You can buy the Cosmea or sow it if you want to bring these plants into your garden. Buying is easier, but sowing is also relatively easy to do and is also a lot of fun.

The seeds can be collected from old plants in autumn

If you use seeds that you have collected from old plants, then you are working with a "lucky bag", so to speak, because you do not know which genetic traits of the parent plants will prevail in your young plants.

Sowing indoors

In March or April the time has come to sow the cosmea on the windowsill or in the warm greenhouse. Fill a container with nutrient-poor growing substrate or soil mixed with sand. Then sprinkle the small seeds on top and some soil on top.

Moisten the whole thing carefully and regularly with a water spray and place the culture vessel in a warm place, preferably on the windowsill. At around 20 °C, the first seedlings will appear after around 14 - 21 days.

Sowing outdoors

If you would like to sow the cosmos directly outdoors, you will have to wait until mid or late May. Ideally, sow after the ice saints so that your seedlings do not freeze. Again, the soil should be low in nutrients and kept evenly moist. However, the beginning of the flowering period is postponed by a few weeks, as the plants have to grow up first.

Undesirable propagation by self-seeding

In contrast to the plants, the seeds of the cosmea are hardy. They tolerate frost and will germinate easily next spring. New cosmeen often grow unplanned at the old location, even if this bed is now intended for other plants. Weeding can be a nuisance at times. However, you can also simply relocate the unwanted plants to another location.

The essentials in brief:

  • very small seeds
  • Self-sowing frequently
  • Seeds can be collected and dried
  • Sow indoors from the end of February
  • Outdoor sowing from mid-May
  • only cover thinly with soil or substrate
  • Germination temperature: approx. 20 °C
  • Germination time: 14 - 21 days

tips

If you want your Cosmea to flower early, then you should prefer the young plants indoors and not sow them outdoors.

Category:

Herbs