Rudbeckia: growing from seeds, species and varieties

Rudbeckia is a genus of herbaceous annuals, biennials and perennials in the Asteraceae family, which includes about forty species. In nature, Rudbeckia flowers are distributed mainly on the prairies of North America, in culture they are grown mostly in Europe and Africa. The first settlers in North America called rudbeckia “black-eyed Susannah” because of the dark middle of the inflorescence, but it seemed to Europeans that “sun hat” was a better name for the plant.

The scientific name was given to the rudbeckia by Carl Linnaeus in honor of the Swedish botanists, father and son Rudbeck, the younger of whom was a friend and teacher of Linnaeus, as well as great-great-grandfather of Alfred Nobel, and became famous for having discovered the human lymphatic system in 1653.

Botanical description

Rudbeckia flowers have simple or branched stiffly pubescent stems which grow to a height of half a meter to 200 cm, although some wild species can grow to three meters. Leaves of rudbeckia are entire, pinnately dissected or pinnately parted, oval or ovate, from five to twenty centimeters long, on long petioles in the lower part of the stem and sessile in the upper part. Inflorescences are baskets up to 15 cm in diameter, consisting of marginal barren lingual flowers in various shades of yellow and median ovipotent tubular flowers in various colors, from yellow to brown or purple-black.

The fruit of the rudbeckia is an oblong seed, sometimes with a small crown. Glossy, small, dark gray colored seeds germinate for 2 to 3 years.

Growing rudbeckia from seed

How to sow seeds

All species and varieties of rudbeckia, except the terry varieties, propagate generatively, and only perennial species can also be propagated by dividing the rhizome. If you don’t want to bother with seedlings, you can sow the seeds directly in the ground. This is done in mid- or late June: sow the seeds in prepared beds at a distance of about 15 cm one from the other and cover the top with a thin layer of soil, then abundantly sprinkle the seeds with water.

By autumn, small rosettes of leaves will appear on the bed, which next year will develop into lush bushes and bloom before the rudbeckia planted in spring. Rudbeckia in the garden also reproduces itself by self-seeding, and if with this phenomenon, but simply thin out the seedlings that appeared in the spring from under the ground, you can not resort to seed reproduction, relying on the wise nature.

Seedling care

Propagation of annual and perennial rudbeckia by seedling method begins in late March or early April, sowing seeds in seedling boxes, sprinkling them with a thin layer of soil and lightly spraying water from a sprayer. Under the film and at a holding temperature of 20-22 ºC, sprouts appear in one to two weeks. All this time it is necessary to moisten the soil in the boxes, remove condensation from the film and ventilate the crops as needed.

When two pairs of leaves appear, the seedlings are planted more spaciously so they don’t interfere with each other’s growth, and once they get the hang of it, begin hardening them by taking them out on a balcony or terrace for a few hours each day.

Planting Rudbeckia

When to plant in the ground

Plant the rudbeckia outdoors in late May, when the threat of night frosts has passed. Allocate a sunny area with fertile, water-permeable, cultivated soil for rudbeckia. In clay soil you need to add sand under the digging, but any soil before planting rudbeckia should preferably be enriched with compost. If part of the plot will be in the penumbra – no problem, rudbeckia grows well and in slightly shaded areas.

How to plant

In the open ground rudbeckia planted at a distance of 30-40 cm between copies. If in your region it is already summer, rudbeckia will quickly take root, but if the spring will be prolonged and the nights will be cool, planted in the bed rudbeckia should be covered overnight with agrospan until it will take root – after that, the plant is not afraid of low temperatures. In one place, perennial rudbeckia grows from 3 to 5 years, so it makes sense to mulch the area after planting with an eight-inch layer of compost.

Care of rudbeckia

Growing conditions

Planting and care for perennial rudbeckia contains no subtleties or secrets – everything as usual: watering regularly, morning or evening, in the hot season – frequent, after watering – loosening the soil on the plot with the simultaneous removal of weeds. Tall species and varieties of rudbeckia should be tied to supports.

