Any good gardener knows that you plant in the spring and harvest in the fall. In fact, much of our culture in Minnesota revolves around this cycle. The garden frenzy begins in spring, as people begin buying seeds and planning their gardens, then reaches a climax around Mother’s Day when nurseries and garden clubs hold sales and people lovingly plant their newly purchased tomatoes, petunias, marigolds, and pumpkins. In September and October, we transition firmly into harvest mode, don flannel shirts and head out to apple orchards and pumpkin patches in mass to ride wagons, sip cider, and pick out the best Jack-o-Lanterns for Halloween.
If you’re starting a pollinator garden or native planting, however, one of the best times to plant is actually in the fall.
While planting in the fall might not seem intuitive, it makes a lot of sense if you think about the way nature works. Walk through a prairie at this time of year and flowers such as black-eyed Susans, blazingstar, and anise hyssop are beautifully in bloom. Likewise, the seed heads have formed on big and little blue stem, Indian grass, and other native grasses. By late October and early November, the seeds from all of these plants will be blowing in the wind and then coming to a rest on the surface of the soil. These seeds remain dormant until the spring, when they germinate and sprout into new flowers, grasses, and sedges.
In the Twin Cities area, early November to mid-December is usually the best time to seed bee lawn and native plants. According to staff at the Minnesota Bee Lab, “It may seem strange, and maybe too good to be true, to just thrown down bee lawn seed on top of the ground without doing any other steps, but that is exactly how it works when you dormant seed.” The key is to avoid planting too early, when seeds might potentially germinate in the fall. Make sure also that the seeds are actually touching the soil, rather than resting on top of leaf litter or existing plant residue. During the winter, the freeze-thaw cycle helps native seeds to stratify and work their way into the soil.
Fall dormant seeding increases germination in most wildflowers and allows for germination very early in the spring before crabgrass and annual weeds have begun to grow. It is an especially good strategy for droughty, sandy soils and wet clay soils. Using this strategy, most full sun prairie plants will grow enough to bloom next summer, while woodland plants may require a few years to grow to maturity.
If you’re interested in having instant gratification, it is also possible to plant native plants from small packs or pots in the early fall between September and mid-October. Planting at this time of year takes advantage of the cooler weather and more frequent rainfall and gives plants a chance to begin rooting before the winter. Weeds are also less of a problem in the fall. Keep the new plants lightly watered until the ground freezes if there isn’t enough rain, but they should not need to be watered in the spring unless it is very dry. Perennials are adapted to survive the winter, so don’t worry about covering them to protect them from the snow.
Most native plants do well with fall plantings, but there are a few milkweed species that are better planted in the spring – butterfly milkweed, poke milkweed, common milkweed, and purple milkweed. Whorled milkweed and swamp milkweed, however, do well in the fall. If you are planting milkweed from seed, all species do well with fall dormant seeding.
To learn more about gardening with native plants, visit BlueThumb.org or sign up for a free site visit with Washington Conservation District at www.mnwcd.org. In addition, Minnesota Board of Water and Soil Resources is currently accepting applications for 2023 Lawns to Legumes grants. Apply between now and January 18, 2023 to receive cost-share funding up to $350 for pollinator-friendly plantings. These grants can be combined with watershed district incentive grants for larger projects. Apply for Lawns to Legumes grants at www.BlueThumb.org.