Clematis require alkaline soil. For most areas of Connecticut, that means adding lime, but a soil test is the only way to determine if you need to add lime and how much. They also need plenty of moisture and they like to grow into the sun but keep their roots cool. This can be accomplished by mulching or by placing other plants to grow around the base of the vines and shade their roots.
Stem rot, also called Clematis wilt, is the most common problem of clematis. The plant will appear to be wilting without evidence of mechanical damage (i.e. severed stems). To prevent this, use coal ashes, a zinc collar, or sand in an inverted flower pot (the plant grows up through the drainage hole) at the base of the plant. If stem rot does occur, do not plant another clematis in the same spot. Since it happens in large flowering varieties, plant small flowering types to eliminate the possibility, ex. Clematis viticella.
There are three basic types of Clematis:
How do I know what kind of Clematis I have?
Inevitably, the next question is “How do I know which kind I have?” If you know the name, you can look it up online or in a good reference book. If you don’t know the name, you must be observant. For this year, don’t do any drastic pruning. Just watch the plant and record when it blooms. Look closely at where the flowers are coming from. Do they sprout from older looking, woody stems? Or do they come from fresh, young growth? By careful observation, you should be able to figure out which kind of Clematis you have and thus how to prune it.
Clematis blooming on last year’s wood: (Type 1)
C. alpina varieties
C. macropetala varieties
C. montana varieties
Clematis blooming on both last year and this year’s wood (Type 2)
C. florida ‘Sieboldii’
‘Anna Louise’ ‘Lady Betty Balfour’
‘Arctic Queen’ ‘Miss Bateman’
‘Bees’ Jubilee’ ‘Multi Blue’
‘Belle of Woking’ ‘Nelly Moser’
‘Crystal Fountain’ ‘Parisienne’
‘Diana’s Delight’ ‘Rebecca’
‘Dr. Ruppel’ ‘Rosemoor’
‘Duchess of Edinburgh’ ‘The President’
‘Elsa Späth’ ‘Versailles’
‘General Sikorski’ ‘Vyvyan ‘Pennel’
‘Henryi’ ‘Will Goodwin’
Clematis blooming on this year’s wood (Type 3)
C. languinosa varieties
C. viticella varieties
‘Comtesse de Bouchard’
‘Ville de Lyon’
In an effort to provide horticultural information, these educational documents are written by Nancy DuBrule-Clemente and are the property of Natureworks Horticultural Services, LLC. You are granted permission to print/photocopy this educational information free of charge as long as you clearly show that these are Natureworks documents.