Turn your fallen leaves into leaf mold

Leaf mold's name might account for why it's not more popular among gardeners. While it sounds like a disease that might affect your trees, leaf mold is actually a beneficial soil amendment that can easily be created using only the leaves that litter your lawn in the autumn.

You can create this material simply by allowing leaves to partially decompose over time. Kathy LaLiberte, writing for the Gardener's Supply Company, says this process creates a crumbly material with a pleasant scent.

While fallen leaves can be a crucial component in compost, which helps improve soil fertility, leaf mold is a separate material with its own distinct benefits. Colleen Vanderlinden, writing for the home design site The Spruce, says leaf mold will greatly improve the soil's water retention and provide a good habitat for helpful bacteria and earthworms.

Leaf mold can be tilled into the soil, or spread on top of the soil to act as a mulch. The Royal Horticultural Society says the material is also useful as a top dressing for lawns during the autumn and for covering bare soil in the winter.

Consider the type of leaves on your property when creating leaf mold. Certain trees, like oak and beech, produce leaves that break down easily. Others, like sycamore and walnut trees, have thick leaves that should be shredded first.

Conifer needles will break down too slowly to be useful in a leaf mold pile. However, pine needles can be collected separately to make a leaf mold which will benefit plants that prefer more acidic soils, such as blueberries and rhododendron. Autumn Hill Nursery & Landscaping, a company in Woodstock, Ga., says black walnut leaves should not be included since they have a natural herbicide which inhibits seed germination.

Shredding leaves will help accelerate the formation of leaf mold. Vanderlinden says it will typically take about six to 12 months for the leaves to decompose effectively. LaLiberte says it may take two or three years for leaf mold to be ready, particularly if the leaves are dry.

The easiest way to start making leaf mold is to rake a pile of leaves into an unused part of your yard. Vanderlinden says a pile should be at least three feet square. LaLiberte says a pile measuring about six feet square and five feet tall is ideal, though four or five feet square also works well.

Natural piles are more likely to be disrupted by wind or other factors, so you might want to collect the leaves in a wood or wire enclosure. Autumn Hill Nursery & Landscaping says these enclosures should be covered to keep leaves from blowing out.

You can also allow leaves to decompose in bags. Marie Iannotti, also writing for The Spruce, says tall paper leaf collection bags are one option, though they will likely start to rot by the time spring rolls around. Plastic garbage bags will also work, but need to have slits cut into them to provide ventilation.

Minimal maintenance is needed to help with the formation of leaf mold. Laliberte says the leaves should be moistened as needed to keep them from drying out. You can also periodically add fresh leaves, which will provide nitrogen and help speed up the decomposition.

In the spring, leaf mold can be added to a garden in a manner similar to compost. Iannotti says you might add a layer of two to four inches on top of the soil or till the material into the top six inches of the soil.

Leaf mold may create some problems in the garden, so be careful when using it. Since it retains moisture so well, it can promote rot if placed too close to the stem of a plant. The Royal Horticultural Society says leaf mold piles may also become infested with weeds.