A living mulch is a low plant such as white clover grown over the soil to shade it, suppress weeds and, if it is a legume, add nitrogen. It also uses water through its leaves, so in a dry climate it suits the spaces under established trees and perennials better than the rows of young annual crops. Mow or cut it to control its height and compete less, and keep a bare or mulched circle around new plants.
A living mulch is a plant cover grown on the soil surface between or under crops to do the jobs of mulch, with the added effects of roots, nitrogen fixation and a continuous water draw.
A Living Cover Saves Soil Water By Shading And Spends It By Transpiring
A dead mulch only shades and insulates. A living one does that and also takes up water and transpires it. Whether a living mulch leaves more or less water for the crop than bare soil depends on the climate, the species, how often it is cut and whether the crop’s roots reach below the cover’s. In a dry-farmed field a competing cover can take what the crop needs. Under established trees, whose roots go deeper, the cover’s cost is lower and its benefits (weed suppression, soil protection, nitrogen) are real.
The carrier guide (Drought Resilience & Water-Efficient Agriculture) lists living mulch (clover) in its mulch table as a perennial that also fixes nitrogen. For food forest uses, see Ground Cover and Root Crops.
What You Need
- Low-growing species matched to climate and shade: white clover, creeping thyme, strawberry, other short perennials.
- Seed or plants.
- A mower, scythe or shears to cut the cover.
- Water to establish it.
Method
Step 1: Choose by job. Legume covers for nitrogen (Nitrogen Fixation); herb and flowering covers for pollinators; any low cover for soil protection.
Step 2: Establish with water, and keep weeds out while it fills in. A cover that has not closed is not yet a mulch.
Step 3: Keep it away from young trees and crops. Leave a bare or mulched circle at each trunk and along each row, as the carrier advises for the food forest.
Step 4: Cut regularly, leaving the clippings on the surface as a dead mulch. Cutting returns the nitrogen in the top growth to the surface.
Step 5: Watch for competition. If the crop wilts in dry weather while the cover stays green, cut harder, widen the clear strip, or remove the cover.
Common Mistakes
- Sowing a living mulch under a dry-farmed annual crop — it competes for the same stored water.
- Allowing grass to take over — it competes strongly with young fruit trees.
- Never cutting — tall cover shades and robs the crop.
What’s Next
- Learn next: Soil Organic Matter and Water Holding Capacity — what covers add over time
- Combine with: Cover Crops — covers for fallow ground