How to properly mulch around landscape trees

bark mulch

Mulching can improve soil structure and fertility by mimicking the natural environment in forests and replenishing nutrients needed for root growth. However, improper application can negatively affect tree growth over time. Learn how to choose the right mulch and how to apply it around landscape trees for optimum growth.

Benefits of mulching

There are many benefits to mulching around landscape trees. They include:

  • Conserving soil moisture
  • Improving soil structure
  • Moderating soil temperature
  • Reducing damage to trees from mowers and trimmers
  • Reducing foot traffic and subsequent soil damage
  • Reducing weed growth

Mulching around landscape trees

  1. Choose the right mulch. organic mulches are preferred as they will break down overtime and provide landscape trees with nutrients. Wood chips, pine needles, hardwood and softwood bark, cocoa hulls, leaves and compost mixes are all types of organic mulch.
  2. Apply mulch during the middle of spring. Although mulch can be applied at almost anytime during the year, the middle of spring is ideal because root growth begins when soil temperatures rise.
  3. Use the right amount of mulch. Mulch should only be applied 2-4 inches deep to allow enough oxygen to get to the tree’s roots. If the soil around the tree drains poorly or if you are using finely textured or double-shredded mulch, only mulch 1-2 inches deep. Additionally, take note that finely shredded mulches will need to be replaced faster as they decompose faster.
  4. Evaluate old mulch. Before applying new mulch in the spring, check the depth of any existing mulch and determine whether or not you need to remove any before applying new mulch. Continuously applying old mulch over new year after year can have the same effects as applying too much mulch all at once.
  5. Mulch to the drip line. To fully protect your tree’s roots, make sure the mulch extends to the edge of the tree’s canopy or drip line.
  6. Keep mulch away from tree trunks. Mulch piled too high around a tree trunk can cause damage. When mulching around a tree, you should always make sure the root flare — the swelling of the trunk where it meets the ground — is visible.



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