The cover crop seeding rate calculator tells you exactly how many pounds of seed you need for your plot. Select a cover crop species, enter your area, and get the precise seed quantity based on extension service guidelines.
Seed Selection
Seed Quantity
Select a crop and enter your plot area.
Cover Crop Reference Table
| Crop | lbs / 1000 sq ft | Season | Primary Benefit |
|---|
How to Choose and Seed Cover Crops
Cover crops transform idle garden beds into soil-building powerhouses. The right species at the right seeding rate can fix 50-200 lbs of nitrogen per acre, suppress weeds by 60-90%, and add 2-4 tons of organic matter annually.
Matching Crop to Season
Fall cover crops (winter rye, hairy vetch, crimson clover) are planted 4-6 weeks before the first hard freeze and terminated in spring. Summer cover crops (buckwheat, cowpeas, sorghum-sudan) are planted after spring harvests and terminated before fall planting. Buckwheat is fast — it completes its life cycle in 30-45 days, making it ideal for filling short gaps.
Seeding Rate Matters
Under-seeding leaves gaps for weeds to establish. Over-seeding wastes money and creates overly dense stands that are harder to terminate. For broadcast seeding (no equipment), increase the recommended rate by 25% to account for uneven distribution. For small gardens, broadcast by hand and rake into the top 1/2 inch of soil.
Legumes vs. Grasses
Legumes (clover, vetch, field peas) fix atmospheric nitrogen through root nodule bacteria. A stand of hairy vetch can fix 100-150 lbs N per acre. Grasses (rye, oats, wheat) build organic matter, prevent erosion, and suppress weeds, but do not fix nitrogen. The best systems combine both: a fall grass-legume mix like winter rye + hairy vetch at 50% of each species' full rate gives you nitrogen fixation plus erosion protection.
Frequently Asked Questions
Is this cover crop seeding rate calculator free?
Yes, completely free with no signup required. Seeding rates are based on university extension service recommendations for home garden and small farm use.
What is a cover crop?
A cover crop is a plant grown primarily to benefit the soil rather than for harvest. Cover crops prevent erosion, suppress weeds, fix nitrogen (legumes), add organic matter, and break pest cycles between cash crop seasons.
When should I plant winter rye as a cover crop?
Winter rye (cereal rye) is planted in fall, typically 4-6 weeks before the ground freezes. It germinates in cold soil down to 34°F and overwinters to provide ground cover. Terminate it in spring 2-4 weeks before planting your cash crops.
How much does cover crop seed cost?
Prices vary by species: winter rye runs $0.30-0.50/lb, crimson clover $1.50-3/lb, buckwheat $0.80-1.50/lb, and hairy vetch $1-2/lb. For a 1,000 sq ft garden, expect to spend $3-30 depending on species.
Can I mix cover crops?
Yes, mixes are often recommended. A classic fall mix is winter rye + hairy vetch (grass + legume) — the rye provides structure and the vetch fixes nitrogen. Reduce each species' seeding rate by 30-50% when mixing.
How do I terminate a cover crop?
Options include mowing and tilling under (green manure), tarping to smother, crimping with a roller, or using a flame weeder for small plots. For no-till gardens, cut at soil level and leave the mulch in place.