Celery, or Apium graveolens, is a popular garden vegetable. Saving its seed allows gardeners to maintain a desired variety for future seasons. The process is distinct from harvesting the edible stalks and requires understanding the plant’s life cycle. Successfully collecting celery seed involves preparation over two growing seasons, recognizing maturity, and meticulous post-harvest cleaning and storage. This guide walks through the steps needed to obtain viable celery seeds directly from the plant.
Preparing the Plant for Seed Production
Celery is a biennial, meaning it requires two full growing seasons to produce seed. The plant must first experience a period of cold temperatures, known as vernalization, before it can transition from vegetative to reproductive growth. This cold exposure signals the plant to “bolt,” which is the process of sending up a flower stalk in its second year.
To initiate this process, select the healthiest first-year plants with desirable traits to carry over into the second season. In mild climates, plants can often overwinter in the ground. In colder regions, dig them up before the first hard frost. Store the trimmed plants in a cool, moist environment, such as a root cellar, at temperatures between 32°F and 40°F until they can be replanted in the spring.
The vernalization period requires temperatures below 50°F for six to twelve weeks to reliably prompt flowering. Once replanted, the plant focuses its energy on growing a central flower stalk, which branches out into clusters of tiny flowers called umbels. To ensure the seed remains true to type, isolate the seed-producing plants by at least 800 meters. This prevents cross-pollination from other flowering celery or related Apiaceae family members like celeriac.
Recognizing and Collecting the Seed Heads
Seed collection begins when the flower umbels mature and the tiny seeds transition from green to a dry, brown or gray color. This color change indicates the seeds have reached physiological maturity and are ready for harvest. The seeds are small, oval-shaped, and develop vertical ridges, becoming hard when fully ripe.
Celery seed is notorious for shattering, so timing the harvest is crucial to avoid significant loss. The seed head is ready for removal when the majority of seeds on the umbel have turned brown and start to separate with a gentle touch. Cut the entire stalk just below the umbel cluster, as not all seeds on the plant ripen simultaneously.
For the initial drying phase, place the harvested stalks head-down into a large paper bag. Hang the bag in a cool, dry, and well-ventilated location for one to two weeks. The paper bag catches any seeds that fall off the umbels as they continue to dry completely. This ensures the delicate seeds are contained and protected before the final cleaning.
Cleaning and Storing the Harvested Seeds
After the initial drying period, separate the seeds from the remaining plant material, known as chaff. This process, called threshing, is accomplished by gently rubbing the dry umbels between your hands or against a fine-mesh screen to dislodge the seeds. Care must be taken to minimize debris mixed with the seeds.
The next step is winnowing, which separates the lightweight seeds from the remaining chaff. Because celery seeds are very fine, this is often done by carefully pouring the threshed material from one container to another in front of a gentle fan or breeze. The lighter chaff blows away, while the heavier seeds drop straight down into the second container.
Before long-term storage, ensure the seeds are completely dry to prevent mold and spoilage. Store the cleaned seeds in an airtight container, such as a glass jar or sealed envelope, to protect them from moisture and pests. Celery seeds maintain viability best when kept in a cool, dark location, and properly stored seeds can remain viable for planting for up to six years.