Square Foot Garden Soil Mix: Fixing Sand Substitution Failure

Why Sand Failed

Sand + peat + manure without vermiculite = poor structure. Sand compacts, reducing aeration. 15-15-15 fertilizer then burned roots in the dense, poorly draining mix.

Recommended Mix (Mel's Mix Alternative)

• 1/3 compost (diverse sources).
• 1/3 peat moss or coconut coir.
• 1/3 coarse vermiculite (not sand).

If vermiculite cost-prohibitive: substitute perlite (cheaper, similar aeration) or rice hulls (renewable).

Simpler Approach

• 60% topsoil, 30% compost/manure, 10% sand/perlite.
• Mulch with straw (not peat) for moisture retention.
• Change one variable at a time to diagnose.

Fertilizer Caution

Organic mixes need little added fertilizer. Compost feeds slowly. Synthetic 15-15-15 is too strong for small volumes.