Clematis is one of the flowering vines better adapted for higher
altitudes. The best known flower colors are the cool shades of purple,
blue, pink and white. Hotter shades of red and yellow are also available.
Flower shapes range from large, eight-inch hybrids to the dainty bells
and honeysuckle blooms of autumn clematis.
In Colorado, planting clematis in the spring is generally more successful
than fall planting. Vines do best in full sun and bloom poorly in more
than a half-day of shade. A trellis or other support is helpful in windy
periods.
Plant clematis in a soil that drains well and is amended with organic
matter such as compost. The crown, the part of the plant where the stem
and roots meet, should be about two inches below the soil. Keep plant roots
moist and cool by using mulch. However, clematis roots do poorly when the
soil around them is water-logged.
Supply four to six inches of an organic mulch (compost, wood chips)
in the spring over the plant's root system.
Prune clematis to promote flowering. There are two different kinds of
clematis and you need to determine which kind you have before you prune.
Woody-stemmed types like the Montanas bloom early on last year's stems.
Prune plants after flowering to remove deadwood.
Large-flowered Henryi and Elsa Spaeth hybrid types also should be pruned
this way. Types that bloom on the current year's growth should be cut back
in early spring to the first pair of healthy buds. These include Clematis
x jackmanii and Clematis 'Ernest Markham' hybrids among others.
Well-established clematis will bloom for generations.
Large flowered clematis varieties usually have a great deal of dead wood
each spring; small flowered kinds, proportionately less. During
the growing season fertilize the plants with super- phosphate or
ground bone, and potash in any form, but use sparingly such nitrogenous
plant food as manures, nitrate of soda and sulphate of ammonia.
When winter sets in mulch with strawy litter or other loose material
to prevent heaving and settling of the ground due to alternate freezing
and thawing.
When spring comes remove the mulch and loosen the soil 2" or 3" deep.
Prune back all dead parts at least to living wood and also shorten
the living parts from a third to two-thirds. The new shoots will
be much stronger and blossom more freely than if all the living parts
are allowed to remain.
The small flowered varieties may be pruned even more severely-a half
to three-quarters of the living wood. Many gardeners cut the Japanese
or sweet au- tumn clematis (Clematis paniculata) back within 12"
or 18" of the ground each spring.
Pruning the tops of both large and small flowered kinds concentrates
the plant food in the remaining living parts which are thus stimulated
to grow and blossom more' freely.
Copyright Information: Gardening
Short Cuts
See also Annual flowering vines
