How to cultivate the Clematis
Clematis (Clematis L. 1753) is a species that belongs to the Ranunculaceae family. These are bushy, climbing plants with copious inflorescences. In this sheet we will see the characteristics and how to cultivate the Clematis, following the most appropriate agronomic techniques.
These are plants that, due to their versatility, flower diversity, flowering periods and infinite range of colors, are suitable for cultivation in large and small gardens or in large vases on terraces.
The Clematis is a plant that prefers a sunny area but with shadowing of the root zone.
To have a luxuriant growth it is necessary to choose an area where the plants can have the roots in a fresh, damp and quite drained soil, without water stagnation.
Furthermore the clematis, in order to grow, need supports that must be chosen according to the green furniture chosen (wall, single plant, etc.); it is thus possible to use racks of iron or wood planted in the ground or fixed to a wall, or wire mesh with large meshes.
For the cultivation of Clematis in the open ground let us remember that these are generally plants that prefer soils with a pH varying from neutral to sub alkaline, even if they grow well even in slightly acid soils. If you are in the presence of clay soil, it is good to add mature manure and coarse sand to increase the aeration of the soil.
If you intend to cultivate in pot, good quality universal soil is sufficient.
For planting operations in the open ground it is advisable to proceed as follows:
– dig a hole at least 50 cm deep and 40 cm wide. In the case in which the Clematis must climb on the wall, it is advisable to dig the hole away from 40 to 50 cm, from the wall, meanwhile to avoid the immediate contact of the roots with the walls and also because, near the wall may be residues of construction, cements, etc.
– once the hole has been prepared, it is necessary to place 3-5 kg of mature or pelleted manure on the bottom, over a sprinkling of loose soil, pressing to prevent the soil from settling, place the clematis with the earth loaf and the central barrel inclined towards wall or support to which it will climb by calculating that at least 1 node remains buried, in older specimens also 2 nodes must be buried.
– Shade the foot of the plant with another perennial or seasonal plant, which has a minimum height of 40-50 cm with a compact habit, which has no roots that compete with the roots of the clematis.
Since clematis can also be cultivated in pots, we see the most useful devices.
Meanwhile, let’s remember that these plants develop the root system in depth; for this reason it is necessary to choose deep containers, depending on the specimens to be implanted, which are 35 to 50 cm high, and preferably terracotta, which allows transpiration. On the bottom of the pot always create a draining layer with very coarse or perlite gravel and avoid saucers with water stagnation.
Let us also remember that when plants are grouped, one benefits from the other, both for shading and wind, and the aesthetic aspect is more harmonious and natural.
Once the plant has been placed in the pot and the soil has been injected, it is advisable to place on the surface of this a layer of fine vegetable mulch that allows the substrate to be kept cooler, especially during the hot hours of summer days. As for pruning it should be remembered that clematis have numerous species and infinite hybrids that bloom at different times of the year, some bloom on old wood and others on new wood, therefore pruning varies according to the period of flowering and the species to which they belong.
For the cultivation of the different types of clematis, they are divided into three groups.
Group 1 – Clematis that need a light cleaning after flowering.
The clematis belonging to this pruning group are: C. Armandii and the evergreens, C. Alpina, C. Macropetala, C. Montana and C. Cirrosa.
In this case the pruning is light and should be done immediately after flowering, in the period from May to June. In addition, if needed, pruning can always be done after flowering. Furthermore, for the species C. Armandii, due to its exuberant vegetative capacity, a slimming pruning may be required but only for very large specimens. In this case the pruning should always be done after flowering, cutting a branch starting from the base at 1 m height; it is an operation that should be carried out every 2 – 3 years, or you can trim the stems, on a pair of axillary leaves.
Group 2 – Clematis that need an average pruning in February.
The clematis belonging to this group are large-flowered hybrids, with a flowering period from late spring onwards. In these species the flowers are produced on old wood, so the cuts must be made starting from the base, at 40 – 50 cm in height. Moreover in larger specimens it is advised, depending on the height of the stems, to reduce them by about half.
Group 3 – Clematis that require drastic pruning. To this group belong the large flower hybrids that bloom in summer. They are the C. Viticella, the hybrids of Jackmanii, C. Texensis and the C. Tangutica and all the herbaceous Clematis.
These clematis, since they bloom from summer to autumn on new wood, produced in the year, should be pruned vigorously in the period of February at about 25 cm from the base. For the herbaceous species, instead, we proceed to a drastic pruning, at ground level, because, during the winter, the aerial part dries up completely, so they must be cleaned eliminating the dry parts. Finally a hint on the phytosanitary problems.
It should be remembered cle clematis are very resistant plants with the exception of a virus (Clematis Wilt) carried by a fungus (Phoma clematidina) that can affect one or more stems even in full bloom. The symptoms are typical: the leaves and flowers collapse immediately (in 24 hours). Sometimes the plant has the strength to reject at the base; however, the affected stems must be cut as far as there are toned leaves. In general, however, the Clematis survives.