Kerria: planting and care in the open field, shelter for the winter, how to propagate

Kerria japonica is an ornamental medium-sized deciduous shrub belonging to the Rosaceae family. The homeland of the plant is the southwestern territories of China and the mountainous regions of Japan. Named after William Kerry, gardener at the Royal Botanic Gardens, Kew, who lived in the 2th century. The shrub has become widespread due to its unpretentiousness, as well as spectacular and long flowering – it forms a large number of bright lush flowers that resemble small roses, and blooms for about XNUMX months.

Description of the Japanese kerria shrub

Japanese kerria is an openwork shrub, the height of which reaches an average of 1-2,5 m, some varieties can grow up to 3 m. The leading quality of the plant is fast growth, which allows you to experiment with the form of pruning.

The crown of the Japanese kerria has the appearance of a cone. Shrub shoots erect, twig-like. Their surface is painted in light green tones.

The leaf plate in many ways resembles a raspberry leaf. The length can reach 8-10 cm, lanceolate in shape, serrated at the edges and tapering towards the end. The upper side of the leaf plate is smooth to the touch, there are small villi on the bottom. Petiole glabrous, 5-15 mm long. In summer, the foliage of kerria is light, pale green, and in autumn the shrub is transformed – the leaves acquire a rich yellow tint.

Flowers can be either double or simple – it depends on the particular variety. The average diameter of the flowers is 4-5 cm.

Winter hardiness of kerria

Winter hardiness in Japanese kerria is average. In the south of the country, where the climate is mild, shrubs can be left without shelter for the winter. In the conditions of middle latitudes and in the north of Our Country, the plant is insulated. It is very important to cover kerria where winters are not snowy.

The color features of the shrub give it a decorative look even in the winter months – green shoots, reeking of yellowness, contrast beautifully with white snow.

Kerria in landscape design

The shrub looks equally advantageous both in single plantings and in group compositions, fitting perfectly into the overall picture of a mixed flower garden. The bright flowers of Japanese kerria allow you to harmoniously combine it with dark monochromatic conifers: thuja, juniper, spruce. Japanese kerria looks no less impressive as part of borders and hedges.

Among the best neighbors for Japanese kerria are horticultural crops:

• rose flower;
• wanted
• spirea (varieties that bloom in the summer months);
• azalea;
• mahonia;
• gamemelis;
• rhododendron;
• hazel;
• bladderworm;
• turf;
• scapula;
• forsythia.

Separately, it is worth noting that Japanese kerria looks good next to ground cover plants: periwinkle, tenacious, phlox.

How kerria blooms

The shrub blooms in late May-early June, there are also late-flowering varieties. The positive qualities of the plant include lush flowering extended in time – it lasts for 3-4 weeks. Depending on the weather conditions in the region, the duration of the flowering time of the bush may decrease or vice versa, slightly increase.

Sometimes, in especially favorable years, bushes can bloom again. Although the second bloom will no longer be as abundant, it will still give the garden a decorative effect.

The fruits of Japanese kerria are a small, juicy, dark brown drupe, obovate or hemispherical in shape, wrinkled, 4,8 mm long. If you grow a shrub in the conditions of central Our Country, then the fruits of the plant do not form.

Features of growing Japanese kerria in the Moscow region

Caring for Japanese kerria in the Moscow region in spring and summer is not much different from growing shrubs in other regions, but in autumn the plant must be carefully prepared for wintering. Otherwise, the bush will freeze with the onset of frost, especially if the winter promises to be little snowy.

You can start warming in October or November, always on a dry, cloudless day.

In the Moscow region, flowers at the Japanese kerria appear in May, even before the foliage appears. Flowering lasts up to 25 days.

Varieties of kerria

The genus of this culture is represented by only 1 species – the Japanese kerria itself. The lack of species diversity is compensated by a large number of varieties. Some of them are popular in Our Country.

