How to propagate Cosmos

sowing

Cosmos planting season

The seeds of Cosmos have the ability to self-sow. Once planted, they will produce a large number of self-sowing seedlings. If they are slightly protected, they will bloom as usual. It can be sown in the open field in mid-April. If the temperature is suitable, the seedlings will emerge in about 6 to 7 days.

If sown in July-August, the seeds will bloom in October and the plants will be short, strong and neat.

Cosmos seedling maintenance

Cover the seeds with about 1 cm of soil and the seedlings will emerge in about 5 to 10 days. Transplant the seedlings when they have 4 to 5 true leaves and pinch off the tops. You can also seed directly and then thin out the seedlings. If base fertilizer is applied to the planting site, no further fertilizer is needed during the growing period. If the soil is too fertile, the branches and leaves will tend to grow too tall and the flowering will decrease.

Those that bloom during the high temperatures of July and August are unlikely to bear fruit. The seeds fall off easily after they mature, so they should be collected in the early morning. Cosmos is a short-day plant. Spring-sown seedlings often have lush leaves and few flowers, while summer-sown seedlings are short, neat, and bloom continuously.

Cuttings

How to propagate cosmos by cuttings

Cosmos cuttings should be taken in the warm month of May and will bloom in June and July.

You can choose thick top branches, cut a 8 cm to 10 cm long section as cuttings, and plant 3 to 5 plants in a cluster in a flowerpot. The pot should be buried in the soil, with 4 cm to 5 cm exposed above the ground. Water and shade it, and it will take root after half a month.

Cosmos cutting maintenance

After the cuttings have taken root, apply thin fertilizer solution once every 15 days. When they grow to 15 cm, remove the top buds to promote more branches. If fertilizer and water are controlled properly, flowers will be seen in about 45 days.

Whether it is a sown seedling or a cutting seedling, a certain degree of dwarfing is required to avoid the situation of falling over in the wind after the plant is formed.

When topping and pinching the branches, make sure the pruning tools are sharp and the cuts are even. The newly grown terminal buds can be removed several times in a row, and the plant will become short, strong and healthy.