Home » Misc » Growing cosmos from seed

Growing cosmos from seed


How to Grow and Care for Cosmos

Cosmos are freely flowering annuals that are easy to grow by sprinkling some seeds in the garden after any danger of frost has passed. These quintessential cottage garden flowers reach full maturity in about two months. Cosmos can be slower to germinate, but it blooms quickly after that and continues to flower through the fall. The flowers sit atop long slender stems and form a cloud of attractive color all summer that attracts bees, butterflies, and birds to your garden. Cosmos flowers look a lot like daisies. They come in a broad range of colors, with more cultivars developed every year. The leaves grow opposite on stems and are deeply lobed, pinnate, or bipinnate and feathery-looking depending on the type. If you plan to have cosmos and live in the southern U.S., consider keeping them as potted plants since they tend to be invasive there.

Common Name Cosmos, Mexican aster, cut-leaf cosmos
Botanical Name Cosmos sulphureus, Cosmos bipinnatus 
Family Asteraceae
Plant Type Annual
Mature Size 1-6 ft. tall, 1-3 ft. wide
Sun Exposure Full
Soil Type Well-draining soil
Soil pH 6.0–6.8 (Acidic)
Bloom Time Summer through fall
Flower Color Golden yellow, white, pink, magenta, orange, yellow, red, chocolate
Hardiness Zones 2–11 (USDA)
Native Area northern South America, Central America, and southern North America

Cosmos Care

Cosmos grow easily in beds and make great cut flowers. When established, the plants can handle drought, poor soil conditions, and general neglect. They even self-sow. This is a truly low-maintenance plant.

While some pests, like aphids, flea beetles, and thrips feed on cosmos, they're easy to control with a strong spray of water or insecticidal soap. Aster yellows, bacterial wilt, and powdery mildew may also affect cosmos. Space plants accordingly to ensure good airflow to avoid diseases.

Taller varieties look good in the middle or rear of the border with goat's beard, coneflowers, and black-eyed Susans. Shorter varieties make very colorful, airy edging plants.

Warning

Cosmos sulphureus is invasive in the southeast United States. Check with representatives from your local extension office to learn about any restrictions in your area.

​The Spruce / Letícia Almeida  Tim Bird / Getty Images  The Spruce / Letícia Almeida

Light

For the best flowering, choose a site that gets full sun. Cosmos will grow in partial shade but will have fewer blooms and be less vigorous when planted in shady areas. These plants will also thrive under uninterrupted full sun in the hottest conditions, much like their native habitat: the arid regions of Mexico and Central America.

Soil

Cosmos plants prefer a neutral soil with a pH of 6.0 to 8.0, although they will grow in poor soil where many flowering plants languish. They perform best in medium moisture, well-drained soils, but they will perform adequately in dry soils. Avoid planting in a rich soil; it can cause the plants to get too tall and flop over. You can prevent drooping by staking the plants or growing them close to other plants that can support them.

Water

Once established, you will not need to water your cosmos plants unless there is a prolonged drought. Where water is limited, these are the last plants that require irrigation.

Temperature and Humidity

Hot weather is ideal for cosmos, and they thrive in any humidity level.

Fertilizer

Fertilizing can negatively impact cosmos. Cosmos can handle poor soil. Too much fertilizer can often lead to strong plants with lots of foliage but few blooms. Unless your plants seem to be struggling, these plants do not need fertilizer.

Types of Cosmos

There are over 25 species of cosmos. However, three species are most commonly used in gardens and landscaping. Cosmos sulphureus is native to Mexico, Central America, and northern South America. With golden yellow blooms, it is very drought tolerant and loves hot weather. The plant grows 2 to 6 feet tall and comes in double and semi-double flowers. Some of the more recent cultivars tend to be shorter, more orangy, and with smaller flowers.

Cosmos bipinnatus are colorful daisy-like flowers that come in white, pinks, reds, and orange. At 1 to 4 feet in height, they are shorter than C. suphureus and are available in several popular hybrid series. Although they are not quite as heat tolerant as C. sulphureus, C. bipinnatus will grow well in just about any sunny space.

Chocolate cosmos are a separate species: Cosmos atrosanguineus. The dark red flowers smell like chocolate. This perennial is hardy to USDA zone 7, but it is higher maintenance than annual cosmos. Like dahlias, it grows from tubers.

Other common cosmos cultivars include:

The Spruce / Letícia Almeida Eva Lechner / Getty Images Suzanna Ruby / Getty Images

Pruning

The only real maintenance cosmos plants need is deadheading which will prolong the flowering season. If you fall behind, shear the plants by about one-third, when most flowers have faded. This kind of pruning produces a second flush of leaves and flowers. By the end of the season, you can cut off the plants at ground level or pull them up, roots and all. However, if you leave the plants in place, they may self-seed for the following growing season.

