Lobelia plants are valued in gardens for their small, vibrant flowers and cascading growth habit, making them popular choices for containers and hanging baskets. Saving the seeds is a practical way to ensure a supply of your favorite variety for the following season without the recurring cost of buying new seed packets or seedlings. This process also allows you to preserve specific traits, like flower color or growth pattern, that you admire in your current display. Successfully collecting and storing Lobelia seed requires careful observation, precise techniques, and maintaining ideal environmental conditions to keep the tiny seeds viable for future planting.
Timing the Seed Harvest
The successful collection of Lobelia seeds begins with correctly identifying when the tiny seed capsules are fully mature. After the blossoms fade, Lobelia flowers develop into small, spherical or oval seed pods that must be completely dry before harvesting. An immature pod will be green or cream-colored, indicating the seeds inside are not yet fully formed or ready for dormancy.
Wait until the seed pods have transitioned to a light tan, brown, or blackish color and feel dry and crispy to the touch. This change signals that the moisture content has dropped sufficiently for long-term storage. Since Lobelia species flower from the bottom of the stalk upward, the lowest pods on the stem typically ripen first. Monitor the plant closely, as mature capsules can easily split open, allowing the minuscule, dust-like seeds to scatter and be lost before collection.
Physical Collection Methods
Specialized methods are necessary to prevent Lobelia seeds from being lost during collection due to their small size. The most effective technique involves cutting the entire flower stalk containing the ripe seed capsules. Work over a clean, light-colored surface, such as a white plate, sheet of paper, or shallow container, which provides a high-contrast background to help you see the seeds.
Once the stalks are cut, place them upside down into a paper bag or jar, or hold them over your collection surface. Release the seeds by gently shaking the stalk or by carefully crushing or rubbing the brittle seed capsules between your fingers. A small, fine-mesh kitchen strainer can also be used to rub the dry seed pods against, allowing the seeds to fall through while retaining larger debris.
Cleaning and Curing Seeds for Viability
After collection, the raw material consists of seeds mixed with fragments of dried flower and pod material, known as chaff. Chaff must be separated from the seeds because it can trap moisture and promote mold growth during storage, reducing viability. For Lobelia’s fine seeds, winnowing can be performed by gently blowing across the collected material. The lighter chaff will lift and blow away, while the heavier seeds remain on the surface.
Following separation, the cleaned seeds must undergo a curing or thorough drying period to remove any residual moisture. Spread the seeds thinly in a single layer on a non-porous surface, like a ceramic plate or glass tray, and leave them in a cool, dry location away from direct sunlight for one to two weeks. Ensuring the seeds are completely dry is essential, as a low internal moisture content is directly linked to maintaining the seed’s dormant state and extending its longevity.
Long-Term Storage Conditions
The longevity of Lobelia seeds depends entirely on providing a stable environment that is cool, dark, and dry. Heat and humidity are the two primary factors that cause seeds to prematurely break dormancy or decay, so minimizing their exposure is paramount.
Once the seeds are fully cured, place them in an airtight container to seal out environmental moisture. Small paper or coin envelopes are good primary containers because they allow a tiny amount of air exchange, but these should then be sealed inside a secondary barrier, such as a glass jar or a sealed plastic bag. Labeling the container with the Lobelia variety and the date of harvest is important for tracking viability over time. Storing these sealed containers in a refrigerator provides the ideal cool, dark conditions that maximize the seed’s lifespan.