A condition where soil particles are pressed tightly together, reducing pore space, restricting root penetration, and reducing water and air movement through soil.
In plain terms
Compacted soil is hard, dense, and resistant to root penetration. It happens from repeated walking, vehicle traffic, heavy equipment, or poor tillage practices. Roots can't penetrate, water pools on surface or drains poorly, and air space decreases (worse for aerobic organisms). Fixing requires aeration (mechanical or compost + time) or raised beds.
Why this matters
Compacted soil is the silent killer of gardens. Many gardeners blame water or nutrients when compaction is the real problem.
In practice
Examples
High-traffic path: soil compacted, nothing grows; aerate and add compost to restore.
Heavy clay without organic matter: compacts easily with rainfall; annual compost prevents compaction.
Vegetable bed with deep compost layer: loose, no compaction; roots penetrate easily.
Tilled soil when wet: compacted by machinery; causes hardpan; avoid this mistake.
Practical applications
Avoid walking on beds; use pathways; keeps soil loose.
Aerate compacted areas with broadfork or mechanical aerator.
Add compost; improves structure and resists recompaction.