Compost: Complete Guide
Decomposed organic matter that builds soil health from the ground up. Compost improves clay drainage, helps sand hold moisture, and feeds the microbial ecosystem that makes existing soil nutrients plant-available. The NPK is low (roughly 1-1-1) but compost delivers a broad spectrum of micronutrients, humic acids, and beneficial fungi that no synthetic fertilizer provides. Apply 1-3 inches annually as topdressing or tilled into new beds. Unlike chemical fertilizers, compost is nearly impossible to overapply.
Key Facts
What is Compost Best For?
When Should You Use Compost?
Use as a soil amendment before planting new beds, as annual topdressing for established gardens, or to rehabilitate compacted or depleted soil. Work 2-3 inches into the top 6 inches for new beds. Topdress lawns with a quarter-inch layer in fall. Add to potting mixes at 20-30% by volume.
When Should You NOT Use Compost?
Not a quick fix for nutrient deficiencies. Nitrogen release is too slow for heavy feeders like corn or tomatoes at peak growth. Fresh (unfinished) compost robs nitrogen from soil as it continues decomposing, so only use fully cured compost that smells earthy and crumbles easily.