Nadie VanZandt, University of Vermont Extension
Before taking a rest from gardening for the season, have you thought of direct sowing seeds to grow a minimal-care garden next spring?
Like spring bulbs, many seeds require a natural freezing and thawing before awakening in the spring. Seeds from several annuals, biennials and perennial plants are good candidates for fall planting.
With just a little extra work, direct sowing in the fall is a simple and inexpensive way to grow a colorful garden with plants that will bloom earlier than when seeded in the spring.
Your first step is to select the right plants for your region and your U.S. Department of Agriculture (USDA) plant hardiness zone. Just enter your zip code at planthardiness.ars.usda.gov to find your zone. To ensure the plants you choose are not listed as invasives in your area, please visit vtinvasives.org.
Generally, seeds that require cold stratification are well suited for fall seeding in USDA hardiness zones 3-5, which are the zones in Vermont. You may have already noticed “volunteers” in your garden from plants that dropped their seeds last autumn, proof that these seeds survived the long New England winter.
Self-seeding perennials that benefit from cold winters include poppy (Papaver), bee balm (Monarda), black-eyed Susan (Rudbeckia hirta), columbine (Aquilegia), coneflower (Echinacea), delphinium, milkweed/butterfly plant (Asclepias) and lady’s mantle (Alchemilla), among others.
Similarly, seeds of biennials like foxglove (Digitalis), sweet William (Dianthus) and hollyhocks (Alcea rosea) are also good choices for direct sowing in the fall.
Don’t overlook the seeds of many annuals known to self-seed. These include annual poppies like breadseed poppy (Papaver somniferum), larkspur (Delphinium consolida), love-in-a-mist (Nigella), nasturtium (Tropaeolum), pansy (Viola), calendula and cosmos, as well as seeds from hardy annuals.
In your vegetable patch, you also can try seeds of cold hardy vegetables such as beets, kale, lettuce, spinach, carrots, leeks and others that can withstand frost. Herbs, including dill, will do well when seeded in the fall.
You will need to prepare your planting bed the same way you would in the spring. Select a sunny and well-drained area and remove any weeds and debris. Lightly loosen the surface of the soil, taking care to not disturb the soil organisms and avoid releasing weed seeds to the surface. Amend the soil with a thin layer of compost.
Some seeds require light to germinate while others need darkness, so it’s important to follow the instructions on your seed packets. You may or may not need a layer of mulch depending on the specific light requirement.
The seeds need to experience the correct sequence of winter cold followed by spring thaw. It’s a good idea to plant them after a killing frost to make sure that they do not have a chance to germinate until the time is right in the spring.
Direct sowing at this time of year has many other advantages. Come springtime, you won’t need to harden off your seedlings, and they won’t need to recover from the stress of transplanting. By overwintering in the garden, your seeds will produce stronger, healthier and well-acclimated seedlings.
Consider direct sowing this fall before taking a well-deserved rest this winter. You will appreciate your foresight when gazing at your healthy seedlings next spring.
(Nadie VanZandt is a University of Vermont Extension master gardener from Panton.)