Propagating Cosmos

Cosmos plants readily self-seed. It's best to propagate these plants after the threat of frost is gone. Although sowing seeds is the best and easiest way to propagate this plant, you can also propagate via stem cutting. When you take stem trimmings, it stimulates more leaf and flower growth. Besides seed, stem cutting is the best way to propagate this plant. Here's how you do it:

  1. You'll need sterile pruning shears or scissors and a pot of sterile, well-draining potting soil.
  2. Fill a small 3-inch container with moistened potting soil. Using a pencil tip, push straight down in the soil about 1 to 2 inches deep, making a shallow hole.
  3. Look for a cosmos shoot that has 3 to 5 leaf nodes on the stem. Cut under the last leaf node. At the last leaf node, carefully cut off the leaves, leaving the node intact for new growth.
  4. Bury the cut tip of the stem in the pencil-made hole. Make sure that the last leaf node is above the soil line. Push down the soil around the stem, compacting the soil to keep the stem upright and in place.
  5. Water generously and keep moist. You should notice new leaf growth within three weeks. If you do, you can gently pull the root ball out of the container, Transplant the root ball to its new location.

How to Grow Cosmos From Seeds

Start seeds indoors, four to six weeks before the last frost. Or if you can sow cosmos outdoors directly in the garden well after the threat of frost is gone. Cosmos grow very quickly but can be killed by a late frost, so don't rush it. They typically germinate in 7 to 21 days at 75 degrees Fahrenheit, followed by flowering in about 50 to 60 days.

Loosen the soil to a depth of 8 inches. Plant the seeds and cover them with 1/4 inch of fine soil. Seed packets usually recommend precise spacing, such as at 2-foot intervals, or you can scatter the seeds and let the plants support each other as they grow. You can always thin them out later, moving the extra plants to another part of the garden.

Potting and Repotting Cosmos

When growing cosmos in pots, make sure the container has bottom drainage holes. Cosmos can't handle overly wet, soggy soil. Plan on growing one cosmos plant per gallon of your container. If growing in pots, do not enrich the soil, it makes the plants grow tall, leggy, and droopy. Also, tall varieties will need staking in containers. At the very least, plan on using at least a heavy, 12-inch diameter container.

Overwintering

Cosmos is an annual. If left outside in frosty temperatures, they will die. However, at the end of the growing season, if you allow the dead flower heads to drop their seeds, cosmos seeds will go dormant and sprout when the soil warms up again in the spring.

If you have a potted cosmos in a container and want to keep your cosmos alive over the winter season, you will need a bright full sun growing lamp for at least 7 hours a day. You will need to snip off any blooms as they form. This plant's life cycle ends with flowering when it drops its seeds for the next growing season.

How to Get Cosmos to Bloom

Cosmos plants need full sun to bloom. Even the hint of shade, can restrict flowering. Also, to encourage more blooms, you need to deadhead the old blooms. For faster blooms, prune between the main stem and a leaf. The lower you cut in the stem, the longer it takes to grow more flowers.

Common Problems With Cosmos

Cosmos are easy to grow and maintain over the growing season. They are usually resistant to disease, and most insects; however, some pests can become a nuisance and affect their growth.

Wilting or Leaf Discoloration

If your plant has ample water and is not wilting from a lack of hydration, there are two possible causes.

A plant that is wilting with leaf discoloration might have a common fusarium fungal infection. If you dig up the plant and notice a pink mass on the roots, then the plant likely has fusarium. The whole plant is beyond help, will die, and should be disposed of to stop the fungus spread.

If you dig up the roots and they look healthy, the plant may have a bacterial wilt infection. The bacteria cause the stems to wilt at their base. This plant will die and should be disposed of.

Yellowing Leaves and Leaf Drop

Powdery mildew mainly affects plants in the shade. Fungus spores fly through the air and attach to a host plant in a shady spot. It creates a powdery white coating on leaves and causes leaves to yellow and fall off. To prevent powdery mildew, provide your plants good circulation, bright light, and avoid getting water on the leaves. If your plant has fungus, use a horticultural fungicide according to the package instructions.

Flowers Distorting or Stunting in Growth

As a member of the aster family, cosmos can get aster yellows, a disease spread by leafhoppers (a tiny grasshopper-looking insect). The leaves will get yellow mottling on the leaves, and the flowers will appear distorted or stunted. Dispose of these plants since there is nothing you can do help them recover.

FAQ

Article Sources

The Spruce uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.

  1. Cosmos sulphureus Cav.sulphur cosmos. United States Department of Agriculture.

  2. Cosmos (Cosmos). Connecticut State Agricultural Experiment Station.

  3. Cosmos bipinnatus. Missouri Botanical Garden.

  4. Fusarium Wilts. Royal Horticulture Society.

  5. Diseases of Cosmos. National Gardening Association.

  6. Powdery Mildew. University of California Integrated Pest Management.

  7. Cosmos: Aster Yellows. University of Minnesota Extension.

expert tips on when and where to plant |

(Image credit: Unsplash Mathew Schwartz)

Garden favorites for summer color, learn how to grow cosmos and you can enjoy clouds of these daisy-like flowers dancing in the breeze and filling garden beds and borders.

