When to prune Clematis
New wood or old wood variety?
How and when you prune
clematis depends on when it blooms and its growth habit.
Horticulturists divide clematis into three groups, based on their
time of bloom.
flower on the current year's growth, often referred to as "blooming
on new wood."
Others flower from buds produced on last season's
growth, which is referred to as "blooming on old wood." Still others
flower on old and new wood. It is easy to look up the proper pruning
group if you know the cultivar name or species of your clematis.
Clematis pruning groups:
Group 1 or
Early-flowering species that generally bloom in April and May from
buds produced on last season's growth (old wood). They should be
pruned as soon as possible after they finish flowering. Avoid
pruning them after the end of July, so they have time to produce
next year's flower buds before winter sets in.
pruning out any dead, damaged or weak stems. Then prune out the
shoots that have flowered. You can also prune out more stems at
their point of origin to thin out the plant and maintain a good
framework of main stems that flower well within easy view. Avoid
cutting into the woody main trunks.
Group A include C. alpina, C. chrysocoma, C. macropetala and
cultivars, and C. montana and cultivars.
Group 2 or
Large-flowered hybrids such as 'Nelly Moser' that bloom in June on
short stems from last year's growth (old wood) and often flower
again in late summer on new growth (new wood). Because you do get a
few flowers after cutting the plant back so hard in the fall, it is
likely that yours falls into this category.
This group of
clematis should be pruned in February or March. Begin by removing
dead and/or weak stems. Then cut the remaining stems back to the
topmost pair of large green buds. This cut could be a few inches to
a foot or more back from the stem tips.
Plants in this
group have the tendency to become bare at the base as they mature.
You can underplant with small shrubs or perennials to help conceal
the bare stems. Alternatively, you can often force a flush of new
growth from the base by cutting the vine back to 18 inches
immediately after the flush of bloom in June.
In addition to
'Nelly Moser,' plants in this group include: 'Miss Bateman,' 'Lasurstern,'
'Duchess of Edinburgh,' 'Belle of Woking,' 'General Sikorski,' 'Mrs.
N. Thompson' and 'The President.'
Group 3 or
Late-flowering species and hybrids, including sweet autumn clematis
(C. terniflora). This group flowers on the last 2 to 3 feet
of the current season's growth (new wood). Some types begin blooming
in mid-June and continue into fall. They are easy to prune because
you do not need to maintain any old wood. In February or March, cut
each stem to a height of 1 or 2 feet. Although you will be removing
good stems and buds, this treatment keeps these vigorous growers in
bounds. In addition to Clematis terniflora, plants in this group
include: Clematis x jackmanii, C. tangutica, C. viticella, 'Duchess
of Albany,' 'Comtesse de Bouchaud,' 'Ernest Markham,' 'Lady Betty
Balfour,' 'Madame Julia Correvon,' Perle d'Azur' and 'Royal Velours.'
Vines for a
Artillery Fungus putting black spots on