The right way
- Make a ring at least 3 feet wide around the tree. Wider is better, out toward the drip line if you can.
- Spread it about 3 inches deep.
- Keep it about 3 inches away from the trunk, so the base of the tree, where it flares out, stays visible.
- Shredded wood or wood chips work well and break down into the soil.
The mulch volcano
Mulch heaped up against the trunk in a cone is one of the most common landscaping mistakes. It keeps the bark wet, which invites rot, insects and disease, and it can lead the tree to grow roots that circle and strangle the trunk. Trees can decline for years before anyone connects it to the mulch.
If a tree already has a volcano, pull the mulch back from the trunk until you can see the root flare.
Why it helps
- Holds water in the soil, which matters most in a drought
- Keeps the soil cooler in summer
- Keeps grass from competing with the roots
- Keeps mowers and string trimmers from wounding the bark
Sources
- Missouri Department of Conservation: watering and mulching trees through drought
- University of Illinois Extension: mulch volcanoes slowly kill trees
General information from public sources. Show Me Tree Pros is a directory, not a tree company; for a specific tree, have a professional look at it.