Black cohosh: planting and care, photo, growing from seeds, use in landscape design, propagation

Planting and caring for black cohosh can be done by the most inexperienced gardeners, and the result can decorate the garden for several decades. The plant is considered the most elegant representative of perennial crops from the buttercup family. Elegant, tall candle flowers are popular in the design of gardens, parks, and flower beds around the world; they are used in bouquets and in folk medicine.

What kind of plant is “black cohosh”?

Black cohosh, or in Latin “cohosh,” received different names in different cultures. The green parts of the plant and roots contain insecticidal substances that can repel insects, which is reflected in the Latin and Russian names of the crop. Their German name, “silver candles,” most accurately describes the appearance and unusual beauty of flowers.

A large plant with tall, powerful peduncles can reach a height of 2 m. Depending on the variety and lighting, average black cohosh specimens grow from 40 to 100 cm.

With age, black cohosh develops a powerful root that goes deep into the soil. This provides the long-lived perennial with resistance to heat, frost, and drought.

Large, bright leaves rise from the ground, collected in a tall, growing rosette. Depending on the type, the leaf blades can be painted in all shades of green, have a reddish, blue tint, or be completely chocolate-burgundy. The shape of the leaves is thrice dissected, jagged, vaguely reminiscent of very large parsley.

One, rarely two, strong shoots rise from the rosette of basal leaves. At the end, a large peduncle of cylindrical or elongated pointed shape is formed. The black cohosh inflorescence contains hundreds of small buds with small petals, but very long stamens, giving the flowers a fluffy appearance.

The color of black cohosh flowers depends on the variety and varies widely from pale green to white and from bright pink to pale purple. The opening of the buds begins from the base of the “candle” and gradually rises to the tip. The flowering period can be extended to 40 days; in early species it begins in July, in later species in September or October.

The use of black cohosh in landscape design

The variety of black cohosh species in terms of height, length of inflorescences, and their color allows you to create many compositions in flower beds, alpine slides, and borders. Black cohosh in garden design can both create a bright accent and become a background for other plants.

When planting alone, you should choose tall, bright varieties: European or Daurian cohosh, atropurpurea. The same species are often used to decorate the banks of reservoirs and are grown along fences or walls. Medium-sized black cohosh looks good in prefabricated flower beds, and low-growing black cohosh decorates rock gardens, borders, and flower beds.

Black cohosh in landscape design, as seen in the photo, can be perfectly complemented by low-growing or cover crops. Hosta, maple leaf, anemone, perennial moss, hoof grass not only decoratively frame black cohosh plantings, but also serve as protection for the soil. Climbing lungwort and brunera perform a good mulching function.

Attention! It is important to select plant species for proximity to black cohosh that require similar growing conditions and thrive in moist, semi-shaded places.

Fern, aconite, sedge, buzulnik, and astilbe grow well next to black cohosh. Coniferous plants and bergenia serve as a noble background, highlighting the beauty of flowers and leaves.

How does black cohosh reproduce?

Having a perennial bush in the garden, it is easy to propagate black cohosh, obtaining several plants in the shortest possible time. To do this, you can use one of three methods: germination from seeds, cuttings, division of an adult bush.

Flowering, fragrant black cohosh is the most difficult to obtain from seeds. This will take about six months before germination and several more years of cultivation before the flowers appear. Vegetative methods are fast, but unreliable. Black cohosh planting material often dies due to temperature changes, bright sun or drying out of the soil; waterlogged seeds are dampened.

Cuttings

The propagation procedure by parts of the stem is best done in the spring.Black cohosh cuttings taken in the fall need to be rooted and cultivated at home before planting, which requires more attention. This method does not greatly disturb the mother bush; for propagation, it is enough to separate from it a leaf with a small fragment of the central stem (the so-called “heel”).

From an adult black cohosh bush you can get several independent shoots that form around the main root every season. To ensure rooting, the cutting is placed with its heel in a growth stimulator for several days, and then planted in loose, moist soil.

Comment! The advantage of this method of planting black cohosh is that flowers can appear on the seedling in the same season, and the mother bush suffers slightly from the procedure.

Dividing the bush

An adult healthy black cohosh bush grows in width every year and takes up more and more space in the flowerbed. A 5-6 year old plant can already be propagated by dividing the bush into parts. The plant is first removed from the soil, dug deep on all sides.

The bush is divided into several parts, depending on its age and size. Moreover, it is better not to damage the main rhizome, carefully cutting off only young shoots with shoots or living buds. Separated cohosh bushes are planted in other flower beds or grown in containers for better survival. The mother plant can be buried in the old place.

