Growing cosmos from seeds: practical advice for beginners

Author: Elena N. https://floristics.info/ru/index.php?option=com_contact&view=contact&id=19 Category: Garden plants Published: February 10, 2019Last edits: January 20, 2021

Cosmea is a flower that has been familiar to us since childhood. It’s just that when we saw cosmos bushes near the entrance, in parks, squares and vacant lots, we didn’t know the name of this plant. Thanks to its undemanding conditions and care, as well as its resistance to adverse environmental factors, the Mexican aster has become widespread throughout the world.

Read our article and you will find out:

• what types and varieties of cosmos are most popular in culture;
• how to grow cosmos seedlings;
• when to transplant seedlings into a flower garden;
• how to care for cosmos during the season:
• How perennial plant varieties overwinter.

Planting and caring for cosmos

• Planting: sowing seeds in the ground - in early spring, as soon as the snow melts, or before winter; sowing seeds for seedlings - in March or April, transplanting seedlings into the garden - from mid-May to early June.
• Flowering: from mid-June to September.
• Lighting: bright sunlight.
• Soil: any, but loose, well-drained, moderately fertile, slightly acidic soil is preferable.
• Watering: weekly and abundantly - 4-5 buckets for each bush.
• Feeding: three times per season with complete mineral fertilizer: before the formation of buds, during the budding period and before the start of flowering. Foliar feeding is also welcome.
• Reproduction: seed.
• Pests: For young plants that have not yet matured, slugs and snails pose a danger.
• Diseases: the plant is very resistant to any infections.

Read more about growing cosmos below.

flowers (lat. Cosmos) , or cosmos , or Mexican aster belong to the genus of perennial and annual herbs of the Asteraceae, or Asteraceae, family, numbering more than twenty species. The name comes from the Greek word kosmeo and translated means “decoration”. The tropics and subtropics of America are considered the homeland of cosmos; most species of cosmos grow in Mexico. In our climate, only three species of this genus are grown - two annual cosmos and one perennial.

Detailed information about the cosmos plant

People call cosmos simply, space. Moreover, both in Russia and in the plant’s homeland, in South America, where climatic conditions create an ideal environment for the flower, and in North America. But the botanical name of this annual or perennial plant has never sounded like that.

This flower from the Astrov family - it’s funny that the name also has a reference to stars and distant galaxies - has more than four dozen varieties, although only half of them are grown in garden conditions. However, these are only registered varieties! All cosmos are united by a similar external description.

You should familiarize yourself with it before planting cosmos to grow from seeds:

• Numerous shoots up to 1.5 meters in height, all rich green;
• The leafy structure of the greenery, the leaves are thin and numerous;
• Large paniculate-type inflorescences with a diameter of up to 12 centimeters;
• Tubular buds with large yellow pollen that attract pollinators.

Botanical description

The cosmos plant reaches a height of 50 to 150 cm. Its stems are thin, flexible, erect and branched. The leaves are opposite, twice dissected, openwork, graceful. Inflorescences-baskets, similar to daisies, up to 12 cm in diameter, grow singly or are collected in loose corymbose panicles. The middle flowers in the baskets are small, tubular, yellowish, and the reed flowers are large, purple, pink, red, white, golden yellow.

• Harmful and beneficial insects in our garden

You can often read or hear the expressions “terry cosmos flower” or “growing terry cosmos,” but this does not mean that we are talking about any particular species, it’s just that in recent years, breeders have developed double varieties of plant species that have long been cultivated. The fruit of cosmos is a dark yellow, gray or brown achene. Cosmos seeds remain viable for two to three years.

Independent collection of seeds and their selection for sowing

Cosmos seeds ripen well even in the middle zone. Despite the flowering that continues for quite a long time, they can be collected in large quantities on plants on which fading flowers have been left already at the beginning of autumn.

Cosmos are available for sale everywhere. When purchasing, it is enough to follow general precautions and selection rules.

Due to the fact that cosmos seeds remain viable for more than three years, one purchase or collection of seeds usually lasts for a very long time.

Growing cosmos from seeds

How to sow seeds

The cosmos flower is propagated by seeds, both by sowing directly in open ground and by seedlings. When to plant cosmos seeds in open ground? A cosmos flowerbed is sown in early spring, after the snow has melted. The seeds are scattered on the surface of the soil in nests, three to four pieces every 30-40 cm, and lightly smacked with the palm of your hand so that the planting depth is no more than one centimeter.

