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Leaf Mold

What is leaf mold, and why would my garden need it?

Question: What is leaf mold, and why would my garden need it?


Answer: Leaf mold is the residue of fallen leaves, after they've been broken down by weather, water and microorganisms. It is a soft, crumbly, brown material that takes about a year to form in nature. You can speed up the process by sealing leaves—dampened well first—in black plastic bags. Small leaves can go in whole; larger leaves should be chopped or shredded first. Poke holes in the bags to provide some air circulation. Set the bags aside and within about six months the leaves will turn to leaf mold.

Leaf mold can be spread on the garden like a mulch. It serves to suppress weeds (if piled three inches thick) and it improves the soil structure as it breaks down further. Leaf mold also supports the beneficial soil organisms that keep soil healthy.

Instead of making leaf mold in bags, you can also chop the leaves and spread them on the garden in the fall. Contact with the soil will help them break down. The bag method, however, is advantageous in areas where high winds might blow the chopped leaves away, or in fire-prone areas where spreading dry leaves on the ground would be risky and/or banned by law.

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Find more natural ways to improve your soil with Let It Rot! The Gardener's Guide to Composting.

Find more ideas for reusing plant parts in Don't Throw It, Grow It!

Spread mulch evenly with Clarington Forge's Garden Rake.