Mulch is great for trees, but believe it or not it can cause problems too. The International society of arboriculture has some great recommendations about mulching.
Basically you want to mulch the area underneath the canopy of the tree from the trunk to the dripline with 2-3 inches of organic mulch. But if you choose a smaller ring (three to five foot radius from the trunk, let’s say) it is beneficial too.
When mulching trees, it is really important not to pile the mulch up against the trunk of the tree. This area of the tree needs to be able to dry out, and actually see the sun.
Choosing a Mulch
There are many different options for mulching materials. The cheapest – and probably most beneficial – is shredded wood mulch (like Cypress wood mulch), which breaks down rather slowly and lasts up to 3 years. Other options are:
- Bark chips
- Triple ground hardwoods
- Cocoa beans
*Although rocks are considered mulching material, DO NOT use them as mulch. As it turns out the benefits of mulch are not benefits of rock mulch. Rock mulch materials are heavy and can compact soils. Rocks readily change temperature, too, which can accelerate freeze/thaw cycles of the soil. And they do not hold water the way organic mulches do.