At the beginning of the season fertilize Rudbeckia with a solution consisting of one tablespoon of nitrophoska, one tablespoon of potassium sulfate and one tablespoon of Agricola-7, dissolved in ten liters of water, based on the consumption of three liters of solution per 1 m² of land. In two weeks the same fertilizer is applied again. As the inflorescences wither, remove them with part of the flower stalk to the top healthy leaf.

Repotting

If rudbeckia grows in one place for more than five years, it gives abundant shoots, which clog up the site. In such a case, transplanting the rudbeckia to a new location is required. Dig up the bush, divide it and replant the parts in a new bed, observing the necessary distance between bushes. Both dividing and transplanting should be done when the rudbeckia has not yet begun its active growth period – in early spring or after flowering.

Propagation of rudbeckia

The propagation of rudbeckia by seed is described in the chapter “Growing rudbeckia from seed”, and the method of splitting the shrub is described in the previous section. There are no other propagation methods for rudbeckia.

Pests and Diseases

Of diseases, rudbeckia is very rarely, but still affected by powdery mildew. It looks like a loose white coating on the ground parts of the plant. To cope with the disease will help rudbekia spraying with a 1% solution of colloidal sulfur or a solution of copper sulfate at the rate of 80 g per 10 liters of water.

Sometimes there are cases of oppression of rudbeckia leaf nematodes, expressed by the appearance of brown spots on the leaves, their thinning and dying. Bazamid, Nemagon and Nemaphos are effective against nematodes in the manner specified in the instructions, sick and damaged specimens should be removed from the site. If an annual rudbeckia was affected, burn all its plant remains in autumn, and thoroughly dig over the plot and irrigate it with a strong solution of manganese solution.

Damage to rudbeckia and leaf-eating insects – larvae and caterpillars. However, in general, rudbeckia is a plant rarely exposed to diseases and pests, and if planting and care of rudbeckia is carried out in accordance with the requirements of agricultural technology, then you are unlikely to have problems with its health.

Rudbeckia after flowering

How and when to collect seeds

Rudbeckia blooms and gives seeds in the fall. Wait until the seeds are dry on the flower, then put on gloves and gently collect the seeds from the center of the flower, scatter them on newspaper and dry in a dry, ventilated room.

Perennial rudbeckia in winter

Perennial rudbeckia need to be covered for the winter, but first cut the plant residues to the surface of the ground, and then cover the area with a thick layer of humus (5-7 cm), lapnuts or dry grass.

Types and varieties

All cultivated species and varieties of rudbeckia are divided into annuals (they are also biennials) and perennials. The most common annual species in culture include:

Rudbeckia hairy (Rudbeckia hirta).

Native to North America, usually grown as an annual or biennial. Its stems are simple or branched, rigidly pubescent, about a meter tall. Radical leaves are petiolate, entire, ovate, while the stem leaves are alternate, broad-lanceolate, sessile, hairy, with coarse denticles. Inflorescences with baskets up to 10 cm in diameter grow on long peduncles. Reed flowers are yellow, tubular flowers are gray-purple, the receptacle is convex.

The most often cultivated varieties used are Toto Rustic, Goldflamme, up to 35 cm high; Marmalade, Babien Leto, up to 45 cm high; Goldstrum, up to 60 cm high, with simple inflorescences about 10 cm in diameter.

Rudbeckia bicolor (Rudbeckia bicolor)

A upright bushy plant, 25 to 70 cm tall with pubescent stems and lanceolate leaves. Bright inflorescences 6-8 cm in diameter have two rows of lingual yellow or orange flowers, sometimes with a purplish-black base. Tubular flowers on a cylindrical spike up to 2 cm tall have an almost black color. The flowering of bicolor rudbeckia begins in mid-June and ends before frost.

