Reproduction, Vaccination And Care Of Clematis

2024 Author: Sebastian Paterson | [email protected]. Last modified: 2023-12-16 13:47

Read the previous part ← General information about clematis, types and planting

Clematis pruning rules

And what about the stems on the supports? There are rules for pruning different groups and varieties, depending on which shoots they bloom on.

Pruning clematis is necessary for full-fledged abundant flowering, control of flowering times, natural renewal and the formation of a beautiful bush shape. In all cases, as for roses, all leaves are removed from the shoots in autumn, and if they have been affected by a fungal infection, they are burned. It is important not to infect the ground during the winter.

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The first pruning group includes clematis, in which flowers are formed on the shoots of the previous year, while a small number of flowers may be on the shoots of the current year. This group includes species and varieties of the section Atragena (princes), Montana (mountain), as well as grape-leaved, purple, Tangut, serrate clematis, etc.

They are grown almost without pruning, or after flowering, the generative part of the shoots is cut off. In autumn, their shoots are removed from the supports, cut off at a height of 1 m from the ground, and all dry, diseased and weak branches are also removed; the shoots are laid on a layer of spruce branches (isolation from the ground and protection from mice), then they are covered with an inverted box, etc., as described above.

The experience of collectors suggests leaving the pruning for the spring, so that in the event of a prolonged warm autumn, not to provoke the germination of renewal buds, which are actively growing immediately after pruning, and will inevitably die in winter, especially if frosts hit without a snow cover. The method of laying the stems for the winter is also varied. For example, the stems removed from the supports are thrown over the lower crossbar of the trellis, and a sheet of film is placed on top of them, partially fixing it to the ground, but leaving the ends free for ventilation.

The second pruning group includes species and varieties that bloom both on the shoots of the current year and on last year's shoots. These include the Lanuginoza groups, Florida, Patens. The first wave of their flowering occurs in late May - early June on the shoots of the previous year, it is short, but very decorative, the flowers are large. The second wave of summer flowering occurs on the shoots of the current year from July to autumn.

Pruning is carried out in two steps to ensure long-term flowering. In the summer, after spring flowering, the generative (faded) part of the shoots of the previous year is cut off, and if the bush is very thickened, then the entire shoot is removed to the base. In the fall, the faded part of the shoots of the current year is cut off, so that in the spring there is a full-fledged first wave of flowering, as well as to extend the maturation of seeds in breeding.

The third pruning group includes clematis, the bulk of the flowers of which are formed on the shoots of the current year. These are the groups of Jacqueman, Vititsella, Rect, blooming from July to September. Their maximum flowering occurs at the end of July - August. Pruning of this group is the simplest: after flowering, before shelter, all shoots are cut to the first true leaf or to the base.

This group also includes herbaceous and semi-shrub clematis, in which the shoots die off by the end of the growing season, and in the spring they grow back without pruning. But if you keep some of the stems without cutting, they will bloom 2-3 weeks earlier than on new shoots of the current year. Pruning clematis is also important for plant health, when diseased shoots are removed so as not to infect healthy ones, say, with powdery mildew.

Pruning has to be done involuntarily when cutting clematis during the growing season. After pruning, the plants are additionally fed, for example, with Kemira for the early growth of shoots (and this does not contradict the main application of AVA).

Pinching of individual shoots is done to delay flowering, and also combine pruning methods during breeding work, normalizing flowering and achieving full ripening of seeds.

Reproduction of clematis

Varietal clematis are propagated mainly by green or semi-lignified cuttings, as well as by grafting on the roots of specific clematis. Cuttings from young (2-3 years old), healthy, well-developed plants from the shoots of the current year root best of all. They are cut off in the budding phase - at this time they contain the maximum amount of their own biostimulants.

Cutting time - from March to September, for early cuttings use protected ground both for mother plants and for rooting cuttings. The rooting substrate consists of two parts. The lower layer is made of humus with a thickness of 20-30 cm, the upper one is made of washed river coarse sand or peat, or from a mixture of them 1: 1, or perlite with a thickness of 4-5 cm.