Pleniflora

Kerria Japanese Pleniflora (Plena, Pleniflora, Flore Plena) is a straight-growing shrub with a dense crown. This variety of Japanese kerria blooms with small double flowers, as seen in the photo below. They reach 3-4 cm in diameter and resemble pompons. Solitary or 2-3 in leaf axils.

Golden Guinea

Kerria Japanese Golden Guinea (Golden Guinea) – a plant with an elegant leaf shape and rather large flowers. In diameter, they reach 6-7 cm. They are simple in type, not terry.

Variegata (Pict)

Kerria Japanese Variegata or Picta (Variegata or Picta) – a variety with flowers that have 5 petals. This variety is distinguished by the decorativeness of the leaf plate – it has a gray-green color and a light strip along the edge. Also on the surface of the sheet cream spots of small sizes are noticeable.

In the diameter of the kerria, the Japanese Variegata reaches 1-1,5 m, the height does not exceed 1 m. Usually the bush grows up to 50-60 cm in height.

Variegata kerria grows very quickly.

Albumomarginata

Kerria Japanese Albomarginata (Albomarginata) – a variety with simple flowers and small leaves. Along the edge of the leaf plate of this variety has a white border. Among other varieties, Albomarginatu is distinguished by the asymmetry of the leaves.

The Aureovariega

Kerria Japanese Aureovariegata (Aureovariegata) – terry variety of medium height. With good care, the bush grows up to 2 m. If the conditions are favorable, the flowering of Aureovariegata kerria stretches for 3 months.

Simplex

Kerria japanese Simplex (Simplex) – a variety with simple flowers. The shrub has the shape of a ball, grows in breadth, and not up. Bright yellow flowers of medium size are located in the axils of the leaves. During flowering, the bush looks like a golden ball.

Planting and caring for kerria in the open field

When choosing a place to plant a Japanese kerria, the following tips should be followed:

1. The shrub loves light and blooms poorly in the shade. In extreme cases, you can plant a crop in partial shade.
2. Drafts do not affect the development of the plant in the best way. It is better to plant it next to a fence or some kind of structure.
3. The best type of soil for Japanese kerria of all varieties is loam. This horticultural crop does not like dry soils, but wetlands should also be avoided.

The plant is planted in early spring, before buds appear. Autumn planting is also possible – a month before the onset of cold weather.

So that the shoots of kerria do not break from the wind, you can plant other flowering shrubs nearby:

• Kuril tea;
• bladderworm;
• spirea.

Coniferous crops will also serve as good protection.

Preparation of planting material

Japanese kerria seedlings do not need special preliminary procedures. If desired, you can put them for a couple of hours in a container with water or a special solution that stimulates root growth. So Japanese kerria will take root better in the open field.

Site preparation

The main condition for the lush flowering of kerria is loose loamy or sandy loamy soil. If the soil is heavy, it is diluted with fine-grained sand. The scarce plot is dug up and organic fertilizers are applied.

How to plant Japanese kerria

Landing is carried out according to the following scheme:

1. At the selected site, a hole is dug with a depth of about 50-60 cm. The diameter of the hole should correspond to its depth.
2. A bucket of compost mixed with garden soil in equal proportions, 100 g of wood ash and 50 g of mineral fertilizer are poured into the bottom of the planting pit.
3. After that, a seedling of kerria is lowered into the pit. The root neck should be at ground level.
4. Then the hole is covered with earth and watered abundantly.
5. To better preserve moisture, the soil under the bush is mulched.

Watering and top dressing

Kerria japonica is a moisture-loving plant, but it tolerates excess water in the soil extremely poorly. If the water begins to stagnate after heavy rainfall or frequent watering, the roots of the “Easter rose” will begin to rot. To prevent this from happening, during prolonged rains, watering is reduced or completely stopped. If heat and drought sets in, water a little more often, especially during the flowering period.

The frequency of watering is regulated by the state of the topsoil. The next time the bush is watered when the soil under it is completely dry. If, after watering or rain, a dense crust forms on the ground, the trunk circle is loosened by a few centimeters.

