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Holly's Homestead — Soil & Compost

Green Manures & Cover Crops

Grow a crop specifically to feed the soil, not to harvest
DIFFICULTY Easy
TYPE Seasonal technique
TIME 6–12 weeks per cycle
Difficulty
Easy
Time
6–12 weeks
Cost
Low
Best Season
Between main crops, or over winter
Frequency
1–2 times a year per bed

01Grown to be dug back in

A cover crop like clover, mustard, or field peas is sown into an empty bed, then cut and dug in (or left as mulch) before it seeds — adding organic matter and, for legumes, fixed nitrogen back into the soil.

02What you'll need

  • Cover crop seed suited to your climate and goal (e.g. clover, mustard, field peas, oats)
  • An empty bed between main crops
  • A mower, slasher, or secateurs for cutting back before digging in

03Method

  • 1. Choose a cover crop suited to the season and your goal — legumes for nitrogen, brassicas like mustard for pest/disease break, grains for biomass.
  • 2. Sow densely across the bare bed.
  • 3. Let it grow until just before flowering, when nutrient content peaks and it hasn't yet set seed.
  • 4. Cut it down and either dig it into the top layer of soil, or leave it as a mulch (no-dig approach).
  • 5. Wait 2–3 weeks after digging in before planting the next crop, to let initial breakdown occur.

04Troubleshooting

  • Cover crop sets seed and becomes a weed — cut it back before flowering finishes; don't leave it too long.
  • Poor germination — often from a dry surface; water in well after sowing.
  • Slow breakdown after digging in — very woody or mature growth breaks down slowly; cut earlier and smaller next time.
  • Not enough time between main crops — choose a fast-cycling cover crop, or skip a full cycle and use mulch instead.

05Timing & maintenance

Best time
Any gap between main crops, or over an entire winter/off-season on a bed that would otherwise sit bare.
Duration
6–12 weeks depending on the cover crop chosen and the season.
Maintenance
Minimal once established; mainly timing the cut-back correctly.
Signs of success
Vigorous, dense green growth about to flower, ready to be cut and incorporated.

06Tips & variations

Pairs well with
Building Healthy SoilNo-Dig Gardening
Common mistakes
Letting the cover crop set seed before cutting it backLeaving a bed bare instead of cover-cropping it over an off-season
Pro tip
Field peas or another legume cover crop is one of the most effective ways to build nitrogen ahead of a hungry crop like corn or brassicas.