In summer, cuttings are taken directly from growing plants, using the middle, most ripe part of the shoot with well-ripened buds. The apical part of the shoot with flower buds is not suitable for rooting. The shoot for grafting is cut over the first true leaf. Cuttings with one knot are cut from it, above which 2-3 cm of the stem is left (or cut it out to the very buds, as is customary in Sweden); two buds in the leaf axils and a pair of leaves. If the leaves are large, to reduce the evaporation of moisture, their leaf blades are shortened by half.

But in this case, there is a great danger of early infection by spores of pathogenic fungi. The length of the stem under the buds can be from 1-2 to 10 cm, more often 4-5 cm. At our Control and Seed Experimental Station in the city of Pushkin, we usually left 2-3 cm of the stem at the top on the cutting (it is convenient to hold the plant for this part when planting), under the kidney - only 1-1.5 cm. The lower cut can be treated with root root or other root formation stimulant. The prepared stalk is immediately planted directly, after 4-5 cm in a row and 10 cm between rows, in a box or a growing bed with a moistened substrate, deepening and tightly squeezing the knot. After planting, watered abundantly through a fine sieve.

Clematis keeping mode

Rooting of green cuttings requires high relative air humidity (85-100%), which is achieved by multiple spraying and keeping cuttings under cover made of glass or film, plastic. For the first three weeks, the shelter is not removed, raising only for spraying. Then the frames are gradually opened, leaving on the stand, up to 1-2 hours a day. Rooted cuttings are ventilated all day, closing the frames at night.

The substrate should also be constantly moderately moist. The air temperature is maintained within + 22 … + 25 ° С. Higher temperatures are harmful to plants. As well as for cuttings of other plant species, these cuttings also need a light shade in the form of slatted frames, tension of lutrasil, burlap, whitening glass of a greenhouse or greenhouse with chalk, etc., before they take root. Initially, a callus forms on the lower cut for 3-4 weeks, then roots develop from it, as well as from the subrenal meristem, internode cambium. The root formation process lasts 6-8.5 weeks. The rooting rate of different species and varieties varies, but on average is 60-90%.

During the rooting period, the growth of the aerial part of the cuttings is undesirable, since these shoots do not have time to mature enough, therefore they winter poorly, in spring they often die or grow poorly. To prevent this phenomenon, the growing shoots are pincer. But usually the development proceeds in such a way that in the first year the cuttings form a root, and the stems grow in the second year of life. As a rule, rooted cuttings remain overwintered in a greenhouse under frames covered with dry leaves, pressed mats, spruce branches, and branches. At the ends of the frames, gaps are left, covered with a sheet, for ventilation in winter in a thaw.

In the spring of the next year, usually about 60% of cuttings reach standard sizes: up to 10 or more roots, about 30 cm long. They are planted in a permanent place or in containers for sale. Underdeveloped plants are grown in open ground ridges or containers.

Baltic experts consider the most rational reproduction of clematis by lignified cuttings of autumn pruning, since the stems are still cut off, but flowering is not disturbed in summer. Its difficulty lies in the fact that plants in the fall are preparing for dormancy, and all metabolic processes in them are inhibited. To achieve successful rooting, cuttings are stored for some time at a low temperature in storage.

Cuttings are cut into 1 or 2 knots, the sections must be treated with root formation stimulants at a concentration twice as strong as for green cuttings (0.05% heteroauxin or BCI with an exposure time of 15-24 hours, root powder), and planted obliquely in boxes in a greenhouse or room. The substrate is a moistened mixture of peat and sand in a ratio of 1: 1 or 2: 1. The cuttings are planted so that the lower end is at a depth of 3 cm, and the upper one above the kidneys is 1 cm.

The boxes are placed in a cool place (basement, cold greenhouse, pantry) and the substrate is kept at a moderate humidity. In the absence of such premises, the cuttings are left to winter in a greenhouse, covered with frames and additionally insulated. Around March, etiolated shoots begin to grow, and the boxes are brought into the greenhouse or room, where the temperature is raised to + 20 ° C in two weeks. Moisten the substrate as it dries. Young shoots that have grown up to 10 cm are pinched, and this technique stimulates root formation. Roots form in about 90 days in 80% of cuttings. Young shoots newly regrown up to 10 cm are cut into cuttings and rooted, as is customary for green cuttings.

