#89 Stone vs Compost: Size, Cost, and Which to Use

#89 Stone

In the ASTM C33 sieve table, #8 stone passes a 1/2-inch screen and stays on a #8 sieve (about 3/32 inch), and #9 is a step finer. #89 is a blend of the two: most of it passes a 3/8-inch screen and stays on a #16 sieve. In practice you get a clean, small, sharp stone that looks like crushed pea gravel. Some quarries sell the same product as #8, #9, or "3/8 clean."

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.

#89 Stone

• ✓ Walkways
• ✓ Patios
• ✓ Pipe bedding
• ✓ Asphalt mix
• ✓ Dog runs
• ✓ Driveway top dressing

Compost

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

#89 Stone

• + Packs firmer than pea gravel at the same size
• + Stays put inside edging
• + Wheelbarrow and stroller friendly
• + Clean, so it drains
• + Cheap at $22 to $40 per ton

• − Plain gray look
• − Sharp edges, not for bare feet
• − Too small for a driveway surface
• − Less void space than #57 for drainage

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

#89 Stone

#89 stone is crushed stone screened to about 3/8 inch and smaller, with most pieces between 1/8 and 3/8 inch and no dust. It is angular, a blend of the #8 and #9 sieve sizes. Color follows the quarry: gray or white limestone, gray to pink granite, or dark basalt.

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.