Growing from Seeds

What Do I Do With My Seeds?

Growing native plants from seed can be fun and rewarding. It is also an inexpensive way to add native plants to your garden. At several recent events, we shared seeds of several species harvested from flowers grown in our own gardens here in Lexington. Here is some follow-up advice that may prove helpful.

What do I do now? The seeds we distributed are all from local native plants, adapted to our local environment. These seeds typically need a period of cold and wet conditions (called cold stratification) before they’ll germinate. This helps to ensure that they won’t germinate in the fall and then die in winter’s cold. There are three ways to achieve the cold they need:

1. You can sow them in your garden this fall; that, after all, is what nature does. Make sure there’s good seed-to-soil contact. Larger seeds will benefit from a thin soil cover, but the smaller seeds need to be at or very close to the surface to catch some sun. Some of the seeds will be eaten by wildlife, but hopefully some will survive to germinate in the spring.

2. You can place them in your refrigerator, in a plastic bag with a damp paper towel, for artificial cold stratification, and then sow them in the spring. See the websites below for detailed instructions on cold stratification.

3. To improve your success rate, many species can also be grown in pots for later transplant into the garden. Leave the pots outside through the winter in a shaded area where they’re exposed to the rain and snow but protected from hungry critters.

For more information about cold stratification and for more details about growing some of the species listed below, two helpful sources are:

Wild Seed Project (

Prairie Moon Nursery (

Below are brief descriptions of the species we distributed at recent events and their preferred conditions.

Partridge Pea (Chamaecrista fasciculata)

is an annual plant native to most of the eastern U.S. It grows to about 2 feet high, with an abundance of cheery yellow flowers in the latter half of the summer that are magnets for bees. Many native plant gardeners like it as a “bridge” plant, helping suppress weeds and fill in spaces between perennials until the latter become well established. Sow it directly in late fall or early spring; it does best in sunny locations with a little bit of soil or mulch over the seeds to retain moisture. In the packets we distributed are a dozen or so seed pods; some may have already opened, but otherwise just pop them open and the seeds will fall out.

Common Milkweed (Asclepias syriaca)

is one of the easiest and fastest of the milkweeds to grow, and once established, spreads readily by seed and underground rhizome, leading some to warn about its aggressiveness. It does best in full sun or partial shade in medium to dry soils, growing 3-4 feet tall with large white to purple flowers appearing June–August. Milkweeds are the only host plant of Monarch caterpillars.

Butterfly Weed (Asclepias tuberosa)

is another milkweed with beautiful orange blossoms that bloom through the summer. Shorter than Common Milkweed at around 2 feet tall, it has similar sun and moisture requirements, and is particularly well adapted for dry sites.

Swamp Milkweed (Asclepias incarnata)

has small lovely pink to purple flowers clustered in inflorescences. Growing 2-4 feet tall, swamp milkweed prefers sun or part shade and moist to wet soils, though it will also do well in medium, well-drained garden soils.

Cardinal Flower (Lobelia cardinalis)

grows up to 4 feet tall and is found in wet places, streambanks, and swamps in full sun or partial shade. The flowers are usually vibrant red and display the characteristic “lip” of Lobelia species. While perennial, they are usually short-lived but readily self-seed. In each packet you’ll find several seed heads; dump the envelope out over a sheet of white paper, break open the seed heads, and the tiny red seeds (more than 6 million to the pound!) will spill out.

Foxglove Beardtongue (Penstemon digitalis)

grows up to 3 feet tall and has white blooms in June and July. It prefers full sun or partial shade, and does well in medium to medium-dry soils. In each packet you’ll find several firm seed heads; break them open with your fingernail or a knife (be careful!) and the seeds will fall out. Not as tiny as the seeds of Cardinal Flower, but still small (over one million to the pound).

Joe-Pye Weed (Eutrochium purpureum)

grows up to 6 feet tall in the best sun/soil conditions, but strong stems support the flowering plant so it rarely needs to be staked. These attractive stems are almost the same color as the dusty rose-colored flowers, which will bloom for many weeks in July and August, becoming magnets for dozens of species of butterflies. Also called Spotted Joe Pye Weed, it is best planted in full to almost-full sun and rich, moist soils. It will spread so should be planted with caution in small garden situations.

Carolina Lupine (Thermopsis villosa)

is an upright clumping perennial with bright green clover-like foliage, it grows up to five feet tall. In early summer, plants are topped by spires of buttery yellow pea-shaped flowers. Plants thrive in sunny gardens with average well-drained soils and are durable and long-lived after establishment. Bees and butterflies seek nectar and pollen from the flowers.

If you have questions, don’t hesitate to reach out to us and ask; we’re at

An additional note: Native plant flowers provide nectar and pollen for pollinators and their leaves serve as food for many kinds of insects. These insects, in turn, become food for birds and other small animals. However, please note that many plants produce chemical defenses against insects and other animals that would like to eat them, and some are harmful for children and pets to eat too. If you have a young child or pet who might be inclined to ingest your garden plants, you can learn which ones present a hazard at a number of websites like this one.