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Vaccination of clematis

By grafting, clematis are often propagated in nurseries throughout the year by splitting or copulating in a greenhouse. The rootstock is the roots of varietal clematis or seedlings of species (Clematis viticella, less often Clematis vitalba, Clematis orientalis, etc.)

For winter grafting, the stock is stored in a trench in a basement or greenhouses, on open ground ridges under the shelter of peat, sheet, film, so that it is convenient to get them at the right time. 10-14 days before vaccination, the rootstocks are brought into the room and the temperature there is gradually increased. The roots should "wake up", as evidenced by the appearance of white cones of root growth.

Roots 4-6 mm thick with side roots are suitable for grafting. Scion - growing shoots that are cut into cuttings 4-6 cm long with one node at the top. The leaf blades are shortened by half. Next, choose one of the usual methods of vaccination.

Inoculation into the split is done when the thickness of the rootstock and the scion are equal, splitting the top of the rootstock vertically in the center by 2-4 cm in length. The lower end of the scion with a length of 3-4 cm is cut with a double-sided wedge, inserted into the split of the rootstock, combining the cambial layers, and tightly tied (bandaged) with a narrow strip of plastic film, securing the strapping with a double knot. When the stock is thinner than the scion, it is grafted onto a wedge - exactly the opposite, the top of the stock is cut in a wedge-shaped manner.

By copulation, thin and equal parts are grafted, making an oblique cut 2-3 cm long, sometimes with a small split (saddle), tightly connecting the scion to the stock, bandaging the connection with a film or woolen thread, leaving small gaps for lateral roots germination. The survival rate of vaccinations in compliance with all the rules reaches 90%.

The grafted plants are planted in boxes or pots in the same moistened substrate up to the node, covered with foil or glass so that the relative humidity does not drop below 85%. The air temperature on the shelves is maintained within + 18 … + 22 ° С. The grafting tissue grows together within 3-4 weeks. After that, the shelter is gradually opened, the plants are aired and accustomed to fresh air. The best time for vaccination is considered March - April. Of course, mother plants must grow in a greenhouse.

The division of bushes is used with a large shoot-forming ability of the variety, while 5-25 divisions can be obtained from a bush at the age of 5-10 years. Division is useful for thickened plants, as they bloom worse. It is better to do this in early spring, before the growth of the shoots. It is not always necessary to dig up the entire bush, you can do with digging a groove 50-60 cm deep from one edge. It is important to place a shovel radially to the center of the bush in order to injure the roots as little as possible.

The center of the bush is carefully freed from the ground, a number of rooted parts are separated with a pruner, and they are planted in a new place. Root slices are powdered with charcoal powder. The roots cut off during the digging process are used as rootstocks for grafting. The trench is then covered with nutritious soil, adding a compound fertilizer, preferably long-acting (AVA).

Dividing a spud clematis bush

In the spring, the bush, huddled in the fall, is undone for better growth of young shoots. When young shoots grow to a height of 50-60 cm, the bush is again covered with moist light and nutritious soil with a layer of 15-20 cm. This layer must be regularly moistened throughout the summer. Adventitious roots are formed by the end of summer, but it is better to separate the young parts of the plant next spring.

Vertical layering is obtained by hilling bushes with humus or peat to close 2-3 lower stem nodes. During the seasons, this layer of soil is kept moist, and after one to three years, the stems are fully rooted. The bush is broken in the spring, the rooted shoots are cut and planted in new places. This method does not disturb the roots of the mother plant and does not disturb the flowering.

Layers are the most affordable of all breeding methods for clematis. For diversion, both young and lignified shoots of past years are used. In the spring, lower lignified shoots are chosen, as they grow back, young strong shoots (you can continue abduction in summer and autumn), some of them are laid in grooves 8-10 cm deep, dug out radially from the bush, and pinned with wooden or metal pins so that they do not rise, while the top of the shoot is left on the surface of the earth. The bark is pre-incised under the knot, which stimulates root formation.

