Six Cover Crops to Sow in September for Spring Soil Health
Gardening Know How recommends six fast-growing cover crops to plant in September, detailing their benefits for soil enrichment, weed suppression, and
Planting a cover crop in September can protect and enrich garden soil over winter. Gardening Know How lists six fast-growing options suitable for sowing this month to build richer soil by spring.
Cover cropping involves growing plants over winter to benefit the soil rather than for harvest. The technique protects bare soil from erosion, adds nutrients, reduces compaction and weeds, and feeds beneficial microbes. September is an ideal sowing time as the soil remains warm enough for germination, giving seedlings time to establish before the first frost.
Winter Rye for Cold Winters
Winter rye is a tough cereal grain that germinates quickly and survives cold conditions. It should regrow in spring, at which point gardeners must chop and work it into the soil promptly. If left too long, its rapid spring growth makes it difficult to kill.
This crop has deep roots that break up compacted soil and reduce erosion. Winter rye is also allelopathic, releasing chemicals that suppress weed seed germination. To sow it, scatter seeds over prepared soil, rake lightly, and keep the area moist.
Oats for Quick Coverage
Oats are a cool-season crop that germinates and grows rapidly in fall. They provide quick soil coverage and a root system that holds soil well. Oats may not survive the winter, depending on climate, but they create a protective mat.
The dead foliage adds nutrients to beds in spring. Oats are easy to work into the soil then, and gardeners need not worry about rapid regrowth in warmer weather.
Crimson Clover for Adding Nitrogen
Crimson clover is a flowering legume that offers soil benefits and an attractive fall cover. It will germinate and establish, potentially surviving winter. In spring, it grows again, blooms, and supports early pollinators before being turned into the soil.
Its primary benefit is nitrogen fixation. As a legume, it converts atmospheric nitrogen into a form that enriches the soil, providing a nutrient boost for next year's plants.
Hairy Vetch, Also for Nitrogen
Hairy vetch is another nitrogen-fixing legume. It is more vigorous than clover, so gardeners should work it back into the soil early in spring before excessive growth.
This plant produces more green material, adding more organic matter to the soil. Its stronger root system makes it particularly useful for addressing erosion or compaction issues.
Field Peas for Nitrogen and Easy Spring Turnover
Field peas are a legume that fixes nitrogen. They are less winter-hardy than other legumes but grow quickly in fall, creating a carpet of vines that covers soil and suppresses weeds even after winter die-back.
A key advantage is ease of spring turnover. Field peas are not difficult to control and incorporate into the soil, even if they haven't fully died over winter.
**Annual Ryegrass for a Quick Root System**
Annual ryegrass develops a dense root system quickly after sowing. This holds soil together, reduces erosion, and improves compacted soil structure.
It may survive winter and grow rapidly in spring. If it does, gardeners must chop and turn it into the soil early to prevent it from taking over beds.
The source notes that regular watering is needed as any cover crop establishes. In spring, each must be turned into the soil, so gardeners should consider the effort required for that task. Mary Ellen Ellis, a gardener with over 20 years of experience, authored the guide.
