October 10, 2024, 11:36 am | Read time: 5 minutes
With its bright shades of pink and elegant white, cosmos is easily recognizable from afar. Find out here how you can showcase this delicate summer flower from South America in your garden.
Its basket-shaped flowers and simple beauty have earned cosmos bipinnatus the charming German name ‘Schmuckkörbchen,’ which translates to ‘jewel basket.’ It is also known as the common cosmos, garden cosmos, or Mexican aster. This delicate plant, with its bright colors, is one of the most beautiful summer flowers in our gardens. It looks particularly good in cottage gardens and country house gardens. Cosmos is a species from the cosmos genus, which itself belongs to the composite family. It originates from Mexico and Brazil.
Overview
Appearance and growth
Cosmos is an annual, upright-growing, and richly branched summer flower that can reach heights of 20 to 47 inches, depending on the variety. Its finely feathered foliage is somewhat reminiscent of dill. The pink, purple, red, or white flowers, which are up to eight centimeters in size and have a yellow center, appear in July. The flowering period lasts until October. Newer varieties also flower in two colors, yellow or partially double.
Sowing and planting cosmos
Cosmeas can be grown indoors starting at the end of March. After the Ice Saints, when frost is no longer expected, the young plants can be moved outdoors. If you don’t want to grow them indoors, you can also sow the flowers directly into the bed in April and May. Whether indoors or outdoors, the seeds should only be covered with about half a centimeter of soil, and they must not be allowed to dry out. Instead of reaching for the seed packet yourself, you can, of course, also buy them pre-grown and plant them out from mid-May.
Location and soil
Cosmos thrive best in a sunny location. It can also grow in partial shade but will then flower less. The soil should be loose, well-drained, humus-rich, and moderately nutrient-rich.
Cosmos is at its best when planted in small groups of three to five plants. However, they should not be planted too densely, as they grow quite sprawling. A distance of around 30 centimeters is fine.
Cosmos can be paired with other summer bloomers. Sunflowers, cornflowers, zinnias, dahlias, phlox, mallow, delphiniums, and marigolds are particularly suitable as bedding partners.
These attractive plants also do well in containers on balconies or patios. Drainage ensures that the plants do not get wet feet. The plants do not like waterlogging at all.
Cpsmos variety tips
There are a large number of varieties of Cosmos bipinnatus:
- ‘Sensation Mix’ has a wide range of flower colors, from white to pink to magenta.
- ‘Dazzler’ blooms crimson pink and grows up to 120 centimeters high.
- ‘Rubenza’ has ruby red flowers that fade to dusky pink over time.
- ‘Sea Shells’ have very special flowers. Each petal is curled in on itself.
- ‘Radiance’ is a particularly sturdy variety. It has bright pink petals that become darker towards the center of the flower.
- ‘Xanthos’ is a new variety. It flowers in a delicate yellow and does not grow taller than 50 centimeters.
Cosmos care
Cosmos are easy to care for and robust. As they sometimes have a tendency to fall over, they can be supported with a stick if necessary. Read on to find out what else you need to do.
Watering
If the cosmos has grown well, it can also cope well with temporary drought. The watering can will have to be used if it stays dry for too long. If the plant grows in a container, it must be watered regularly.
Fertilizing
If the cosmea grows in good garden soil, it does not need fertilizer.
Pruning
There are two reasons why cosmos is pruned: Firstly, to increase the plant’s willingness to flower. If you regularly cut off withered flowers, more flowers will form. Secondly, cosmea is a wonderful cut flower that will keep in a vase for around five to seven days.
Propagation
To propagate ornamental cosmos, use the seeds. You can find out how to sow them in the “Sowing and planting Cosmea” section above. If the plant feels at home in the garden, it will reseed itself. If you don’t want to rely on self-sowing, you can collect the seeds from the dried inflorescences, save them, and sow them again in a suitable place the following year.
Overwintering
Cosmos are annuals, so there is no need to worry about overwintering. The plants die in the fall when temperatures cool.
Toxicity
The ornamental basket is non-toxic.
Alternatives to cosmos
In addition to the cosmea (Cosmos bipinnatus), there are many other species in the cosmea genus that are suitable for the garden. One is the perennial but not hardy chocolate cosmea, also known as the chocolate flower (Cosmos altrosanguineus). The plant owes its name to its chocolaty scent. Particularly fragrant is the variety ‘Chocamocha’. The annual species cosmos sulfurous, also known as yellow cosmos or sulfur cosmos, has yellow and orange flowers.
The annual spider flower (Cleome spinosa) is also a good alternative to cosmos. It grows to a similar height and also flowers in white, pink, and purple.
Bee friendliness
Bees, bumblebees, hoverflies, and butterflies are attracted to cosmos flowers in large numbers. Birds like to eat the seeds.
Diseases and pests
The jewel basket is very robust. Its biggest problem is snails, which mainly prey on young plants. A snail collar can help in the early stages.
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Harvesting and use in the kitchen
The petals can be harvested at any time. They taste slightly sweet and are ideal for decorating desserts, salads, and soups.