Compost vs Crushed Limestone

Compost

Decomposed organic matter used as a soil amendment to improve soil structure, fertility, and water retention. Quality compost is dark, crumbly, and earthy-smelling. It adds beneficial microorganisms and nutrients that support healthy plant growth and improve poor soils.

Crushed Limestone

Crushed sedimentary rock with a pale gray to white color. Compacts well and provides good drainage. Limestone is a popular choice in the Midwest and South where it's quarried locally, keeping costs low.

Compost

• ✓ Soil amendment
• ✓ Garden beds
• ✓ Lawn top-dressing
• ✓ Raised beds
• ✓ Tree and shrub planting
• ✓ Seed starting mix

Crushed Limestone

• ✓ Driveways
• ✓ Pathways
• ✓ Base material
• ✓ Garden beds
• ✓ Parking pads
• ✓ Erosion control

Compost

• + Dramatically improves soil structure and fertility
• + Increases water retention in sandy soils
• + Improves drainage in clay soils
• + Adds beneficial microorganisms
• + Reduces need for chemical fertilizers

• − Quality and composition vary widely between sources
• − Can be odorous when fresh
• − May contain weed seeds if not fully composted
• − Too rich for direct planting — must be mixed with soil
• − Settles significantly after application

Crushed Limestone

• + Compacts into a firm, stable surface
• + Light color brightens landscapes
• + Good drainage properties
• + Affordable in limestone-rich regions
• + Natural weed suppression when compacted

• − Can become muddy when wet (stone dust)
• − Limited color options
• − May raise soil pH over time
• − Dusty in dry conditions
• − Not available everywhere

Compost

Fine, crumbly texture when fully decomposed. Dark brown to black color. Should smell earthy, not sour or ammonia-like. Screened compost has been filtered to remove large uncomposted pieces. Mushroom compost is a byproduct of mushroom farming and is particularly nutrient-rich.

Crushed Limestone

Available from fine limestone screenings up to 3-inch chunks. Most common sizes are 3/4" and 1.5". Color ranges from pale gray to off-white, sometimes with a slight yellow tint. Compacted limestone screenings create a smooth, almost concrete-like surface.