Ranging from pale pastels and whites through to bright pinks, crimson, orange and other zingy colors, these annuals are enduring favorites for flower bed ideas. They will happily self seed for several years, filling your yards with their open-faced blooms that can go on for months and months, adding to your palette of late summer flowers and still displaying their cheery blooms until the first frosts of fall.

Cosmos comes from the Greek ‘kosmos’, meaning beautiful, and growing tall with their fine, feathery deciduous foliage, cosmos are definitely one to include if you're planning a cut flower garden as the more flowers you pick, the more you'll get.

There are many cultivars available, including doubles, others with tubular rays and some bi-colors, in different tall and compact varieties.

Once you know how to grow cosmos you'll be using them to brighten up all corners of your garden.

How to grow cosmos from seed

(Image credit: Getty Images)

It is easy to get to grips with how to grow cosmos from seed and they can be sown any time throughout spring depending on the hardiness zone where you live. The seeds are large, long and thin, so easy to handle and germinate quickly.

'Cosmos are the very best, low-maintenance and floweriest plants in the world. With little effort, they give you buckets of cut flowers and they have a good vase life, too. Easy to grow, long-flowering and brilliant for picking, it’s hard to fault them,' says expert plantswoman, Sarah Raven .

These pollen-rich flowers are also an excellent lure for bees and other pollinators to attract them into a wildlife garden. 'They are stacked with nectar and pollen, so bees and butterflies love them,' agrees Sarah. too. 

Cosmos bipinnatus, the most commonly grown, also known as Mexican aster, originates from the Americas.

When it comes to growing cosmos from seed you have two options. You can grow them in modules or seed trays indoors, or plant them directly out in the garden. There are benefits to both. 

(Image credit: Future/Leigh Clapp)

How do you successfully grow cosmos?

Growing cosmos in modules or seed trays indoors to start them off, gives you more control over the blooms. Keeping them off the ground and under cover will also protect the delicate seedlings from slugs and harsh weather. Plus, since you are starting your plants off indoors, you are able to start planting earlier – in early spring – so will have well established flowers that attract bees by early summer. 

Sow indoors in module or seed trays, covered with about 2mm of good, fresh compost. Water from below, allow excess water to drain away and position in a warm place, ideally 60 to 70 0°F (16 to 21°C), to germinate, which takes around 30 days.

Move seedlings to a cold frame or light, sheltered spot for a few weeks before planting out to harden them off. This will result in 'much faster growing and longer-lasting flowers,' says gardening guru Monty Don on his blog . He also recommends doing the same for young cosmos that are bought in the garden center, too. 

Direct sowing cosmos outdoors

(Image credit: Leigh Clapp)

If you choose to direct sow cosmos outdoors, this is a low-maintenance choice that is beautiful for a cottage garden idea. 'I place them in groups so they make drifts and clumps rather than straight lines,' says Monty.

For how to grow cosmos seeds outdoors, wait until the soil has warmed up, then:

(Image credit: Getty Images)

Where do cosmos grow best?

Cosmos grow best in a sunny spot, protected from wind, with well-drained, light soil. It is advisable to mulch the ground to conserve moisture, and if you learn how to make leaf mulch you can use your own organic garden material.

If you live in a very warm zone that can suffer extreme heat, cosmos will tolerate part shade.

Cosmos tolerate most pH levels, but do best in neutral to alkaline soils and are quite drought tolerant, so might be worth adding to your planting palette if you're planning a dry garden. Long periods or wet and cold are detrimental and can delay flowering.

Plant your cosmos in a group to make a real focal point statement for late summer into fall until the first frost. This will also attract more bees than if they are dotted through the garden. 

Cosmos are useful for cheery color in any area of a backyard and suit a range of styles – from planting a cottage garden border, creating a prairie style naturalistic planting design, or planting a wildflower meadow.

‘I love to grow lots of different varieties of cosmos, putting together different heights and colors in pots and for borders for wonderful layers of intense colour,’ says Sarah Raven.

They are also excellent for companion planting alongside vegetable and fruit crops in a kitchen garden, as they entice pest predators and valuable pollinators. 'We plant cosmos with our vegetables, in rows to help support each other,' explain Henrietta Courtauld and Bridget Elworthy, the Land Gardeners .

When to plant cosmos seeds

(Image credit: Leigh Clapp)

Early spring is the best time to sow cosmos seeds under cover indoors, which will then produce flowers that bloom earlier in summer.

Alternatively you can direct sow cosmos seeds in their flowering position once the soil has warmed up. This will differ depending on the area where you live, but will be from about late May in cooler regions, and earlier in warmer zones.

Bought seedlings can be planted in late May or June.

Is cosmos easy to grow?

Yes cosmos are easy to grow. 'Cosmos is one of the easiest flowers to grow from seed that is directly sown in the garden bed,' advise the experts at American Meadows .

