Digitalis purpurea, commonly known as foxglove, is a striking plant characterized by its tall spires of bell-shaped flowers. Gardeners collect its seeds primarily for propagation, allowing for the cultivation of new plants for the following season. Every part of the foxglove plant is toxic due to the presence of cardiac glycosides like digoxin and digitoxin. Because ingestion can cause severe side effects or death, always wear protective gloves when handling the plant, including the stems, capsules, and seeds, and wash your hands thoroughly afterward.
Determining When Seeds Are Ripe
Successfully collecting viable foxglove seeds depends on harvesting at the correct stage of maturity, typically in late summer or early autumn. After the tubular blossoms fade, they are replaced by small, green seed capsules that swell as the seeds develop inside. The seeds must be allowed to mature completely on the plant.
The most reliable sign that the seeds are ready is a distinct change in the capsule’s appearance and texture. The pods will transition from green to a dry, brittle, light brown or tan shade. You may also notice the capsules beginning to crack open slightly, or hear a subtle rattling sound if you gently shake the stalk. Since flowers mature from the bottom of the spike upwards, the lowest capsules will be ready to harvest first.
Techniques for Collecting Foxglove Seeds
The collection process requires careful attention because the fine seeds can be easily lost once the dry capsules split open. To prevent spillage, place a container, bucket, or paper bag directly beneath the section of the stalk you intend to cut. Use sharp, clean shears to snip the portion of the stalk containing the dry, brittle capsules, ensuring the severed section falls immediately into the container.
Alternatively, harvest individual ripe capsules by pinching them off the stalk directly into a container, working from the bottom up. Once collected, extract the seeds by gently shaking or tapping the seed heads over a smooth surface, such as a tray or paper. Placing the dried capsules inside a sealed jar and shaking vigorously is an effective method to dislodge the fine seeds. Remember to wear protective gloves throughout this handling process.
Preparing and Storing the Seeds
Proper preparation is necessary to ensure the seeds remain viable and do not develop mold during storage. Immediately after separating the seeds from the remaining plant material, they must be thoroughly dried, even if they appeared dry when collected. Spread the seeds in a thin layer on a clean sheet of paper, a tray, or a fine screen. Place them in a cool, dark, and well-ventilated area for several days.
Once completely dry, move the seeds into an airtight container to protect them from moisture and pests. Small glass jars or wax-coated paper envelopes are suitable options for long-term storage. Label the container clearly with the type of foxglove and the collection date. Storing the sealed container in a cool, dark, and dry location, such as a refrigerator, will maintain seed viability until the next sowing season.