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How To Grow Clematis:
Clematis must surely be one of the best climbing plants we could
wish to grow. The diverse flower forms in numerous colours and
shades, make these gorgeous climbers are one of the most popular
plants grown in Britain today.
Clematis are not just summer flowers, they have
early flowering varieties, mid season and late flowering types, so
if you want to have flowers almost all year round, by selecting the
appropriate varieties you can have blooms for a good part of the
year. The clematis is a member of the buttercup family. This genus
includes approximately 250 species and numerous garden hybrids. It
is a varied genus, made up of mostly woody, deciduous climbing
plants, though a few are evergreen and a few herbaceous. Clematises
are hardy plants and can survive for 25 years or more. Leaves are
opposite on the stem and mostly compound with three to five
leaflets. The leaf stalk twines like a tendril and is responsible
for giving the plant support. The flowers are showy, having four
(sometimes five to eight) petal-like sepals (no true petals).
There are three general flower forms: small
flowers in panicles or loose and irregular spreading clusters; bell
or urn-shaped flowers; and flat or open flowers. The large-flowered
hybrids may have blooms ranging from 4 to 10 inch. (10cm-25cm) in
diameter and as many as 100 blooms per plant in a season. The
species types have blooms ranging from 1 ½ in.-3in. (38mm-76mm)
diameter with diverse shapes and habit; some of the species have
fragrant blooms, which is not true of most hybrids.
ANNUAL CLEMATIS MAINTENANCE: Once the plant is well
established, some basic care is needed on an annual basis. In dry
seasons, watering deeply once a week is recommended. Renew mulch to
a two-inch depth in late spring after the soil has warmed unless a
groundcover plant or other method is used to cool the root
environment. All most every fertilizer contains three main
ingredients: nitrogen (N), phosphorus or phosphate (P) and potash
(K). Nitrogen encourages leafy growth and is a key element, because
healthy foliage is essential for overall healthy plant. Phosphate is
especially valuable in encouraging root development and so is very
useful at planting time to aid initial establishment. Potash plays
an important part in promoting flowering and fruiting, especially
significant with a flowering ornamental like the clematis. Most
blended fertilizers also contain other minor nutrients like
magnesium, calcium and boron.
One very important element we haven't mention yet
is iron, which helps in the process by which the green colouring
matter, chlorophyll, is manufactured. Use a fertilizer containing
sequestered iron; good commercially prepared fertilizers will
contain this vital ingredient. When planting, use a fertilizer with
a high phosphate content; bone meal, applied, as a good handful to
the planting hole is ideal. Each spring give the plant a handful of
a proprietary rose fertilizer. During the summer when the plant is
growing rapidly, a general-purpose liquid feed such as the type used
for tomatoes can be given.
Plants will need about one inch of water per week during the growing
season applied through irrigation or rainfall. To maintain the soil
around the established clematis in a moist condition, mulch around
the roots making sure that the soil is wet thoroughly before the
mulch is added.
CLEMATIS PROPAGATION: Success propagating clematis by
cuttings or layering can have something of a mixed success rating
depending on experience. Cuttings taken in May or June from
half-hardened shoots of the current season's growth can increase all
types of clematis. Use a rooting mix of two parts sand and one part
peat and a rooting hormone (available at garden centres). Supply
high humidity, warmth and light in order for the cuttings to root
within four to five weeks. The large-flowered hybrids will take a
little longer to root; if cuttings are taken in May, they may not
root until late August. If rooted by early August, plant them out.
If no rooting occurs until late August, hold plants over winter in
pots and plant in early spring.
Layering is the easier method and can be done in
early autumn. Choose a mature stem produced earlier in the season,
or from the previous season's growth. Secure it into the soil at the
nodes or bury a pot containing a mixture of equal parts sand and
peat and secure the stem into this. Rooting occurs within about 12
months at which point the rooted sections can be detached and
re-planted.
CLEMATIS PROBLEMS: The most devastating condition of clematis
is a fungal stem rot and leaf spot caused by the fungus Ascochyta
clematidina and commonly called "wilt." This is a disease found
generally on large-flowered hybrids. Small-flowered hybrids and the
species and their cultivars are less susceptible to wilt. Symptoms
include a sudden stem collapse generally just as the flower buds are
about to open, and within a few days, the stem and leaves turn
black. Any part of the plant can be attacked down to and just below
the soil level. The usual treatment is to remove the diseased stem
below the wilted section, even below soil line.
Plants usually recover from buds lower on the stem. Powdery mildew
is another fungal disease that can occur on flowers and young stems,
usually in July and August. It should be treated with a fungicide
when first noticed as the fungus can disfigure leaves and flower
buds, causing them not to open.
CLEMATIS HISTORY: There was very little interest in clematis
until the 1850s when many were crossed and improved. Plants from
Japan and China became the parents of many hybrids. Breeders in
Britain, France, Belgium and Germany were responsible for many of
the varieties bred during the period of the 1890s; in fact, more new
varieties were introduced during this period than any other in
history and many clematis grown today originated then.