‘As they grow, stake cosmos if necessary, and water them regularly,' says Sarah Raven.

Cosmos suffer from few pest problems. Watch out for slugs and snails, though, especially when the plants are young and tender, so use slug barriers. To avoid powdery mildew and fungal diseases ensure your plants have space and the soil isn’t soggy. 'Cosmos prefer dry, arid soil over wet conditions. Soil that is too moist may lead to disease,' advise the American Meadows experts.

(Image credit: sarahraven. com / Jonathan Buckley)

Can you put cosmos in pots?

Cosmos, particularly the shorter varieties, can be grown in pots, and make attractive patio and container plants. As they are good at attracting beneficial insects to veg and fruit crops, why not include them in your vegetable garden container ideas? 

Try a mix of shorter dwarf cosmos varieties, such as the Sensation and Sonata mixes, grown from seed, or buy as seedlings and plant out from May, spaced about 11in (30cm) apart. Cosmos work particularly well in pots with zinnias.

Use a light potting mix, in pots with good drainage and place in a sunny spot. Water regularly and feed with a liquid fertilizer every few weeks during summer. 

(Image credit: Leigh Clapp)

How to keep cosmos flowering

If your cosmos aren't flowering, you could be making one crucial mistake. An important step in how to grow cosmos and keep them flowering is to deadhead the blooms. This stops the plant putting its energy into creating seeds and instead puts its efforts into creating more flowers.  

Chances are you will be busy in the garden deadheading roses and petunias, and other blooms, so add cosmos to the list.

'As long as you don’t cut the plants right to the ground, but above a pair of leaves, more buds will form to fill next week’s vases and more for the week after that. The lower you go in the plant, the more delay between the flower you've just picked and the next flower,' explains Sarah Raven. 

'We love cosmos because it is light and airy and has the joy of endless giving – every time you deadhead another flower appears,' add the Land Gardeners.

(Image credit: Thompson & Morgan)

Do cosmos come back every year?

Nearly all cosmos are annuals meaning they do not come back every year. In order to have blooms every year, you will need to resow the seeds the following spring. 

The only exception to this rule is chocolate cosmos, cosmos atrosanguineus, which is grown like a dahlia from a tuber and is a perennial. Chocolate cosmos is loved for its delicious vanillary-chocolate scent and velvety brown flowers, and since it is a perennial, will come back year after year. 

Annual cosmos can also self seed. If you let some of your cosmos flowers die naturally and fall to the ground they will germinate seeds by themselves. Allowing plants to self seed is a step on the way to creating an eco-friendly garden.

You may also like to try collecting seeds to save from the flowers to sow next spring. If you want to save seeds be aware that hybrids will not grow true-to-type, so select varieties that have been open pollinated, as opposed to hybrids – which can vary widely in the next generation.

You can collect cosmos seeds at the same time as you are collecting zinnia seeds and those of other flowers that you love. This is a cost-effective way to populate your garden with flowers, year on year.

Scatter the collected seeds in your garden or save in labelled envelopes or paper bags for sowing the next year.  

(Image credit: Leigh Clapp)

Do you pinch cosmos?

You should pinch out the growing tips of cosmos to encourage branching and flowering, and in around 12 weeks you should see your first blooms.

If you then want to enjoy those flowers in the house as well as in the garden, cosmos make excellent cut flowers. To harvest for cut flowers, cut the cosmos blooms when they are beginning to unfurl in the morning, as this is when there will be the most moisture making them less likely to wilt.

Plunge the blooms into a bucket of warm water, stripping off lower leaves to avoid them in the water. There are many tricks for how to keep flowers fresh in a vase. Re-cut the stems regularly and refresh the water and cosmos should last up to 10 days in the vase. 

(Image credit: Pippa Blenkinsop)

Do cosmos need staking?

The taller varieties of cosmos will need staking to prevent them flopping over.

They can grow up to 8 feet (2.5m) and flowers can reach 3 inches (8cm) across.

‘It’s worth taking the time to stake them properly as they benefit greatly from growing straight early on. If they collapse, they’ll never grow or flower as well as when vertically supported,’ explains Sarah Raven.

How often should I water cosmos?

Water cosmos regularly until they are established, or during dry spells. It is important, however, that you do not over-water cosmos as this can result in plants with fewer flowers. 

Cosmos can tolerate dry soil, even in a hot, sunbaked spot. In fact, they prefer poor soil and seem to thrive on a bit of neglect!

(Image credit: Leigh Clapp)

Do cosmos like sun or shade?

Cosmos are sun loving flowers, although they will tolerate a little shade in warmer climates.

Cosmos and zinnias are good companions and mix them also with other sun-loving plants in borders, beds, meadow planting and containers, such as Verbena bonariensis, alstroemeria, calendula, eryngium, dahlias and nepeta.  

