How to Grow Cover Crops
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Cover Crops
Fagopyrum esculentum (Buckwheat) / Trifolium spp. (Clover)
grassCover crops are non-commercial plants grown primarily to improve soil health, prevent erosion, and suppress weeds rather than for harvest. Common types include buckwheat, clovers, rye, and legumes, which add organic matter, fix nitrogen, and enhance soil structure. They are typically planted in off-season or fallow areas and turned into the soil as green manure.
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Example Cover Crops timeline · Pittsburgh, PA (Zone 6b)
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Plant Cover Crops
Around Apr 17Near Pittsburgh's average last spring frost.
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Tend & protect
Late spring–summerWatering, feeding, and pest-watch reminders.
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Harvest Cover Crops
Around Jun 6≈ 50 days after planting
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Growing Conditions
Soil
Growing Zones
Find your zone →Most cover crops thrive in zones 1-10; specific varieties have different optimal zones. Buckwheat prefers zones 3-9; winter clovers excel in zones 4-9; winter rye in zones 2-10
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Get my Cover Crops timeline →Growth Stages
Germination & Establishment
2-3 weeksSeeds sprout and seedlings emerge with first true leaves visible. Plant appears thin and fragile
Keep soil consistently moist (not waterlogged) for 2-3 weeks. Avoid foot traffic. Light rolling can improve soil contact
Vegetative Growth
4-8 weeksRapid leaf and stem development; plants fill in and create dense canopy. Plant height increases noticeably
Minimal intervention needed. Monitor for pest outbreaks. No fertilizer needed for legumes (they self-fertilize). Water during dry spells
Flowering (optional)
2-4 weeksFlowers appear (white, pink, purple, or yellow depending on species). This stage adds aesthetic value and attracts pollinators
Allow flowering if desired for pollinator support and maximum nutrient accumulation. Time incorporation before seed dispersal to prevent volunteers
Biomass Maturation
2-4 weeksPlants reach maximum dry matter and nutrient content. Stems thicken; leaves may begin yellowing in late-season crops
Plan incorporation timing. For spring crops, allow 2-4 weeks before turning in soil to allow decomposition
Incorporation/Termination
VariableCover crop is killed and worked into soil, becoming green manure that improves soil structure and adds organic matter
Cut, mow, or plow into top 4-6 inches of soil. Allow 2-4 weeks before planting vegetables to permit decomposition. Winter-killed crops naturally die back
Companion Planting
Plan your garden →Plant with:
Avoid planting near:
Common Pests
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Typically minor issue in cover crops. Encourage natural predators. If severe, use spinosad or allow parasitic wasps to control
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More problematic in brassica cover crops. Use row covers during establishment or spinosad if population is high
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Larvae feed on legume roots but rarely cause economic damage in cover crops. Plow under promptly in spring to disrupt lifecycle
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Minor feeding on foliage; typically not concerning. Hand-pick if severe or allow cover crop to be sacrificed
Uses
Soil Improvement & Green Manure
HouseholdCover crops dramatically improve soil structure, organic matter content, and water-holding capacity when incorporated. Legume-based covers (clover, vetch) fix atmospheric nitrogen into forms available to subsequent crops, reducing or eliminating the need for synthetic fertilizer. [source]
Erosion Prevention & Weed Suppression
HouseholdDense foliage prevents soil erosion from wind and water, stabilizing hillsides and preventing runoff. Allelopathic compounds and physical shading suppress weed germination and growth, reducing hand-weeding labor. [source]
Pollinator & Beneficial Insect Support
WildlifeFlowering cover crops (especially clovers and buckwheat) provide abundant nectar and pollen for bees, butterflies, and other pollinators during off-season when few food sources are available. They also attract parasitic wasps and other predatory insects that control garden pests. [source]
Pest & Disease Management
HouseholdCover crops can suppress soil-borne pathogens (especially brassica covers against clubroot) and reduce pest populations through crop rotation and habitat disruption. Winter covers eliminate bare ground where pests overwinter. [source]
Human & Livestock Forage (select species)
CulinaryBuckwheat produces edible grain and nutritious forage; clover is nutritious livestock feed. Some cover crops can be partially harvested as food or animal feed before soil incorporation (e.g., crimped buckwheat or clover hay). [source]
Harvest Tips
Cover crops are not typically harvested for consumption. Instead, they are terminated and incorporated: (1) Buckwheat: Cut or mow when flowers appear (50-70 days), work into soil immediately or let dry 1-2 weeks. (2) Legume clovers: Mow or plow under when flowering to early pod stage (60-90 days) to maximize nitrogen fixation. (3) Winter crops (rye, winter wheat): Allow natural winter kill or plow under in early spring before growth resumes. (4) For maximum nutrient capture, incorporate when biomass is lush but before heavy seed set. Allow 2-4 weeks decomposition before planting vegetables
Fun Facts
- 🌱 Buckwheat flowers attract bees so effectively that it is sometimes called 'liquid gold' for beekeepers—a single acre can produce over 100 pounds of honey.
- 🌱 Nitrogen-fixing legumes like clover contain nodules on their roots that harbor beneficial bacteria (Rhizobium) capable of converting atmospheric nitrogen into plant-available forms, effectively creating free fertilizer worth $50-150 per acre.
- 🌱 Winter rye grows even when temperatures drop below freezing, making it one of the most cold-hardy cover crops and ideal for preventing erosion throughout the dormant season in northern climates.
Gardening Terms
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