The leading hybridiser in Britain in the 1860s
was the Jackman Nursery, which produced C. x jackmanii (introduced
in 1862), still the most popular clematis grown today. In the 1880s,
interest in clematis waned; Hybridisers were running out of ideas
and the wilt "epidemic" put a damper on cultivation. Today, there is
renewed interest in clematis, particularly in very hardy and
disease-resistant small-flowered types.
CLEMATIS CULTIVATION: Clematis have a reputation for being
difficult to grow, however, like any other plant, if their needs can
be met by the site and proper care, they will thrive. Clematis
requires full sun to grow best though some dappled shade during the
heat of the day is beneficial. Flowers of some red and blue
large-flowered hybrids and the ones with delicately pale flowers,
fade badly if they get too much direct sun. Those are better planted
in eastern exposures or partial shade. The site should be open
enough to allow for air movement around the plants.
Soil should be rich and well draining with a pH
close to neutral (7.0). Though the plant's stems and foliage should
be in sun, the roots like a cool, moist environment. With the
exception of C. montana, clematis do not compete well with large
tree roots. Most clematis will require staking so the twining leaf
petioles can cling and climb upward, though some gardeners choose to
let the plants sprawl over the ground, low walls, other plants, etc.
TRANSPLANTING CLEMATIS: If you need to transplant your
clematis then it should be transplanted in autumn, late winter or
very early in spring before growth begins. Dig as large a root ball
as is possible (make sure soil is moist); the more roots preserved,
the less the transplanting process will stress the plant.
PRUNING CLEMATIS: The main purpose in pruning is to help
plants produce the maximum number of flowers and at the height,
which they can be enjoyed, so annual pruning is recommended.
Sometimes older, neglected plants can be cut back into older wood
and new buds may break. Growth from old wood will likely be weak and
slow. If the plants are not pruned at all, they would still grow and
flower but the blooms would be well above the ground, in many
situations they might even be well out of sight. Not all clematis
can be pruned in the same way. There are three methods that can be
applied to major groups depending on the time of year the plant
flowers. Some clematis flower on the previous years wood, those are
the earliest flowering varieties, but the later flowering types must
make new growth in order for flower buds to form. A few plants are
not strictly bound to the following groups but may cross lines.
Because vines will likely be entangled, make cuts carefully among
the intertwining vines and spread and train them in various
directions in order to cover the maximum possible area. This enables
the plant to display its blooms rather than be bunched up. Training
shoots horizontally not only keeps the flowers within eye level, but
also provides better coverage of the support, and the reduced flow
of sap encourages more flowers.
CLEMATIS VARIETIES:
GROUP A: Early-flowering Clematis Plants in this group bloom
in early spring, generally in April and May, from buds produced the
previous season. Prune these back as soon as possible after bloom
but no later than the end of July. This allows time for new growth
to produce flower buds for the next season. Remove shoots that have
bloomed. You can prune out more stems to reduce the size of your
plant if it has become untidy, or to form a good framework of
branches. Do not cut into woody trunks. Plants in this group
include: C. alpina, C. macropetala, C. armandii, C. montana and C.
chrysocoma.
alpina 'Frances Rivis'
GROUP B: Large flowered hybrids bloom in mid-June on short
stems from the previous season's growth and often again in late
summer on new growth (these blooms are smaller). Prune in February
or March by removing dead and weak stems, then cut back remaining
stems to the topmost pair of large, plump green buds. This cut could
be a few inches to a foot or two from the stem tips. You may be able
to force a flush of new growth from the base by cutting the stem
back to 18 in. (45cm) immediately after the flush of bloom in June.
Plants in this group include: 'Nelly Moser,' 'Miss Bateman,'
'General Sikorski', 'Duchess of Edinburgh,' 'Lawsoniana', 'Mrs.
Cholmondeley'.
GROUP C: Late-flowering Clematis. Plants in this group flower
on the last 2 -3 ft. (60cm-90cm) of the current season's growth.
Some types begin blooming in mid-June and continue into the autumn.
This is the easiest group to prune since no old wood needs to be
maintained. In February or March cut each stem to a height of about
two to three feet. This will include removal of some good stems and
buds. Eventually the length of the bare stem at the base will
increase as the vine matures. Plants in this group include: C.
campaniflora, C. viticella, C. flammula, C. tangutica, C. x
jackmanii, C. maximowicziana, 'Perle d'Azur,' 'Royal Velours,'
'Duchess of Albany' 'Alba Luxurians'.
CHOOSING CLEMATIS PLANTS: Plants are available in garden
centres and nurseries, though one good way of choosing your plants
is on-line through one of the specialist suppliers. The species and
small-flowered hybrids have fibrous roots that are susceptible to
root damage; disturb roots as little as possible. Select plants that
have multiple stems, healthy, dark green growth and a root system
that fills the container.
Article
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