'Cosmos can be combined with almost all full sun border plants to give that "wow" factor mid to late season. Infilled in a shrub border or alongside flowering plants, such as monarda, salvias and gaura works well,' says garden designer Charlie Bloom. 

The range of colors allows for diverse combinations, whether bright and breezy or more subtle, so there’s lots of scope.

Rachel is senior content editor, and writes and commissions gardening content for homesandgardens.com, Homes & Gardens magazine, and its sister titles Period Living Magazine and Country Homes & Interiors. She has written for lifestyle magazines for many years, with a particular focus on gardening, historic houses and arts and crafts, but started out her journalism career in BBC radio, where she enjoyed reporting on and writing programme scripts for all manner of stories. Rachel then moved into regional lifestyle magazines, where the topics she wrote about, and people she interviewed, were as varied and eclectic as they were on radio. Always harboring a passion for homes and gardens, she jumped at the opportunity to work on The English Home and The English Garden magazines for a number of years, before joining the Period Living team, then the wider Homes & Gardens team, specializing in gardens.

Growing cosmea from seeds. When to plant? At home — Botanichka

Charming Moscow chamomile, kosmos, or kosmeya is one of the flyers, without which no garden can be imagined. Weightless and openwork, delicate, with a calico pattern of pretty flowers against the background of a solid pillow of narrow leaves, kosmeya fascinates with its cheerful character and simplicity. Growing cosmea from seeds is easy even for beginner gardeners. After all, it does not even have to be sown for seedlings.

Cosmos bipinnatus. © Chloris

Contents:

The most popular double-pinnate cosmea and its hybrids are upright, large, densely bushy annuals from 80 cm to almost one and a half meters high. The leaves are needle-shaped, somewhat reminiscent of dill or fennel, creating a translucent elegant green mass. Against the background of bright greenery, weightless flowers flutter on tall and thin pedicels - basket inflorescences with a beautiful circle of wide reed flowers around a neat yellow center. The petals are very delicate and translucent. The color scheme of cosmea includes all possible shades of white-pink-red palette, sometimes in two-tone variations.

Despite the fact that today kosmei are represented by numerous varieties that allow you to choose a diverse palette of colors and even plant heights, the ease of propagation of these crops does not change. Without exception, all cosmeas are grown from seeds (both sulfur-yellow, and blood-red, and double-pinnate). Plants give abundant self-seeding, usually if they appear on the site, then forever. But it is not difficult to grow cosmea for the first time. For cosmos, you can use the method of sowing seedlings, although it is much easier to sow the seeds of space directly into the soil, to the place of cultivation.

When sown in the soil, Moscow chamomile usually begins flowering in July, growing seedlings allows for earlier flowering.

Self-collection of seeds and their selection for sowing

Cosmos seeds ripen perfectly even in the middle lane. Despite the continuing flowering for quite a long time, they can be collected in large quantities on plants on which fading flowers were left already in early autumn.

Cosmea is sold everywhere. When buying, it is enough to follow the general precautions and selection rules.

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

Conditions necessary for growing cosmea

When planting seedlings or sowing in the garden for Moscow chamomile, it is very important to choose the right place. Cosmos are one of the most sun-loving flyers and it will be impossible to admire the weightless beauties in shading.

The soil for cosmea should be fresh, light and loose, nutritious or at least medium nutritious. A high organic content is welcome, as is a sandy structure. Dense or too heavy soils can be easily improved with the addition of compost and sand.

Shoots of cosmea sown in the ground. © opustopiarium

Sowing kosmeya into the soil

Unlike some other annuals, sowing into the soil for kosmeya is carried out immediately in a permanent place, in greenhouses or seedling beds. But you can choose the timing of sowing at your discretion. Cosmea can be sown in the spring, and use the winter sowing method.

The sowing dates for plants are the same as the standard sowing dates for medium-cold-tolerant summers. Cosmees are sown in early May or April, when the risk of persistent night frosts disappears, but without waiting for the complete disappearance of recurrent frosts. Before winter, sowing is carried out when frost begins to bind the soil.

Cosmea is most often sown not in rows or furrows, but in shallow holes at a distance of 30-40 cm to create an ideal planting density and minimal thinning efforts. 2-4 seeds are laid out in the pits, thinning out the seedlings at the cotyledon stage and leaving only the strongest plants at the optimal distance. When filling large areas with Moscow chamomile, sowing can be carried out in the usual way.

When spring sowing, the soil is strongly moistened beforehand; when sowing in winter, no watering is carried out.

Cosmea seeds need light to germinate, so they are simply pressed into the soil, fixed in it, but not covered with earth. During winter sowing, places with cosmea seeds are covered with snow. In the soil or greenhouse in the spring shoots appear within 2 weeks.

Growing Cosmos through seedlings

The seedling method is generally only used for rare, new or improved flowering hybrid varieties. This method is inferior in popularity to sowing directly into the ground.