Growing black cohosh from seeds

Seed propagation is a more painstaking task; it is used only when necessary. The short shelf life and limited germination of the material complicate the task. Growing simple black cohosh from seeds has several features.

Step-by-step instructions and tips for seed propagation of black cohosh:

Planting material collected in the fall loses its viability with each month of storage. Therefore, it is better to start planting immediately after flowering.
Black cohosh is sown in containers with loose substrate and then left in a warm room (at least + 20 °C) for 90 days. Water the plantings rarely, keeping the soil semi-dry.
Covering containers with film for a “greenhouse” effect is not recommended. Black cohosh seeds are prone to damping off under such conditions.
The containers will need to be kept at a temperature of about + 16 ° C for another 90 days until seedlings appear.

Grow sprouts like ordinary seedlings. Planting plants in open ground is possible at any stage of development. It is important to monitor the air temperature to protect the seedlings from returning cold weather.

Young cohosh when grown from seeds will look like in the photo for several seasons. The bush develops and gets stronger, but flowers will appear on it only after 4-5 years.

Important! A significant disadvantage of black cohosh seed propagation is the fact that the seeds do not ripen in the middle zone. So in the Moscow region, flowers often disappear under the snow, and in the cool season there may not be any flowering.

Planting and caring for black cohosh

Much of the success of growing black cohosh comes from planting it. The perennial grows well up to 25 years in a permanent place, but is difficult to transplant. Therefore, the site should be assessed very carefully. Proper planting and careful care of the black cohosh plant may not yield results if the location is chosen incorrectly or the seedlings are inattentively selected.

When purchasing seedlings from a nursery or growing them yourself, you should carefully inspect each sprout before planting it in a flowerbed. There should be no stains on the leaves, shoots, or roots.When planting a black cohosh seedling, the buds should be alive or have already begun the growing season, and the shoots should not be lethargic.

Optimal time for planting

Black cohosh can be planted in spring or autumn. Experienced gardeners recommend doing this after the cold weather ends and the air warms up to + 15 °C. Spring planting provides black cohosh a whole season to take root. The bushes go into winter fully formed, so they are less susceptible to freezing or damping off.

Over the summer and autumn, the plant gains strength and adapts to the environment. By its condition, the black cohosh bush manages to show whether the site for cultivation has been chosen correctly.

Choosing a suitable location

The uniqueness of black cohosh is its ability to develop and bloom in partial shade. This property is highly valued by designers and amateur gardeners. Black cohosh makes it possible to decorate those places in the garden where other crops are reluctant to grow.

Advice! The optimal site for planting and growing black cohosh is considered partial shade or a place exposed to sunlight for only a few hours a day.

Soil preparation

Black cohosh, as a tall and abundantly flowering plant, needs increased nutrition. The soil for planting seedlings should be prepared carefully:

The selected area is dug deeply, adding sand, peat, and mineral fertilizers if necessary. There is no need to lime the soil - black cohosh loves acidic soils.
Since black cohosh grows in one place for more than 20 years, planting holes are made no less than 50*50 cm with a distance of at least 0.6 m between bushes.
Drainage must be laid at the bottom of the pit: expanded clay, small stones, broken bricks, gravel.
About 1/3 of the hole is filled with organic fertilizer mixed with garden soil.Rotted manure and compost are used as backfill; ash or complex fertilizers are added. On heavy soils, sand is mixed in.

If the planting holes are properly filled, black cohosh will develop well and will require additional feeding only after several years of cultivation.

How to plant black cohosh correctly

Plants are planted in prepared holes when the average daily temperature exceeds + 15 °C and the threat of night cold snaps has passed. It is advisable to transport the plants along with a clod of earth. If the root system of the seedling is open, the roots in the hole should be straightened so that they are directed inward.

You should not compact the soil tightly when planting black cohosh. When the planting hole is filled to the top, it is spilled with plenty of water. It is useful to mulch the surface around the bushes with dry peat, grass or sawdust after planting. This will save moisture and ensure looseness of the soil.

Attention! Mulch should not come close to the stems. About 5 cm of open ground is left around the black cohosh, otherwise the plant may dry out.

Growing and caring for black cohosh

After planting, caring for the black cohosh flower consists of moderate watering, fertilizing, and pruning. An important point is also preparing the plant for winter. You will not have to perform any more complex procedures when growing black cohosh.