Flowering of cosmos when sown without seedlings begins in July-early August. You can sow cosmos in open ground in late autumn, before winter. In addition, cosmos reproduces well by self-sowing in the fall; all you have to do in the spring is to thin out the densely sprouted shoots.

Seedling care

Growing cosmos in seedlings gives more reliable and faster results. When to sow cosmos seedlings? In March or April. Photosensitive cosmos seeds sown on top of the substrate are lightly pressed into the soil without sprinkling, moistened and the seed is covered with film or glass. The container with the seed is kept in a bright place. If the temperature for seed germination is between 18-20 ºC, sprouts will appear in a week or two.

Dense seedlings need to be thinned out so that the distance between seedlings is 10-15 cm; for this purpose, picking can be done. Pickled seedlings are grown at a lower temperature - 16-18 ºC. If you don’t want to bother with picking seedlings, you can immediately sow two or three seeds in separate cups.

Reproduction

When growing cosmos in temperate climates, the seed propagation method is used, with direct sowing of seeds in the ground or using seedlings. Cosmos seeds have excellent germination and a long shelf life of 2 to 5 years. Number of seeds per gram: from 140 to 200 pieces. The time until the first shoots appear is about 2 weeks.

When sowing cosmos seeds in open ground, two planting options are used:

• solid;
• nesting

In the first case, the seed material is simply carefully distributed over the entire surface of the flower bed, lightly pressing with the palm of your hand and sprinkled with a thin layer of fertile soil or humus. It is not recommended to bury seeds when planting, as this may delay the emergence of seedlings.

In the second case, small holes are first made at a distance of 30-35 centimeters from each other, into which 3-4 plant seeds are placed, after which they are sprinkled with earth. To speed up the flowering time in areas with cool climates, cosmos is often grown through seedlings. In addition, the use of this method is very convenient when forming flower beds that combine plants of various shades, shapes and sizes. In this case, cosmos seeds are planted in prepared containers (containers or pots), 2-3 pieces in each of them, covered with a layer of plastic film or glass and placed in a place with good lighting and a temperature of +18...+20 degrees. The first shoots with this planting method will appear within 10-12 days. After they reach 10 cm in height, the young seedlings dive. To form a more voluminous, branched crown, seedlings of tall varieties can be pinched in the phase of appearance of 5-7 leaves. However, in this case, the cosmos will bloom a little later.

How the Catharanthus flower is grown can be seen in the contents of this article.

When it is necessary to sow Gatsania and in what way for the best result this article will help you figure it out.

You can see how flower beds made from Marigolds look in the article here: https://2gazon.ru/ozelenenie/cvety/vyrashhivanie-zdorovyx-barxatcev-iz-semyan.html

Planting cosmos

When to plant

Cosmos planting is carried out in early June, when the return frosts have passed and the seedlings will stretch up to 6 cm. Planting in mid-May is acceptable if you are sure that the cold will not return. Find an open sunny area for the cosmos, protected from the wind, with moderately fertile, well-drained, slightly acidic soil. Too fertile soil promotes the lush growth of greenery, but, alas, the quality and intensity of flowering suffers from this.

• Caring for gazania after flowering

How to plant

So, in mid-May or early June, when the weather finally gets warm, prepare shallow holes in the garden according to the 30x30 or 35x35 pattern if you are going to plant tall varieties, and water them. Then plant the seedlings in the holes, dig them in and water them again. Do not forget that tall varieties of cosmos may require support, so in advance, when planting seedlings, dig in slats or rods around which you will tie an adult bush. When the cosmos reaches a height of 50 cm, pinch the tops of the shoots so that the plant bushes better. Cosmos grown from seedlings blooms in June or mid-July.

Cosmos care

Growing conditions

Planting and caring for cosmos is not burdensome even for beginners in floriculture. Watering cosmos is carried out once a week, and it should be plentiful - four to five buckets of water should be poured under each bush. After watering, loosen the soil in the area and remove weeds until the cosmos becomes a mature, strong plant.

Feeding cosmos with fertilizers for flowering plants is carried out three times a season: before budding, during it and at the beginning of flowering. For more abundant flowering, you can perform foliar feeding - spraying the leaves with Bud, but when fertilizing cosmos, remember that moderation is needed in everything. Remove fading flowers promptly.

If the cosmos in the flowerbed has grown greatly, you can cut it, this will not stop flowering, and the bushes will become compact and more attractive. That, in fact, is all you need to know about growing cosmos flowers.

