Chrysanthemums, often called mums, are popular fall-blooming plants belonging to the Asteraceae family. While many varieties are propagated through cuttings or division, some species and older cultivars produce viable seed. It is important to understand that many modern, showy chrysanthemums are complex hybrids that yield sterile seeds or offspring that do not resemble the parent plant. Successful seed saving begins with recognizing a viable bloom and preparing for the careful process of collection and preservation.
Identifying Mature Seed Heads
Chrysanthemum flowers must complete their entire bloom cycle, where the petals first fade and then drop away. This process reveals the central disc florets, where the tiny achenes, or seeds, develop. The flower head should transition from green or vibrant color to a completely desiccated, brown, or tan structure.
The entire stem directly beneath the flower head should also appear dry and brittle. This signals full seed maturity, indicating the plant has ceased sending moisture and nutrients to the head. Harvesting immature, green seed heads results in non-viable seeds, as they cannot ripen once removed from the parent plant. The best time to check for this readiness is typically in the late fall, often after the first light frost.
The Physical Collection Method
A warm, sunny day is the ideal time to harvest, as any lingering moisture can compromise the seeds during storage. Using clean, sharp scissors or small pruning shears, carefully snip the dried flower heads from the plant. Cut the stem a few inches below the head to provide a small handle for easy handling.
Collect the entire dried head material, including the remaining chaff and small stems, into a breathable paper bag or a wide, shallow container. Avoid using plastic bags, as they can trap residual moisture and encourage mold development. Immediately label the container with the variety name and the date of harvest. Transporting the material indoors promptly prevents the dried achenes from scattering.
Cleaning and Curing the Seeds
The next step involves separating the seeds from the surrounding botanical debris, known as chaff. Gently crush the dried flower heads between your hands or rub them over a fine mesh screen to release the seeds. You can use winnowing, which involves slowly pouring the mixture from one container to another in front of a gentle fan. The lighter chaff will be blown away, leaving the heavier seeds to fall straight down.
After separation, the seeds require curing to reduce their internal moisture content. Spread the cleaned seeds in a single layer on a paper plate, screen, or newspaper in a cool, dark, and well-ventilated area. Allow them to dry for approximately one to two weeks, ensuring they are protected from direct sunlight. Proper dryness is achieved when a seed cannot be indented or bent with a fingernail, indicating a low moisture level that prevents rot.
Storing Seeds for Future Planting
To maintain viability, the cleaned and cured seeds must be placed in a stable, dormant environment. The ideal conditions for storage are cool, dark, and dry, with consistent temperature and low humidity. Sealed glass jars or small paper envelopes placed inside an airtight container work well for home storage. A small packet of silica gel or powdered milk inside the container can help absorb any remaining atmospheric moisture.
Store the sealed container in a location like a refrigerator or a cool basement, where temperatures remain steady. Always label the container clearly with the chrysanthemum variety and the date of collection to track its age. Chrysanthemum seeds generally retain good viability for two to three years when stored under these controlled conditions.