The soil and containers for sowing cosmea are selected from among the standard ones. Cosmea feels good in a simple purchased substrate for seedlings or self-composed loose and light earth mixtures of medium nutritional value. Sowing bowls should be shallow, but the choice of their size depends on personal preference. Cosmos can be sown in small individual cells or pots of 2-3 seeds, you can use large boxes and rare sowing with thinning instead of diving, or you can carry out standard sowing and pick seedlings. It all depends on the desired number of seedlings and the number of seeds.

Sowing seeds of cosmea for seedlings begins in March and continues until the end of April, adjusting the desired flowering time of the plant.

The technique of sowing kosmeya is very simple:

  1. Fill the containers with the substrate and gently moisten the soil with a spray bottle. The substrate is not compacted.
  2. Seeds are less often scattered on the soil surface or laid out at a distance of 9-10 cm (or in each cell), 2-3 seeds, lightly pressed down or left on the surface. For germination, cosmea needs access to light. From above, the seeds are moistened from a spray bottle.
  3. Containers are covered with glass or film.

Conditions for germination of cosmea seeds are not quite standard. In the heat, cosmea sprout worse, indicators from 15 to 18 degrees are considered the optimal temperature range. Containers with cosmea crops are exposed to maximum bright lighting.

Growing plants is carried out in the same conditions in which the sown seeds were kept - in cool and bright light.

Seedlings are dived only if they want to keep all the shoots, avoid thinning, and when not growing in separate containers. Seedlings dive after the appearance of a pair of true leaves. If cosmea was sown in large containers, the plants can be thinned out by removing the weakest ones and leaving the seedlings at a distance of 7-10 cm from each other. In individual containers, the weakest shoots are also simply pulled out.

Care for young kosmeya is standard, it comes down to careful watering, which does not allow drought or waterlogging. If the seedlings are stretched, the tops of the plants are pinched, but it is better to organize additional lighting and prevent the process of deformation of the sprouts, because tweezing negatively affects flowering and delays its onset.

Hardening of seedlings of cosmeas begins as early as possible, taking the seedlings out into the fresh air for at least a few hours a day on fine days.

Landing in a permanent place is carried out only after the threat of night frost has disappeared, in May. The distance when planting seedlings of cosmea is standard - from 10 to 30 cm to obtain a dense array and beautiful textural spots. The plant is not afraid of transplanting.

Seedlings of cosmos. © Racquel

Caring for Young Cosmos

Cosmos are surprisingly drought-resistant, but at a young age, at the very beginning of growth, it is necessary for the plant to maintain stable soil moisture. At a time when kosmeya increases the vegetative mass and up to the beginning of flowering in drought, it is better to water the plants. During the flowering period, watering is carried out only during severe droughts and in the heat, in order to maintain abundant flowering and stretch the duration of the flowering period as a whole.

When growing cosmos, top dressing is not at all an obligatory care item. They begin to carry out at the stage of budding, complete mineral fertilizers, repeating several times over the summer. During the vegetative stage, fertilizing can cause green growth at the expense of flowering. Excess nitrogen is especially dangerous for space.

If tall kosmeya was sown or planted in a windy area, as the bushes grow, it is better to take care of the installation of supports and a garter. Thanks to the light greenery, an ordinary peg is enough for the plant.

As soon as the first flowers appear, you should start to regularly remove fading flowers. Without such a simple procedure, the flowering of Moscow chamomile will be quite short and not so lush. To collect seeds, the largest flowers are left selectively, while the rest are regularly removed.

Due to its hardiness and resilience, pest or disease problems are rare in this plant. Usually, difficulties with rot arise only in an unfavorable autumn; young seedlings or seedlings of the disease are not afraid.

Cosmos: growing from seeds, planting, care, varieties, photo


COSME / COSMOS - ANNUAL PLANT FOR GARDEN AND COTTAGE

Cosmos - no garden or cottage usually does without this plant. Its decorative inflorescences and delicate leaves, as well as unpretentiousness and ease of cultivation, attract the attention of flower lovers and gardeners. Along with the traditional cosmea, which has come down to us from the front gardens of grandmothers, the plant is now represented by the most diverse, sometimes surprising varieties and forms. Therefore, it is interesting to know where this beautiful flower came from, how to properly grow cosmea, which variety to choose.

Cosmea is known to many under a different name - Cosmos, translated from Greek meaning "decoration". This genus of herbaceous plants belongs to the Asteraceae family and unites 46 species. Among them are annuals and perennials that grow naturally in Mexico and other tropical and subtropical regions of America. Some of them are used in ornamental gardening.

DOUBLE-PININATED COSMEA

Our most famous double-pinnate cosmea (Cosmos bipinnatus). It is unpretentious, easily tolerates the Russian climate (zones 2-11, for more information about frost resistance zones, delete here ) and reproduces well by self-sowing. In European culture, this species has been known since the end of the 18th century. And in her homeland, the American continent, she is more familiar under the name "Mexican aster." There, self-dispersing wild plants often play the role of a weed.

