Mycorrhizae in Sandy Soil: Do You Need to Buy Inoculant?

Compost & Manure Likely Provide Enough

Mycorrhizal fungi occur naturally in most soils, especially those enriched with organic matter. Your homemade compost and added manure probably already contain diverse mycorrhizae.

When Inoculant Helps

• Sterile potting mixes / new construction fill.
• Heavily fumigated or chemically damaged soils.
• Specific plant-fungus pairs (e.g., orchids, some conifers).

Better Investment for Sandy Soil

• Composted manure (cow/horse) – Adds fungi + nutrients + water-holding capacity.
• Leaf mold & grass clippings – Feed soil life, improve structure.
• Cover crops (clover, rye) – Host mycorrhizae year-round.

Save money: build soil biology with organic amendments, not packets.