The Cardinal Flower (Lobelia cardinalis) is a striking perennial native to the Americas, celebrated for its brilliant, deep crimson flowers. These vivid red blooms grow on tall spikes, making the plant a beacon for pollinators like hummingbirds throughout late summer and early fall. For gardeners interested in propagating this magnificent plant, understanding the nature of its seeds is the first step toward successful cultivation.
Identifying Cardinal Flower Seeds
Cardinal Flower seeds are notably minute, often described as being nearly dust-sized due to their extremely small scale. These seeds are significantly less than one millimeter in size, making them challenging to handle without proper care. The shape of the individual seed is irregular, sometimes appearing ovate or granular. Their color is typically a light reddish-brown, tan, or light brown. Hundreds of these tiny seeds are packed within small, two-celled capsules that form along the central flower stalk after the blooms fade.
Collecting and Starting the Seeds
The seeds develop within small, green-to-brown capsules that mature along the stalk after flowering. The ideal time for collection is late summer or early fall, typically September or October, once the capsules have fully dried out and are just beginning to crack open. Cut the stalks containing the pods and allow them to dry further, often by placing them upside down in a paper bag for about a week.
Collecting the seeds requires a delicate approach because of their powder-like nature. After drying, release the seeds by gently shaking the stalks or lightly crushing the dried capsules over a paper plate or a fine mesh kitchen strainer. The strainer helps separate the minute seeds from the larger, unwanted plant debris, known as chaff.
Once collected, the seeds require surface sowing, meaning they should be sprinkled directly onto the surface of moist, fine-textured potting mix and not covered with soil. This is because the seeds are photoblastic and need light exposure to initiate the germination process. To break dormancy, many sources recommend that Lobelia cardinalis seeds undergo cold stratification. This treatment involves keeping the seeds moist and cold, typically below 40°F, for 30 to 60 days before moving them to a warmer environment to sprout.