New Mulch Over Old Mulch

The benefit of mulch over a flowerbed or lawn is to provide nutrients and reduce soil compaction to conserve moisture and assist in maintaining soil aeration during rainfall. It also helps to limit soil erosion and water runoff, stabilize soil temperature and promote the development of microorganisms and worms. All of this is possible because over time mulch decomposes and releases nutrients and organic matter.

Since mulch decomposes, it is necessary to periodically replace or cover it. The mulch should be renewed occasionally to a layer of 2-inches to 4-inches deep on the soil surface.

Items You Need To Restore Mulch

What you will need to cover old mulch with new is:

  • Any type of mulch material including pine needles or bark; composted wood chips, straw, leaves or twigs.
Leaves for mulch.
Image by JamesDeMers from Pixabay

Preparing New Mulch

Application of mulch should occur in spring when the soil has had time to recover from winter temperatures. Adding mulch too soon can delay soil warming and slow plant growth.

Don’t use leaves from diseased plants to be part of the new mulch. You also need to take care not to disturb the old mulch when adding a new layer. This is because the old mulch may have fungal diseases that could penetrate into the soil or threaten your plants if the old mulch is disturbed.

Shredding grass clipping or leaves are ideal materials to use for new mulch. Shredding the clippings and leaves are important because if left whole, they can mat and prevent water from reaching the soil.

North Carolina State University agriculture department suggest that you not use yard waste that has been in a pile for weeks as material for mulch. The refuge will become highly acidic due to anaerobic decomposition and can harm or even kill plants. If anaerobic decomposition is occurring, you will smell vinegar, ammonia, or sulfur coming from the refuge pile.

Applying Mulch

Collect enough mulch material to cover the entire area you want to mulch. According to North Carolina State University, 9-cubic feet of mulch will create a depth of 1-inch.

In order for the mulch to be most beneficial without adversely affecting the plants, make certain that the mulch does not come too close to plant stems or cover plants. Measure an area of about 1-inch to 2-inches from the plant stem and clear it of any old mulch.

Cover the old mulch with the new mulch starting at the edge of the cleared zone around the base of the plants and work outward. A new layer of about 1-inch should be sufficient.


About Robert Janis

Written by Robert Janis for LawnEq - Your specialists for Lawn Mower Parts and Small Engine Parts. We offer genuine premium OEM parts for Land Pride, Toro and many more dependable manufacturers.