Calendula, often known as pot marigold, is a resilient annual flower prized for its vibrant blooms. This annual flower readily produces a large number of seeds, making it an excellent candidate for home seed saving. Collecting your own seed ensures a bountiful supply for the next growing season. This guide details how to successfully collect, dry, and store calendula seeds for long-term viability.
Identifying Mature Seed Heads
A successful harvest begins with identifying a mature seed head, where the seeds have fully developed and dried on the plant. After the bright petals of a calendula flower drop, a round, green seed pod remains on the stem. This pod must completely dry out on the plant for the seeds to reach full maturity.
The seed head changes color from green to a dry, brittle brown or tan, signaling the seeds are ready for collection. If the seed head is still green or moist, the seeds are immature and will not germinate reliably. Collection is best performed late in the growing season, typically from late summer into early fall.
Harvesting the Seeds
Once the seed heads are dry and brown, they are easily removed from the plant. Harvest on a day when there has been no rain for at least 48 hours to minimize moisture content. Use clean snips or scissors to cut the entire dried head off the stem, or simply pinch it off with your fingers. Since the dried heads often crumble easily, collect them in a container like a paper bag or wide bowl beneath the plant.
The calendula seeds are distinctively shaped, resembling curved, spiny commas. To separate them from the dry floral debris, or chaff, gently rub the dried seed heads between your thumb and fingers over a clean surface. The mature seeds readily detach from the remaining plant material. Although a small amount of chaff will not harm the seeds, you can use tweezers to remove larger pieces for a cleaner sample before storage.
Preparing Seeds for Storage
After harvesting, the seeds must be thoroughly dried, or cured, to prevent mold or mildew growth during storage. Even seeds collected on a dry day retain internal moisture that needs to be reduced for long-term preservation. Spread the freshly cleaned seeds in a single, thin layer on a tray, a fine-mesh screen, or a sheet of paper towel.
Place the seeds in a cool, dark, and well-ventilated location, such as a pantry, ensuring they are out of direct sunlight. Allow the seeds to dry for one to two weeks; this extended period ensures the moisture content is low enough for dormancy. To test for dryness, press a seed with your fingernail; a fully dried seed should feel hard and snap or shatter rather than bend.
Storing Calendula Seeds
Proper storage conditions are necessary to maintain seed viability until the next planting season. The ideal environment is consistently cool, dark, and dry, with low humidity. Suitable containers include small paper envelopes, glassine packets, or airtight glass jars.
Paper envelopes are often favored as they allow for slight air circulation, safeguarding against residual moisture. Regardless of the container, clearly label each batch with the date of collection and the specific variety. Stored under these conditions, calendula seeds typically remain viable for one to two years. For maximum longevity, the labeled containers can be placed in a refrigerator, as the low temperature slows the seeds’ metabolic rate.