Covering a French Drain in a Clay Yard

After installing a French drain in clay, the trench backfill must drain quickly but match the surrounding soil long-term.

Backfill Options

• Pea gravel or coarse sand: drains fast, but thin layer only.
• Better: Blend native clay with compost and coarse sand, then topdress with quality topsoil.
• Avoid sharp texture contrasts (sand over clay = perched water).

Ideal Sequence

1. Add topsoil/compost blend over entire yard.
2. Till to blend with clay.
3. Re-grade; the drain becomes part of a uniform profile.

Layered soils cause more problems than they solve. Integrate the drain into a rebuilt soil profile.