Bush, up to one and a half meters high, formed by strongly branched powerful shoots, which are covered with green openwork leaves. They are divided into narrow thread-like parts and are located on the shoots opposite each other.

Fairly large inflorescences-baskets, reaching a diameter of 7 to 12 cm in culture, and up to 6 cm in the wild, collected singly on a bare peduncle or collected in corymbs. They consist of marginal reed and central tubular flowers.

Reed flowers (petals) have three teeth at the top. Petals can be located both in one and in several rows. In cultivars, they can be pink, lilac, white, and two-tone.

Tubular small flowers, colored in yellow, collected in the center in the form of a small circle. Unusual varieties of double-pinnate cosmea with anemone-like inflorescences and with petals that have grown together in the form of a long tube have been obtained.

Abundant flowering lasts up to three months, usually from mid-June to September. Quite large brownish seeds of an elongated wedge shape retain high germination for three to five years.

SULFUR YELLOW

The sulphur-yellow kosmos (Cosmos sulphureus) is quite rare in our gardens, although it is also recommended for zones 2-11. It is believed that it suffers more in cool and damp summers, and may not even bloom. But in Korea and Japan, this type of cosmea is the most popular. 9. In the climate of the middle lane, this heat-loving crop grows poorly; tubers can rot from an excess of moisture in the soil. It works better in pots, which are transferred to a cool room for the winter. Like dahlias, chocolate cosmea tubers can be dug up and stored until spring.



GROWING COSMEA

Even an inexperienced summer resident can grow traditional cosmea (double-feathered), so it is better to start acquaintance with cosmea with classic plants. It will be somewhat more difficult with new selections and rare species, the cultivation of which will be of interest to experienced amateur flower growers.

This crop is a photophilous and cold-resistant annual plant that does not impose special requirements on growing conditions, tolerates hot and dry times well.

► Iberis ► PHIZALIS

Planting and soil

when choosing a place of place to avoid a partial shade and even more so the shadow, where the flowering will be significantly reduced. For tall varieties, the danger is winds that can break the tall thin stems of the cosmos. Such plants are selected protected space.

The best soil for space will be sandy loam with a neutral or slightly acidic reaction. It is very important that the soil is breathable, and water does not stagnate in it. Therefore, on clay soils, planting cosmos on high flower beds can be justified. Sand and compost, or other organic matter, are added to such soils to improve the structure. If you have a lot of humus in the soil in your area, add sand and clay to it before sowing the cosmea, since the cosmea does not bloom well on very fatty fertile soils, growing only green mass.

Cultivating space in a garden or country house is not difficult. For early flowering in the Non-Black Earth Region, cosmea is grown through seedlings, in the same way it is better to grow rare varieties and complex hybrids. But most often the seeds are immediately sown in a flower garden or in a garden bed.

GROWING FROM SEEDS

Seedlings for seedlings are sown in April-March (or one and a half to two months before the last frost) in low containers or pallets with small cells, filled with loose, slightly nutritious, breathable and acidic reaction. You can sow cosmea in separate pots with a diameter of about 10 cm, 2-3 seeds each, so that later the seedlings do not dive, but remove weak seedlings, leaving stronger ones. But this is acceptable in the case of a large number of seeds. They do the same with lowercase or free planting of seeds, thinning out the entrances after the appearance of two true leaves, and leaving 10-15 cm between the seedlings. If there are few seeds, each seed is immediately planted separately.

Seeding depth is approx. five millimeters. Sometimes it is advised to simply press the seeds into moistened and slightly compacted soil, without sprinkling with the substrate, explaining this by the high need of the plant and seeds for light. Crops are covered with a film, aired daily, moistened with a fine spray of water when dried. At an average temperature of +18 degrees, seedlings appear in two weeks or earlier.

Seedling containers are placed on a bright, cool windowsill. To prevent the seedlings from stretching, the temperature is maintained no higher than +18 degrees. Monitor the humidity of the substrate - it should not be very dry and very wet. In the phase of 2-3 leaves, the seedlings dive into separate pots or are seated at a distance of 10-15 cm in spacious plastic containers or boxes.

For better branching in tall cosmea varieties, pinch the top over the 6th leaf. Modern hybrids themselves form the correct bush and do not need such an operation.

Grown up plants are planted in open ground, depending on the region, in early-mid May or early June. Young bushes (not overgrown) tolerate transplantation well, take root quickly and begin to grow intensively.

GROWING FROM SEEDS IN THE GROUND

Sowing in the garden on a bed with loose and permeable soil is carried out 2-4 weeks before the end of frost to a depth of 1 to 2 cm.

Tall varieties are placed in beds or beds so that the distance between plants in a row planting is about half a meter, and between rows - sixty centimeters. And between undersized hybrids, the distance should be thirty centimeters, between rows - forty. When nesting planting, 3-4 seeds are placed at a distance recommended for the variety. The seedlings that have appeared are looked after as with the seedling method of reproduction.

Sometimes they practice winter sowing of space in frozen grooves or holes.

