ones, in small quantities initially.
Ted Manzer teaches agriculture at Northeastern High School.