Will Oak Leaves Hurt a Newly Seeded Lawn?

Use of Oak Leaves

• The recommended way to use oak leaves on a newly seeded lawns is to shred the leaves prior to application. Applying leaves without shredding prevents sunlight from getting to the seeds. Layers of whole leaves are also more prone to compaction and matting. This is more harmful than helpful not only for new lawns but when used as mulch in any landscape area. Putting any types of leaves on grass, including oak leaves, is not harmful if done properly, according to the Michigan State University Extension.

Preparing Mulch

• To shred oak leaves into a mulch form, spread a thin layer of leaves on the existing grass and mow over the layer. Keep the mower at the height at which the grass is regularly mowed. Work with a rotary mower as this pulverizes the leaves well. Make sure the oak leaves are dry at the time of shredding. Run the mower three to four times over the leaves to attain the right mulch consistency. Finer leaf particles settle better around seeds, allow new grass to grow around them and do not block light or water.

Application Method

• Spread shredded leaves in a thin layer over newly seeded areas. Use enough to have the soil slightly visible through the layer of leaves; applying a very thick layer will stunt seedlings' normal germination and growth. The main purpose of the mulch is to protect seeds from birds, keep them from blowing away and conserve soil moisture for effective germination. Organic mulches like oak leaves will gradually break down and continually add nutrients to the soil. After you have started to mow the grass, leave a thin layer of grass clippings on the lawn as replenishment mulch.

Oak Leaf Alternatives

• Other mulches are easier to use than shredding and applying oak leaves on newly seeded lawns. Straw is the most popular among these, as recommended by David R. Mellor in "The Lawn Bible." Although peat moss is also used as mulch, it has a slower decomposition rate than straw and is likely to compete with grass seedlings for water.