► TAGESTS ► GEDECIA

Cosmea Cosmea

Cosmea Cosmia consisted in loosening and weeds. It practically does not need watering, except at the beginning of growth and in severe drought. To do this, it is enough to water the plants once or twice a week. With the help of watering, you can increase the flowering time of cosmea, which stops earlier due to lack of moisture.

Cosmos grows well and develops even on not very nutritious lands. When growing this crop, it is worth remembering that it is not worth feeding bushes on black soil, since even small doses of fertilizers cause a delay in flowering and seed formation. In addition, on fatty soils, the cosmea grows very tall, which is why its stems may not support their own weight and break.

Fertilizing with mineral fertilizers (nitrogen and, to a greater extent, potassium and phosphorus) is required only on poor soils, as well as when growing cosmea in pots. But before that, the plants must be watered. The following terms of fertilizing are observed: at the beginning of the growing season, during the period of laying buds and at the beginning of their blooming.

To maintain decorativeness and prolong flowering, faded buds are removed. Only a few flowers are left for the seeds to ripen, if necessary. In autumn, after frost damage, the cosmea is cut off near the ground, leaving the root in the soil.

Tall plants need support to protect their thin stems from the wind. Also need support for profusely flowering and large-flowered hybrids, which can bend under the weight of flowers. There are several ways to do this. For example, cosmea can be planted often so that the bushes support themselves. Other closely growing plants can also serve as a support. When planting in a group, a stake is driven into the center, and the bushes are additionally tied with twine.

In modern varieties, flowering lasts quite a long time, so the seeds do not ripen at the same time and, moreover, quickly crumble. They are harvested several times per season when they turn brown. Seeds after collection are dried in a dry room and stored in paper bags. One gram contains one and a half to two hundred dry cosmea seeds. Please note: if the package of cosmea seeds next to the name is the F1 icon means you have a hybrid, and collect its seeds for propagation you can’t - you won’t get exactly the same plants.

Although kosmeya is rarely affected by various pests and diseases, it can still be found with viral spotted wilt, powdery mildew and root gall nematode. Of the pests, aphids, snails and slugs can be dangerous.

COSMEA IN THE GARDEN, AT HOME AND IN BOUQUETS

To date, quite a lot of varieties of cosmea with simple, semi-double and double flowers have been created, which differ in height, color, shape of inflorescences (anemone-shaped, pompom, saucer-shaped, chamomile-shaped, with twisted petals). They are planted in a single planting on the lawn or at the gate, used in the design of mixed flower beds, as well as for bouquets. Cosmos with dense foliage are suitable for hedges and backstage, they are very well cut. In addition, double-pinnate cosmos is often chosen for decorating walls or various fences. He is able to create a background for other flower crops. Cosmos harmoniously look in natural-style gardens, attracting butterflies and bees to them.

In addition to the classic (high) cosmos, there are low varieties with a compact bush shape. They are used to decorate borders, the foreground of flower beds, planting in a container. Some of them are suitable for balcony and indoor growing on a sunny windowsill. Cosmea hybrids appeared with abundant flowering or very large inflorescences, brown-violet, lemon and other unusual colors.

For bouquets, cosmea is cut in the morning. The cut is updated daily and the water in the vase is changed. Cut flowers last more than five days.

VARIETIES

Specialized agricultural firms sell various varieties of kosmeya, which grow beautifully in summer cottages and garden plots of our country. Let's give examples of some of them.

Low-growing

Variety "Vega" is a short plant about 30 cm high, having a compact form. Beautiful flowers with a width of 7 to 10 cm are painted in pink, white and reddish hues.

Low bushes up to 30 cm and in terry profusely flowering cosmea "Brightness". This is a mixture of warmly colored cosmies, in a palette of lemon, yellow, orange and red colors. In addition to traditional planting, the mixture is excellent for growing in decorative pots outdoors and indoors.

Medium

Cosmea "Harmony" is presented in snow-white-pink colors. You can distinguish the color of future flowers already at the seedling stage by the color of the leaves. The shape of the inflorescences in this mixture is also the most diverse. Height of bushes 60 cm. Despite the small diameter of flowers (6 cm), more of them are formed on the bush than in traditional varieties.

"White Sonata" attracts attention with strongly branched bushes with openwork branches from 60 to 70 cm high and large inflorescences painted in white. Flowering lasts all summer.

'Pikoti' is a shrub about 80 cm high with highly branched branches. White chamomile inflorescences with a diameter of 10 cm with a carmine-reddish border bloom from July until the first frost.

Tall

Double Click Cranberry Cosmea resembles a red rose with its double inflorescences. The petals, wavy along the edges, are colored with light pink blotches, and the fully opened flower is decorated with a yellow core. The height of this variety is 90 cm.

In the Full Bowl variety, the shape of the flowers is similar to a deep bowl. The fused petals are serrated along the edge of a pale lilac or white color. Height 100 cm.

Learn more