The stems are covered with nutritious soil and kept moist throughout the season. Another option is the retraction of 1-2 nodes of the stem, the rest of the shoots is directed up and tied to a support. In this way, you can significantly expand the not very powerful clematis bush. On the other hand, with good tillering, rooted layers are usually planted after a year, so as not to shade the mother plant and not to provoke the appearance of powdery mildew due to poor ventilation of the bush. There may be other abduction options.

Seed reproduction of clematis

You can start reproduction of species clematis by seeds, collecting them in the fall. Sometimes, for the full maturation of seeds, you have to cut off shoots with ovaries and keep them indoors in vessels with water. It must be understood that large-flowered varieties can give full-fledged seeds, but their offspring will not retain the parental characteristics of the variety.

On the other hand, only seeds from open ground make it possible to obtain frost-resistant new varieties (this is what MF Sharonova believed and achieved this). Experts believe that the latitude of St. Petersburg is the most northern for the ripening of clematis seeds, and this happens in October - November. The period of post-harvest ripening of fruits lasts from two weeks to 20 months, in proportion to the size of the fruits (the weight of 1000 seeds in different species and varieties ranges from 0.2 to 30.3 g).

The first group of large-fruited clematis has a fruit size of 6x5 to 12x10 mm, and such seeds sprout for a long time (after 1.5-8, or even 12-16 months) and unevenly. Germination lasts four years. These include Clematis lanuginosa, Clematis patens, Clematis parviflora, Clematis viticella and other species and varieties with large flowers. The second group of clematis has fruits ranging in size from 5x3 to 6x5 mm, they sprout together in 1.5-6 months. Germination remains up to 3 years (Clematis campaniflora, Clematis flammula, Clematis fusca, etc.). The third group includes the most common species in our area with fruit sizes ranging from 3x1.5 to 5x3 mm. Their germination is high, lasts 1-2 years, germination occurs within 15 days to 3-4 months. These include: Clematis tangutica, Clematis orientalis, Clematis heracleifolia, Clematis vitalba,Clematis serratifolia, Clematis virginiana and others.

Ways to accelerate the germination of dormant seeds are classical: soaking with water change 3-4 times a day; rinsing in running water, preferably with air blowing at the same time, for 4-5 days. Seeds of clematis of the first two groups are sown immediately after harvest in the fall and the crops are kept in a warm place.

There is a practice of sowing in half-liter jars on moist humus, filling the seeds with humus with a layer of 0.5 cm; the jars were covered with foil, tied and kept in a semi-dark place at room temperature (method of MF Sharonova). Seed germination begins in 2.5-3 months, the banks are exposed to light. Seedlings dive into boxes of 5x5 cm. Grown seedlings in July are planted in ridges according to the scheme of 50x50 cm.

The optimal mode of seed reproduction was found in a combined method, in which at first the crops are kept at + 20 ° С, then they need stratification at + 5 ° С for two months (in the refrigerator), and then + 18 … + 20 ° С, while the seeds sprout together. You can do the opposite, as it was at our Control and Seed Experimental Station in the city of Pushkin: sow seeds in late November - early December and keep the crops in a dark basement at + 2 … + 4 ° C, watering the substrate 1-2 times a week …

Seedlings appear in late February - early March. Now they are brought into a greenhouse with a temperature of + 13 … + 15 ° C, where germination is activated, and two weeks later they begin to pick according to the 3x3 cm scheme into a mixture of compost soil and peat (2: 1). At the end of April, the seedlings are taken out in hotbeds or greenhouses for hardening, later they are planted either in a cold greenhouse or in open ground (20x10 cm). Clematis tangutica with yellow graceful flowers on a well-leafed bush with such agricultural technology by September in greenhouses grew up to 1 m, and in open ground - up to 30-40 cm, and even bloomed.

This option is also possible: seeds of species clematis stratified within 1-1.5 months at + 5 ° C are sown in May in open ground. Seedlings dive in August or next spring. Another, the most convenient way: fresh clematis seeds are sown in a garden bed before winter, and then they germinate by themselves, sometimes within 1-2 years. Seedlings bloom, as a rule, in the 2-3rd year.