Using Wood Chips: Mulch Benefits, Aging, and Nitrogen Management

Wood chips are inexpensive mulch and ground cover. Tree companies often dump chip trucks in homeowners' yards—no disposal fee for them, free mulch for you.

Jim Foote at Arborguard Tree Specialists notes chips often mix with pine straw and leaves—not always pure wood chips. Trucks are large; ensure space for 5–10 cubic yards.

Spreading a thin layer (1–2 inches) under shrubs/trees poses no threat. Thicker layers could theoretically harm from water-soluble sap materials washed out by rain. Safe rule: wait until pile has had several rains/waterings to dissolve harmful chemicals before landscape use.

Q: Can I use wood chips as mulch around vegetables?

A: Yes, if chips aren't from walnut trees and have no contaminants. Fresh chips should age and be rained on a few times first. Keep layer thin—1 inch or less. Keep chips 3 inches from vegetable stems. Use between garden rows; they'll decompose over summer and can be tilled in fall.

Q: What about chips from stump grinding?

A: Rake up most chips and use as mulch under landscape shrubs. No need to be obsessive. Fine for flowers/vegetables too. Could dig into garden soil if you add extra fertilizer to feed fungi breaking down chips. Without added nitrogen, plants won't get all nutrients.

How much extra fertilizer? Increase normal application by ~25%. Or mix 6 pints of 10-10-10 fertilizer with chips and soil per 1,000 sq ft.