FAIRFIELD COUNTY, Conn. -- If you missed the opportunity to plant live plants this fall, you still have a late season option – seeding with certain native plants. Live plants are ideally planted 6 to 8 weeks before hard frost to insure successful root establishment before the frigid weather sets in. In contrast, the typical colder weather of November and December rules out the chance for seed germination and offers a perfect time to plant seeds that need a dormant period.
Seeding is a very inexpensive way to grow native plants, but it does require a bit of strategy. Not all seeds germinate in the same way, nor are all plants available as seed. Some seeds require a pre-treatment like stratification – an extended period of moist, cold conditions. With such seeds, fall or early winter planting provides these conditions and the seeds will typically germinate in the spring.
To plant native seeds successfully, the first step is to determine what the germination requirements are for a given plant. Fortunately, there are some excellent resources available. The invaluable book, Wildflowers: A Guide to Growing and Propagating Native Flowers of North America, written by William Cullina, includes the germination requirements for many native perennials. A helpful online resource is the Prairie Moon Nursery website that includes the guide: How to Germinate Native Seeds.
Tips for Successful Late Seeding
Select seeds that require a moist, cold period and that meet the conditions of your site. Some candidates might include Spiderwort, False Aster, Coreopsis, Blue Flag Iris, and White Turtlehead. Wait until spring to seed warm season grasses.
Eliminate weeds in the area to be seeded, otherwise cool season weeds may overwhelm any new seedlings in the spring.
Seed into bare soil and ensure good seed-to-soil contact. This is important for germination and reduces the chance that birds and small mammals will feast on the seeds. Press the seed into the soil with your hands or gently step on the seeded area. For large areas you can use a water-filled roller.
Plant seeds at the appropriate depths. Some seeds need to be planted more deeply or shallowly than other. If planted too deeply, a seed may not germinate at all.
Mulch the seeded area to protect the seed and to retain moisture in the soil. Straw that is weed-free and seed-free can work well, but don’t mulch too deeply.
Seeding can also be done in early winter over frozen soil, after the first killing frost but before the first snowstorm. During the winter, the seed will settle in through the action of frost and make contact with the soil. Hungry critters may get to the seed first.
Be patient and don’t give up – while many seeds will germinate in the spring, some can be stubborn and take year or more to germinate.
Kim Eierman, a resident of Bronxville, is an environmental horticulturist and Founder of EcoBeneficial . When she is not speaking, writing, or consulting about ecological landscapes, she teaches at the New York Botanical Garden, Brooklyn Botanic Garden, The Native Plant Center and Rutgers Home Gardeners School.
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