Planting and caring for cosmos
No garden should be without these summer flowers!
I have a special relationship with cosmeas, also known as Mexican aster: They were the first flowers I grew from seed. I remember my excitement when the first green was actually visible after just a few days. To this day, I still consider cosmos to be one of the most beautiful, robust annual summer flowers that no garden should be without. They now come in fantastic colours such as apricot or peach and exude a lascivious, wild charm wherever they are planted.
The most important facts in brief
- cosmos are particularly easy to grow & are ideal for garden beginners
- annual cut flower
- sow indoors from February, in the garden from May
- direct sowing in autumn or early spring
- pinching for higher flower production
- regular pruning stimulates bud formation
- suitable for beds, containers and pots
- insect pasture
Sowing cosmeas
You can start sowing cosmos indoors as early as March.
A warm, bright and sheltered location, such as a windowsill, is best suited for this. Cosmos love warmth. The ideal germination temperature is 18-24°C. Always keep the soil moist, especially if you are growing cosmos in a very sunny spot. The first seedlings will appear after about 7 days and you can look forward to the splendour of the flowers.
Direct sowing in the garden is possible from May (as soon as the soil is frost-free!). You can then place the seeds in the soil at a planting distance of approx. 20-25 cm. The same applies here: Moisten regularly!
It takes about 75-90 days from sowing to flowering.
Location & soil
Cosmos love light and need a sunny location to fully develop their flowering splendour. The soil should be well-drained and you should ensure even moisture. Avoid waterlogging at all costs, otherwise the plants will die within a very short time.
Cosmos are equally at home in beds, pots and containers, so you can be enchanted by them in the garden, on the patio or on the balcony.
Caring for cosmeas
Hardly any other cut flower is as easy to care for and productive as the cosmos. Once planted, you can enjoy months of blooming splendour without much effort. When the small plants reach a height of around 20-30 cm, don’t hesitate to pinch them out (shorten the main shoot by 10-15 cm). Even if it is difficult at first, it is worth it and you will be rewarded with an even richer abundance of flowers.
Keep cutting off wilted plants during the flowering period to stimulate bud formation and you will be rewarded with an endless sea of flowers. And that until early autumn!
Cutting cosmos for the vase
The cosmos are an absolute eye-catcher in a vase and bring summer to the table. You should harvest them when the buds are just beginning to open. For double cosmos varieties, it is advisable to wait until the buds are half open. You can enjoy the freshly cut cosmos in a vase for up to 7 days.
