Mulching Guidelines

Got mulch? You can use less water and improve the health of your trees and plants by using a layer of mulch, three to four inches deep, around your trees. Instead of having your “yard waste” hauled away, you can mulch by simply allowing fallen leaves and other plant matter to stay on the ground.

Here's how to mulch:

1. Make or obtain mulch

To make your own: When you prune trees, you can chip the non-diseased branches into mulch using a chipper or your own pruning tools. Chippers will work on branches up to 3 inches in diameter. You can purchase or rent one from home improvement stores or equipment rental businesses.

Do not use grass clippings as mulch around plants. They smother the soil and do not allow oxygen to get into the soil. Compost your grass clippings instead.

Under existing trees and shrubs, allow the leaves and branches to fall and stay on the soil. Do not rake them up and throw them away, unless they are diseased.

2. Remove weeds

Remove weeds from around the base of the tree before mulching.

3. Break up the soil

If the soil surface is highly compacted, break up the surface using a metal rake or shovel before mulching.

4. Place the mulch

Place a 3- to 4-inch layer of mulch around the tree. Keep the mulch at least 2 inches away from the base of the tree. If possible, mulch all the way out to the dripline (the dripline is the area that reaches out from the trunk and extends to the end of the branches). Be sure to mulch over the berm if you've created one around your tree.

Additional mulching tips & resources

  • Tree pruning and landscape maintenance companies are another good source for mulch. Some companies will deliver for free to avoid a disposal fee at the landfill.
  • Mulch by the cubic yard can be purchased from tree and soil farms such as American Soil Amendment Products and Nursery in Simi Valley, B.D. White Topsoil, Inc in Torrance (310) 370-5511 or Home Depot and other large home and garden stores.
  • Free mulch is available in six locations across Los Angeles from the City of Los Angeles Bureau of Sanitation Mulch Program, but this is really composted yard waste from the city's yard waste collection.  It tends to be dense and is better used as an amendment added and dug into problem soils (compacted heavy clay or extremely sandy soil) rather than mulch to cover the soil.
  • Do not buy sawdust or wood shavings for mulch. These won’t allow enough air into the soil.
  • Wood or bark chips work best when they are between one and three inches in size. Pieces smaller than that can smother the soil and do not allow enough oxygen to get into the soil. Larger pieces get kicked around or can cause tripping.