The Best Time to Plant Rudbeckia Hirta Seeds

Plant Life Cycle

• Gather seeds of black-eyed Susan if you wish to maintain a cluster of plants in a certain area of the garden. The seeds naturally drop and scatter around a landscape, sprouting wherever conditions are favorable. In very cold winter and hot-summer regions, black-eyed Susan grows as an annual. In milder climates the plants die back to the roots in winter but sprout back for a second or third year. Repeated blooming increases the number of seeds available to ensure more plants begin and continue in subsequent years.

Sowing Time Frame

• The best time to sow black-eyed Susan seeds is in early spring, after the seeds have been stratified. Stratifying is exposing the seeds to a cold treatment, which is required before the seeds will germinate. This may be accomplished in a refrigerator for 90 days or storing the seed in an unheated shed or garage over the winter. Sow the seeds as early as possible in very late winter or early spring, as soon as the soil is workable. If seeds are started indoors, sow them eight weeks prior to the expected last spring frost date in your area.

Fall Planting Insight

• In mild winter areas, black-eyed Susan seed may be scattered atop the soil in autumn. They will sprout once the cool nights stratify the seeds and lead to germination. In the Desert Southwest, Hawaii and southern Florida, fall seed sowing is better than spring sowing. Germination occurs in midwinter, leading to healthy plants that bloom before the onset of oppressive summertime heat. Farther north, where winters are much colder, wait until spring to sow seeds. Too many variables such as wind and snowcover exist in northern climes that may cause fall-sown seed to rot, wash away or dehydrate.

Seed Information

• Approximately four weeks after opening, the faded black-eyed Susan flower yields ripe seeds ready for harvest. The old central disc of the bloom is called the nutlet, and becomes charcoal-gray at maturity. Pluck the nutlets and store in a container after they fully air-dry. However, seeds are easier to collect if the nutlet further dries and expands to release the seeds.The tiny seeds drop out of the nutlet or may be crushed out. Sow seeds in a fine-textured, moist but well-drained soil at a depth of 1/8 inch to 1/4 inch. Seeds germinate, after the required cold stratification treatment, in one to two weeks.