As the growing season winds down, it’s common for gardeners to remove dead or dying plants, leaving a clear, empty garden bed for winter. In our “Garden in Fall” workshop a few weeks ago, we learned how there are several benefits to not clearing beds entirely.
First, leaving annual and perennial plants, instead of cutting them back or pulling them out, leaves potential habitat for insects who overwinter in plant debris or lay their eggs. Unless you experienced an infestation in a specific group of plants, it’s great to leave things for clean up in spring instead. At the very least, consider cutting plants off and leaving roots, so as to not disturb soil biology and leaving roots to hold soil in place.
Second, leaving soil exposed creates the potential for erosion and nutrient loss. Soil likes to be tucked in and covered with living or dead plant material as much as possible through the year.
Two ways to keep soil covered and continue to feed soil microorganisms all year is using a mulch or planting cover crop. Cover cropping is a practice more commonly used in agriculture where larger areas of soil can be left exposed and subject to erosion. Cover crops are crops that are direct seeded with the central intention of improving and protecting the soil. They are not harvested except potentially to feed livestock. They can serve a variety of purposes from building soil carbon, increasing nitrogen, deterring soil borne pathogens or weeds, to attracting pollinators. Although most commonly found at larger, agricultural scales of growing, there is no reason a home gardener couldn’t try cover crops in their garden too!
At Green Venture’s EcoHouse, we sowed two different types of cover crops in sections of our veggie gardens finishing up: cereal rye and a mix of peas, oats, and tillage radish. We will be making a few packets of each of these available in our seed library on site this fall.
Cereal rye is an amazing fall cover crop that can continue to germinate and grow in temperatures close to freezing, establishing a fine cover that will take off in early spring. The only trick with this crop is cut or pull it before it gets 6” tall, leaving it for 1-2 weeks before planting other plants into the bed. It’s an excellent cover for overwinter, providing carbon to soil and pushing out weeds.
Peas and oats are easy-going cover crops that can be sown spring through early fall. They will die with frost, but will leave their roots and debris to protect soil over winter. They enhance nitrogen and carbon in soil and are easy to grow. Allow them to grow for at least 6 weeks to get full soil benefits.
Tillage radish can also be added to peas and oats in the fall or grown separately. As the name implies, these radishes send deep tap roots into the soil, aerating and loosening heavy soil, which then rot down over winter so water can penetrate these holes in the soil in spring. They can be a little stinky, but nothing compares for helping compacted soil!
If you’d like to try cover cropping in your garden, swing by the EcoHouse Seed Library to get some seeds. Rye can still be sown this time of year. Peas and oats and radish will also be available, but it’s recommended you save the seed for spring.
If sowing at home, clear beds of weeds and debris (you can sow under plants, just make sure the seeds can make contact with soil). Spread seed out over soil. Rake in. Water in if there is no rain in the immediate forecast and keep moist for 3-5 days or however long until germination.