The most famous variety is Herbstwald – rudbeckia up to half a meter in height with inflorescences up to 7 cm across with red-brown lingual flowers and black tubular flowers.

Rudbeckia amplexicaulis

Grows to a height of up to 80 cm. Its leaves are opposite, sessile, glabrous, oval or elongate with a sharp apex and finely serrated along the edge. Its reed flowers are bright yellow, tubular, dark brown on a peduncle that grows to 3 cm tall.

Rudbeckia triloba

A lush but short-lived flowering plant 100-140 cm tall with three-lobed lower and oval dark green stem leaves. Inflorescences are small, lingual flowers yellow, tubular flowers dark brown.

Of the perennial rudbeckia species, the most commonly grown are:

Rudbeckia fulgida.

A perennial about 60 cm tall with solid, narrow, lanceolate leaves. Inflorescences up to 9 cm across consist of orange lingual and dark red tubular flowers. The glossy variebility has orange-yellow marginal flowers and dark purple median ones. In addition to this variety, the Goldsturm and Goldstar varieties with golden lingual flowers and a convex brown midrib are known in culture.

Rudbeckia laciniata

Grows to a height of two meters. Its rhizome is horizontal, strongly branched, the lower leaves are pinnatipartite, while the stem leaves are tricepartite. Inflorescences, up to 10 cm in diameter, consist of 1-3 rows of bright yellow marginal flowers and light yellow tubular flowers. Among the many varieties of this species the most common is Rudbeckia golden or semi-maximum with inflorescences up to 10 cm in diameter, consisting of bright yellow marginal flowers and greenish tubular flowers.

Rudbeckia occidentalis

A very unusual species that resembles the tongueless daisy. The Black Beauty variety of this species, for example, is devoid of lingual flowers, so it looks like a black cone surrounded by green bracts. The bush is 120-150 cm tall.

Rudbeckia maxima

A large plant, we can say, architectural. Leaves green with a blue waxy patina, lingual flowers bright yellow, growing on a strongly projecting flower spike in the form of a cone tubular flowers of dark shades. The plant is hardy and drought-resistant. Inflorescences on long peduncles stand well in cuts.

Rudbeckia nitida.

A two meter tall shrub with glossy oblong-lanceolate leaves. Inflorescences reach up to 12 cm in diameter. Reed flowers are yellow, tubular flowers are green. Varieties of this species Herbstonn and Goldshirm look spectacular in the garden.

Rudbeckia speciosa.

Only 50-60 cm tall. The leaves of this species are oblong or rounded, irregularly serrated along the edge. Inflorescences up to 10 cm in diameter consist of orange-yellow lingual flowers with three teeth at the tip of the bend and black-brown tubular flowers.

Rudbeckia hybrida

Combined name of the Rudbeckia hybrida variety with very large inflorescences up to 19 cm in diameter with yellow or yellow-brown reed flowers, which reach a length of 14 cm and brown tubular flowers with a violet tint.

Rudbeckia or Echinacea

Everyone is well aware of the medicinal virtues of Echinacea, but few know that Carl Linnaeus classified purple coneflower as a member of the rudbeckia genus in 1753. Indeed, rudbeckia and echinacea are native to the North American prairies of the southeastern United States, and both grow in open spaces in fertile, moist soils. In 1794, however, the German botanist Menchus identified Echinacea purpurea (until then, Rudbeckia purpurea) as a separate genus.

So what are the differences between these plants? Firstly, the color of the inflorescences: Echinacea has lingual flowers that are not yellow-orange-brown like the rudbeckia, but purple or crimson. In addition, the peduncle and bracts of rudbeckia are soft, while those of echinacea are prickly, rigid, spiky and pointed. These features of the plant are reflected in its name – “echitnos” from the Greek means “prickly”. The third and main difference between echinacea and rudbeckia is its medicinal virtues. Unfortunately, the healing properties of rudbeckia are an unconfirmed myth.