Time to Think About Fall Sowing a Pollinator Garden

Fall is the perfect time to sow a native-plant based pollinator garden. Native plants not only provide pollen and nectar for pollinators, they also provide habitat and food for egg laying and feeding caterpillars. Pollinators emerge and become active at different times of the year and over time have learned to depend on the plants native to their region. For example Monarch butterflies lay their eggs on milkweed plants and by the time the eggs hatch, the plants are large and leafy providing a buffet for the hungry caterpillars. We offer seed of many plants native to North America and the seed of our Ontario natives was originally collected from locations throughout Ontario and grown out on our farm in Palmerston.

                  Swamp Milkweed

Did you know that many flowering plants and grasses native to northern regions like ours have special germination requirements? This is because by the time the seed matures and falls to the ground winter is often just around the corner. If the seed germinated, odds are it would not survive. Clever things that they are, many northern plants have built in germination inhibitors in their seed. The cold and damp of winter degrade these germination inhibitors allowing the seed germinate when conditions are right for growth. We call this process cold, moist stratification.

You can replicate this process by chilling your seed in a damp paper towel in a sandwich bag in your fridge for a specific number of days then sowing the chilled seed in the spring. See the plant list below for chilling requirements.  Alternatively (and my favorite method) you can sow the seed in late fall and allow mother nature to do the damp chilling work for you. If you choose mother nature, prepare a weed free spot in your garden and once frost is imminent, direct sow seed according to package directions. Another option is to sow seed into containers in late fall and keep the pots outdoors to experience winter conditions. The seedlings will emerge in spring and can be allow to grow in the pots and then planted in the garden in spring or summer.

Different species require  different periods of chilling. CM(30) indicates a plant that requires 30 days of cold moist stratification to germinate.  If you cold moist stratify in the fridge, use these numbers to time when to put the seed into the fridge. If you fall sow, the required number of days will be met by winter conditions and the seed will germinate in spring.

I like to sow a mixture of flowers and grasses in my pollinator patches. Some of my favorite species for fall planting are:

Butterfly Milkweed, Asclepias tuberosa CM(30)
Swamp Milkweed, Asclepias incarnata CM(30) (shown above)
Wild Bergamot, Monarda fistulosa – no treatment necessary but does well with fall sowing
Ironweed, Vernonia missourica CM(60)
Black-eyed Susan, Rudbeckia hirta CM(30)
Grey Headed Coneflower, Ratibida pinnata CM(30)
Great Blue Lobelia, Lobelia siphilitica CM(60)
Blue Vervain, Verbena hastata CM(30)
Wild Columbine, Aquilegia Canadensis CM(60
Smooth Beardtongue, Penstemon digitalis
Tall Coreopsis, Coreopsis tripteris, CM(60)
Lance-leaf Coreopsis, Coreopsis lanceolata CM(30)
Anise Hyssop, Agastache foeniculum CM(30)
Purple Coneflower, Echinacea purpurea - no treatment necessary but does well with fall sowing
Narrowleaf Coneflower, Echinacea angustifolia CM(90)


                Big Bluestem Grass


Little Bluestem, Schizachyrium scoparium - no treatment necessary but does well with fall sowing
Big Bluestem, Andropogon gerardii - no treatment necessary but does well with fall sowing
Indian Grass, Sorghastrum nutans - no treatment necessary but does well with fall sowing