Coreopsis are grown from seed. They can be directly seeded into your flower garden in early spring. Sow Coreopsis seeds early in the season, covering lightly with coarse or sandy soil. Keep the soil moist until they germinate, about one of two weeks. This will break seed dormancy and increase germination of many native wildflowers. … Most prairie grasses do not require Moist Stratification for good germination. It is not necessary to use this pre-treatment for seed that is to be planted in the fall, as dormancy will be broken naturally in the soil over winter.