How to Turn Fall Leaves Into Free Mulch (and How Much You Need)

Shredded fall leaves make free mulch. Penn State Extension suggests a 2- to 4-inch layer of shredded leaves around trees, shrubs and perennial beds, and up to about half an inch mowed into the lawn. Shred them first: shredded leaves mat down less than whole ones.

How much shredded leaf mulch you need

Figures are for a 3 in layer. A 30-gallon yard bag holds about 4 cu ft, so the counts assume bags filled with leaves that are already shredded. For other depths, use the mulch calculator.

50 sq ft — 12.5 cu ft, about 4 bags

100 sq ft — 25 cu ft, about 7 bags

200 sq ft — 50 cu ft, about 13 bags

300 sq ft — 75 cu ft, about 19 bags

500 sq ft — 125 cu ft, about 32 bags

Three ways to use fall leaves

Mow them into the lawn. Use a mulching mower on its highest setting and mow when the leaves are dry. Go over them a second time, or across, for finer pieces. Penn State keeps the layer to about half an inch; Colorado State says it is fine as long as you can still see grass. Colorado State Extension, citing Michigan State researchers, says three years of this can nearly eliminate dandelions and crabgrass.

Mulch your beds. Spread 2 to 4 inches of shredded leaves around trees, shrubs and perennials, then water them in so they stay put (Penn State). Around tender or new plants, Colorado State suggests 3 to 6 inches as insulating mulch.

Compost them. Whole leaves compost well. Colorado State recommends a bin at least 3 × 3 × 3 ft. If you are short on green material, add 1/4 to 1/2 cup of fertilizer without weed killer per 10 to 15 lb of leaves.

Tools that shred leaves (#ad)

WORX TriVac WG509 — blows, vacuums and mulches. The maker lists an 18:1 mulch ratio and up to 350 CFM from a 12 amp corded motor. See it on Amazon

WORX WG430 Leaf Mulcher — a stand-alone shredder that the maker says handles up to 53 gallons of leaves a minute at an 11:1 ratio. It empties into a bag you attach underneath (bag not included). See it on Amazon

A mulching mower you already own works too. As an Amazon Associate, Curb Calc earns from qualifying purchases.

Fall leaf mulch FAQ

Can you use whole leaves as mulch? Shredded is better. Penn State Extension notes that shredded leaves mat down less than whole leaves.

How deep should leaf mulch be? 2 to 4 inches around trees, shrubs and perennial beds, per Penn State Extension.

Can I mow leaves into my lawn? Yes. Use a mulching mower on dry leaves and stop at about half an inch, or while grass still shows.

How many bags of leaves for 100 sq ft? At 3 inches deep, 100 sq ft takes 25 cu ft, about 7 full 30-gallon bags of shredded leaves.

Sources: Penn State Extension, Leaves Are Treasure, Not Trash; Colorado State University Extension, How to Mow, Compost, and Mulch Leaves.