Watering schedule

Black cohosh loves moisture and does not tolerate drying out of the soil, which is clearly signaled by the withering of leaves and peduncles. Overwatering a flowerbed can also cause the bush to become diseased. Growing in places with stagnant moisture leads to the death of plantings.

According to gardeners, it is better to water the plants rarely but abundantly, giving nutrition to the deep-lying roots.In hot weather, cohosh bushes, even those in the shade, are watered every 3 days.

Does the plant need fertilizing?

Black cohosh is sensitive to soil fertility, but proper placement of planting holes fully provides the plant with nutrition for the next 3 years.

Starting from the 4th season, black cohosh is fed for lush flowering and decorative foliage. Nitrogen fertilizers are applied in early spring. When planting buds, complex preparations for flowering crops or phosphorus-potassium mineral compositions are added to watering.

Advice! Black cohosh is responsive to organic feeding. You can mulch the bushes with rotted manure or peat before the winter season.

Loosening and mulching

Weeds rarely bother adult plants, because black cohosh has a lush rosette of leaves, creating a dense shadow under the bush. Therefore, weeding of flower beds with black cohosh will not be required often. It will simplify the care of ornamental bushes by mulching or growing low plants nearby in a flower bed.

A layer of organic bulk materials up to 5 cm will protect the flower bed from drying out and keep the soil loose for a long time. Sawdust, leaves, and peat are used as mulch.

Preparing black cohosh for winter

Adult black cohosh tolerates winters in central Russia well. Flower growers near Moscow claim that black cohosh winters well without any shelter. In areas with harsh winters or lack of stable snow cover, plantings can be covered with a layer of leaves or spruce branches.

Important! For a good wintering of the roots, it is important not to feed the plant with nitrogen from the second half of summer. This way, by the fall, the black cohosh root will have time to prepare for the dormant period and will not deplete its strength by excessive foliage growth.

Do I need to prune black cohosh for the winter?

Before the onset of cold weather, the stems and leaves of the plant are cut completely flush with the ground. This technique is usually sufficient to prepare black cohosh for wintering. After pruning, young bushes can be mulched with a layer of up to 10 cm. This technique is especially relevant in areas with harsh winters or frequent temperature changes.

Pruning black cohosh at other times consists of thinning the foliage, removing faded shoots and decorative shaping of the bush. This formation can be carried out at any time of the warm season.

Diseases and pests

Proper planting and sufficient care of the black cohosh flower results in a healthy, strong bush, not prone to disease, and not damaged by pests. The culture has a high immunity to fungal infections, including scab.

The plant most often gets sick due to waterlogging of the soil. In combination with cold soil, this condition can provoke powdery mildew infection. Similar conditions arise in the spring with unexpected cold snaps at night. For prevention, black cohosh leaves emerging from the ground are sprayed with Bordeaux mixture, Fundazol or Topaz.

Growing mistakes: why black cohosh doesn’t bloom

Black cohosh foliage is bright, juicy, collected in luxurious bushes, decorative in itself. But, without waiting for flowering, novice gardeners try to find and eliminate the cause. Often the plant does not throw out flower stalks or the buds that appear do not open, regardless of the quality of care.

Possible natural reasons why black cohosh does not bloom:

Lack of sunny days. Although the plant is a shade-loving plant, in particularly cloudy summers the flowers do not open and the flower stalks wither.
Cold spring or unexpected cold snap in summer.Black cohosh flowers cannot tolerate temperatures below + 15 °C. Stems may not develop or buds may fall off.
If the soil dries out for a long time or a dense crust forms on the ground, the plant begins to save nutrients and black cohosh may not bloom.
Growing in too much sun or full shade may produce beautiful foliage but leave the plant without flower stems.

Of the mistakes in care, the main obstacle to the development of cohosh is excess moisture, which provokes root rot. A lack of microelements also has a detrimental effect on the condition of the bushes. The fact that it is time to feed the plant can be judged by the condition of the leaves, which become pale, dry out or wither.

Many black cohosh inflorescences appear in mid-summer, but the flowers do not open immediately. Late-flowering species may simply not have time to fully develop in a temperate climate. If the summer in the region is short and it gets cold early in the fall, you should choose the earliest varieties of black cohosh for growing.

Conclusion

Planting and caring for black cohosh is not difficult. To successfully grow an ornamental plant with amazing flowers that look like silver candles, you need to maintain a balance of light and shadow, moisture and dryness of the soil. With minimal attention, black cohosh can decorate a garden for decades, becoming more beautiful every year.