How to Propagate Hostas From Seed
Hostas are a favorite shade-loving plant of gardeners in the United States, prized for their beautiful foliage. Hostas are most commonly propagated by dividing mature plants. They can be grown from seed, but because of hybridization, hosta seed collected from mature plants most often does not grow to resemble the parent plant. If you would like to grow hostas from seed, plan to start the process in January in order to transplant the seedlings outdoors in the spring.
Refrigerate the seed until January. This preserves the seed and simulates winter conditions.
Fill a shallow plastic tray designed for seedlings with a loose potting soil designed for seedlings. The soil should be level with the top of the tray, not packed in too tight.
Water the soil in the tray with a watering can with a perforated sprinkling cap to avoid disturbing the soil. Dampen the soil thoroughly.
Scatter roughly 1 tbsp. of seed across the top of the damp soil. Pat down lightly.
Mist the seed daily to keep it moist. Keep the tray in a warm spot, where the temperature is between 65 and 75 degrees.
Move the tray to a sunny window or beneath a grow light when seedlings emerge.
Remove any weak or unattractive seedlings. When the remaining plants have three true leaves, transplant to 2-to 3-inch diameter seedling pots. Plant in the pots in the same potting soil you used for the seedling trays.
Continue to mist the plants daily to keep the soil moist. Turn them often to help them grow straight.
Transplant the seedlings into the garden when all danger of frost has passed. Dig a hole with a trowel the same size and depth as the seedling pot and plant the seedling at the same depth it was in the pot. Tamp the soil lightly around the seedling and water thoroughly.