Kerria is fed with organic fertilizers, 2-3 times per season, preferably in late April-early May and June. Plantings respond well to fertilizer with rotted compost and horse manure in the spring. In autumn, wood ash and complex fertilizers (for example, Autumn Kemira) are added to the soil. For 1 m2 about 200 g of ash.

When flowering ends, an infusion of mullein, diluted in a ratio of 1:10, can be added to the soil.

pruning kerria

Japanese kerria is cut for sanitary purposes or to maintain shape in order to preserve the decorativeness of the bush. In March or April, you should inspect the shrub and remove all damaged shoots: frozen or broken under the weight of snow. To stimulate the branching of the bush, you can additionally cut the remaining branches by 1/3.

When the flowering of kerria ends, you can start pruning faded branches to branches that did not bloom – it is on them that buds will form for re-blooming in the fall. Around the same time, pruning is done in order to rejuvenate the shrub – for this, all shoots over 4 years old are removed. If the kerria crown has become too dense, it is thinned out. Since this culture grows very quickly, you can not be afraid to cut too much – the bush will recover in the shortest possible time.

Shelter of Japanese kerria for the winter

You can start sheltering Japanese kerria for the winter as early as October. The latest date is the second or third decade of November.

Warm the plant in dry, cloudless weather.

1. Gently bend the shoots to the ground, while trying not to break them. Kerria is not laid on bare ground, dry leaves or grass should be placed under the stems, and foam can also be used.
2. The stacked shoots are firmly fixed so that they do not unbend – for this, a special frame of stakes is used. It will also serve as a protection against snow, which can crush the bush if the rainfall is heavy.
3. A layer of dry leaves, spruce branches or wood shavings is placed on top of the frame.
4. Additionally, the bush is covered with lutrasil. You can use alternative shelter options, but the material must be well ventilated so that the plant does not rot.

Shelter is removed in the spring, when constant heat is established and the threat of return frosts has passed.

How to propagate Japanese kerria

You can breed Japanese kerria in the following ways:

• cuttings;
• layering;
• divisions;
• overgrowth.

From this list, it is especially worth noting cuttings and breeding by layering – these are the most popular ways to propagate kerria.

Harvesting cuttings is as follows:

1. In July, green cuttings are cut, in August – lignified.
2. Each cutting must contain at least 2 buds.
3. The bottom cut must be made obliquely.
4. Immediately after cutting, the cuttings are removed to a cold greenhouse, in partial shade or shade.
5. Cuttings take root almost always successfully, but this process is slow. For the winter, planting material is left untouched.
6. In the spring, in May, the cuttings are planted in separate containers. Grow cuttings at home.
7. A year later, the cuttings are planted in open ground.

Reproduction by layering is considered one of the easiest methods of breeding kerria. It happens in the following sequence:

1. In the spring, before the start of sap flow, they carefully examine the bush and choose one of the most developed shoots on it.
2. The branch is bent to the ground and placed in a furrow about 6-9 cm deep, it is not necessary to dig it in.
3. So that the shoot does not unbend, it is fixed with brackets on the ground.
4. After 2 weeks, young stems will begin to sprout from the layering. When they reach a height of 10-15 cm, the furrow is sprinkled with earth so as to cover the young growth by 5 cm.
5. By autumn, new shoots form their root system. At this time, they can be cut and transplanted.

Diseases and pests

It is customary to treat horticultural crops for prevention with various fungicidal agents against fungus and pesticides that repel insects. In the case of kerria, this is not necessary. Bushes do not get sick and do not attract pests. Health problems in Japanese kerria are limited to the danger of freezing in winter and the risk of root rot if the water in the soil stagnates. Otherwise, the shrub has excellent immunity.

Conclusion

Kerria Japanese is a horticultural crop that easily adapts to various growing conditions. The only significant drawback of the shrub is its poor resistance to frost – even adult plants and the most winter-hardy varieties need shelter for the winter. As an exception, we can single out only those shrubs that are bred in the very south of Our Country, where the mild climate allows them to be grown without additional warming.

You can learn more about how to grow Japanese kerria in the garden from the video below:

Reviews about kerria