Cosmos flowers are easy to grow and will bloom throughout the summer months. To ensure that you have plenty of Cosmos flower blooms for your garden, it is important to harvest their seeds at the end of each season. With proper seed preparation and storage, you can enjoy beautiful Cosmos flowers year after year.
When to Harvest Cosmos Seeds
If you want to get Cosmos seeds, leave the largest buds on the bush for fruit ripening, and to prevent the ripe seeds from spilling on the ground, put gauze bags on the flower heads. As soon as the seeds become dark in color, it is time to remove them. However, it is worth knowing that Cosmos is a cross-pollinated plant, so the seeds do not retain varietal characteristics, and it makes sense to simply buy seeds from well-established manufacturers.
How to Harvest Cosmos Seeds
When the flower heads are ready to be harvested, cut or pluck them off and put them in paper bags. Hang them upside down in a well-ventilated area until they completely dry out. Once the Cosmos seeds are entirely dry, you can easily remove them from their capsules with your fingers and place them in an envelope or small container.
Seed Preparation for Storage
Before storing your Cosmos seeds, it’s important to make sure they are completely dry and free of any debris. The best way to do this is to spread the seeds out on a paper towel and pick out any bits of chaff or other unwanted material. After that, you can place the clean seeds in an airtight container such as a glass jar or zip-top bag.
When storing Cosmos seeds, it’s important to keep them in a cool and dry place. The ideal temperature for seed storage is between 40°F (4°C) and 50°F (10°C). Seeds should also be stored away from direct sunlight, in a dark location if possible. It is also a good idea to include a desiccant packet in the container, such as Damp-Rid or silica gel, which will help absorb any moisture that may be present.
Shelf Life Cosmos Seeds
The longevity of your stored Cosmos seeds will depend on how well you maintain their environment and conditions. Properly stored, they should remain viable for at least three to five years. You should keep an eye on the moisture content of your stored seeds, as too much moisture can cause mold or fungus to develop. If you detect any signs of this growth, discard the affected container and its contents immediately.