It’s easier than many people think to grow large numbers of native plants from seed. Now is the perfect time.
Removing invasive plants, whether by cutting or uprooting, disturbs the soil and gives invasive seeds access to the sun and moisture they need to germinate and grow. Invasives have durable seeds that rest in soil for years before sprouting. It can be discouraging to dutifully chop down a gloriously red but invasive burning bush (Euonymus alatus) or Japanese barberry (Berberis thunbergii) and still have to pull out seedlings a decade later.
It’s good to cover all that bare soil with natives, preferably many. But that can be expensive, one nursery plant purchase after another. Sowing seeds from owned or carefully collected native plants is an affordable way to grow hundreds of natives. There are two main strategies, outdoors and indoors.
Outdoors Strategy
The Wild Seed Project, a non-profit based in Maine, collects seeds and makes them available. It also offers great step-by-step guidance on propagating by seed outdoors—wildseedproject.net
Gather seeds, label carefully, allow to fully dry in paper bags.
Fill 4–6” pots with organic, compost-based potting soil and pat down.
Sow seeds thickly; cover with coarse sand in a layer as thick as the seeds (almost none for tiny seeds); water thoroughly and gently.
Put the pots outdoors, in a shady spot, protected from rodents with a metal screen.
Leave them alone to enjoy winter; look for signs of germination starting in March.
Water regularly in the spring and transplant to larger pots as they grow.
Plant based on their preferred conditions – sun, moisture, etc.
Closer to home, the Granby Wildflower Meadow (five acres on Rtes. 10/202, less than a mile south of the center) offers native wildflower seed mixtures and easy instructions for a third strategy, bare-ground sowing (GranbyWildflowers.org/wildflower-seeds). President Aubrey Schulz presented “Unravelling the Mystery of Seeds,” a terrific Granby Library presentation in August; it can be viewed at GCTV16.org/viewshows/publicaccessshows
Indoors Strategy
The indoors strategy is more plant-specific. Germination Codes describe how specific seeds should be treated to mimic the conditions they need in the wild—like “sow anytime (A)” or “cold stratify for 60 days (C-60).” Codes for hundreds of native plants are often available from seed sources like Prairie Moon Nursery (Prairiemoon.com); a voluminous list assembled by plant scientist William Cullina is available on UConn’s excellent seed propagation resource page (CIPWG.uconn.edu/propagating-from-seed-resources).
Gather seeds, label, dry in paper bags.
Look up the germination code for each seed and add to the label.
Cold stratify by mixing the dry seeds with moistened sand or sterile potting soil, or place between damp folded coffee filters or paper towels. Place each set of seeds into small plastic bags with labels that include the dates when they should be removed. Put the bags in a cool place such as the back of a refrigerator drawer.
When their cold stratifying period has ended, sow the seeds indoors in trays or pots, under lights or in a sunny window. Most seeds germinate best at about 70 degrees and must be misted or carefully watered regularly.
Transplant seedlings into larger pots as they grow in spring; harden them off by gradually exposing to sunlight outdoors, then plant.
Collect seeds with care: get permission from property owners, take no more than 10 percent of the supply (birds depend on seeds all winter) and don’t harvest rare plant seeds.
If you haven’t grown your own before, it may be easier than you think; give it a try this year.
More information, photos and resources are at GranbyInvasivePlants.Weebly.com