Pests and diseases

Cosmea is so immune to diseases and pests that it is practically not affected by them. Only slugs and snails pose a threat, and only until the plant has come into full bloom. You will have to deal with shellfish by collecting them manually. Place bowls of beer around the area and collect gastropods that come crawling to feast on it from time to time.

Planting in open ground

Cosmea does not require special preparation for sowing:

Prepare the soil before sowing: if the site has not been cultivated before, it must be thoroughly dug up. In a normal area, loosening will suffice.

Remove weed roots. Thorough weeding is not necessary - whatever catches your eye.

Make small holes about a centimeter deep in loose soil. The distance between the holes is about 30cm.

Place 3 or 4 seeds in each hole, carefully sprinkle with soil and water a little.

Cosmea after flowering

How and when to collect seeds

Perennial cosmos propagates by tubers and cuttings, and annual cosmos in the garden after initial planting will propagate by self-sowing for several years - from three to five. If you want to get cosmos seeds, leave the largest buds on the bush for the fruits to ripen, and to prevent the ripened seeds from spilling on the ground, put gauze bags on the flower heads. As soon as the seeds darken, it is time to remove them. However, you should know that cosmos plant is cross-pollinated, so the seeds do not retain varietal characteristics, and it makes sense to simply buy seed from well-established manufacturing companies.

Perennial cosmos in winter

When the perennial cosmos blooms, it is better to trim it, leaving only 15 cm of stems on the bush. For the winter, the cosmos is covered with spruce branches.

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Cosmea in landscape design

Cosmea in landscape design photo of flowers

There are many trends in modern landscape design. Cosmea is perfect for decorating a garden in the style of Country, Garden Hi-Tech, Art and Craft.

It is combined with low-growing and tall plants. Good neighbors will be daisies, delphinium, lily, mallow, aster, geranium, flax, calendula, bells, cloves, alyssum, salvia.

Types and varieties

Three types of cosmos are grown in culture - two annual and one perennial. True, these species, thanks to breeders, have many varieties and hybrids. So, we present to you annual species of cosmos:

Cosmos bipinnatus

An annual herbaceous plant from the mountainous regions of Mexico with erect, densely branched stems ranging from 80 to 150 cm in height. As the name implies, the foliage of this species is dissected into thread-like lobes, so it looks like dill leaves. Baskets from 7 to 10 cm in diameter grow singly or are collected in large corymbose inflorescences. The colors of the marginal flowers are white, red, pink, purple, and the tubular flowers form a small yellow disc in the middle of the basket. Cosmea bipinnate blooms profusely and gives good self-seeding. In cultivation since 1799 and today it is the most popular species in floriculture. Varieties:

• Dazzler – the blooming inflorescences have a bright red hue, but after a while they turn crimson;
• Purity - cosmos white as snow, with flexible stems;
• low-growing cosmos of the Sonata series, which includes the Sonata Pink Blush variety - pink cosmos with a red rim around the middle.

Cosmos sulphureus

Distributed in Latin America, this is a very heat-loving species with branched, erect, pubescent stems up to one and a half meters high. The leaves are twice and thrice dissected into wide pinnate lanceolate lobes, pointed towards the apexes. Reed flowers are orange or golden yellow, tubular flowers are yellow with protruding dark anthers with orange ends. In culture since 1799. Varieties:

• Bilbo – orange cosmos with semi-double inflorescences;
• Crest Lemon – lemon-yellow cosmos growing up to 50 cm;
• Diablo - this cultivar has fiery red inflorescences.

Blood red cosmos (Cosmos atrosanguineus)

Perennial cosmos is represented by such a species as blood-red cosmos, brought to us from the same Mexico. Sometimes this species is called black cosmos, because its red color is very dark, and its velvety flowers smell like chocolate. The leaves of this species are complex, consisting of an unpaired number of leaflets. Since red cosmos is an exceptionally heat-loving plant, it is recommended to grow it in pots that can be brought indoors for the winter. If you decide to grow blood-red cosmos in open ground, you will have to cover it for the winter.

Recently, terry cosmos has become increasingly popular. Most often, the following varieties attract the interest of gardeners:

• Brightness - abundantly flowering bushes with bright double inflorescences;
• Antiquity is a unique variety of compact cosmos with flowers that gradually change their original Burgundy wine color to salmon with a bronze tint;
• Double click rose bon-bon is a variety with very large double pink flowers that last a long time when cut.