Avoiding Common Tree Mistakes

5 Factors To Consider When Mulching Around Trees

6 June 2023 by Chiara Brun

Choosing the right mulch for your landscape trees will help keep down weeds and prevent soil moisture from evaporating away. You have several options when it comes to choosing and applying the mulch.

1. Organic vs. Inorganic

The two main choices with mulch are between organic choices, like wood chips and pine straw, or inorganic options, like stone and rock mulches. For most landscape trees, organic mulch is the better option. Stone and rock mulches absorb heat, which can cause major damage to tree roots that are near the surface. It's also more difficult to rake leaves or remove weeds around trees with stone mulches, so generally, organic mulches are used.

2. Mulch Type

There are still choices to make among the organic mulches. Wood chips are the most popular, and they come in several options. Wood chips and bark nuggets are the largest and heaviest choice. They decompose slowly and don't blow easily, making them an excellent choice for use around trees. Wood shavings are lighter in weight, which means they often decompose quickly, so they are better used in annual flower gardens that are replanted each year. Pine straw can make the soil more acidic, so use it around acid-loving plants like conifers and certain maples. 

3. Color and Appearance

Wood mulches come in a variety of colors, depending on the type of wood and whether it has been dyed with an eco-friendly dye product. The most commonly available colors are shades of brown, red, or black. Brown tends to look the most natural, but red mulches can really bring out the deep greens of certain tree and shrub varieties. Black mulches also look striking, but they do absorb heat so shouldn't be used around trees with a lot of surface roots.

4. Lining and Edging

Weed-blocking landscape fabric lining is often used under mulch to further reduce weed growth, but it's not suitable for use around trees. The fabric can become entangled with surface roots and lead to soil compaction problems, so mulch around trees is typically applied directly to the bare soil. Installing raised edging around the tree is a good idea, though, as this contains the mulch and prevents weeds and grass from neighboring lawn areas from growing into the mulched area.

5. Application Depth

For the best weed control, particularly since there will be no liner to reduce weeds, a deep mulch layer is necessary. The mulch will need to be replenished annually because it will decompose, but the decomposing does provide nutrients for the tree. Mulch, particularly when applied deeply, should be pulled back so it doesn't touch the tree trunk.

Contact a residential mulching service to learn more. 

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