Eco-friendly ways to use even the toughest leaves in your garden

Leaves are the ultimate ecological garden fertilizer and mulch.

Credit: courtesy Carolyn Herriot

Stockpile leaves in circular wire cages for year-round use.

Leaves are the ultimate ecological garden fertilizer

Leaves are a passionate topic for me—such an incredible garden resource that simply floats down from above, free and available to us all. There is no need to pack them up in plastic bags for municipal pickup, as there are so many wonderful ways to use them in your own yard. Leaves are the ultimate ecological garden fertilizer and mulch.

Recently we received this excellent question from one of our readers, Karlhans Diersch:

Our community has blessed us with pin oaks, which have leaves that do not compost. What do we do with them? And we have lots… during fall, winter and early spring.

This is a great question, and the simple answer is to leave those leaves in your garden.

The stately and long-living pin oak (Quercus palustris, zone 4)—so named because of the small dead branches that characteristically stick out like pins on the main trunk—will produce bales of beautiful leaves. Like beech, birch, hornbeam, magnolia and holly, oak leaves are high in lignin and low in nitrogen and calcium, making them tough in texture and slow to break down. Nonetheless, they remain an extremely valuable resource for the garden.

In the compost, you can hasten their decomposition by adding nitrogen-rich grass clippings. Plus, shredding them with a chipper/shredder, running over them with a lawn mower, or chopping them up by stuffing them into a garbage can (about one-third full) and going at them with a weed whacker will also go a long way to helping them break down, as well as giving them a tidy appearance when used as mulch. Chopped or not, however, oak leaves are extremely useful.

Four ways to use oak leaves

1. As mulch for your garden or container plants.

2. Added to your garden as a repellent to cutworm or leaf-chomping insects.

3. In a lasagna garden.

4. As compost. You can add oak leaves to your compost bin or simply bundle them up to break down, as Carolyn Herriot explains in this excerpt from her bestselling new book, The Zero-Mile Diet: A Year-Round Guide to Growing Organic Food:

Tree roots penetrate widely through topsoil and deeply into subsoil, taking up valuable nutrients, which are then stored in the leaves. When leaves break down they return these nutrients to the soil.

In fall, heap leaves of big trees, such as maples, oak and chestnut in a corner and forget about them. By spring the pile will have broken down into coarse leaf mulch, which can be used as garden mulch. After a full year, the pile will have broken down into beautiful black leaf mulch that can be used in potting mixes, and is perfect for enriching the garden. Take full advantage in fall by stockpiling leaves.

TIP: Run a lawnmower over a pile of leaves on the driveway. This reduces their bulk to a manageable pile of shredded leaves, which can then be spread over beds as mulch without being unsightly.