By Wendy Blair, Expert Gardener, Instagram: @505garden
If You Like It, Then You Should Put a Ring Around It… A Tree Ring
A tree ring, simply put, is a ring of mulch installed around the base of your tree. Creating a mulch ring around both new and established trees is one of the best ways to care not only for your tree, but also for the soil it depends on.
A mulch ring is a wide circle of organic mulch applied around the tree, ideally extending out toward the drip line — the outer edge of the tree’s canopy. This protects the root zone from the wide temperature fluctuations common in our high desert climate. Mulch helps keep roots cooler in the summer and warmer in the winter, reducing stress on the tree.
Mulch is also essential for retaining soil moisture. In our windy spring conditions and extreme summer heat, soil can dry out quickly. A proper layer of mulch helps conserve the water you apply, improving watering efficiency and supporting healthier root development. As organic mulch breaks down over time, it also improves soil structure and adds valuable nutrients. As an added benefit, a thick layer of mulch helps suppress weed growth.
How to Properly Install a Tree Ring
For best results, follow these installation guidelines:
1. Apply mulch at the proper depth
Install mulch in a consistent layer 3–4 inches deep throughout the tree ring.
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This depth provides optimal moisture retention and temperature protection.
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Thinner layers break down too quickly and allow weeds to emerge.
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Excessively thick layers can limit proper air and water movement into the soil.
Spread the mulch evenly and avoid compacting it.
2. Keep mulch away from the tree trunk
Always leave a 2–3 inch gap between the mulch and the tree trunk, creating a flat “donut” shape rather than piling mulch against the bark. Mulch should never touch the trunk.
This is critical because mulch placed directly against the trunk can:
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Trap excess moisture and cause bark rot
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Encourage insects and fungal disease
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Suffocate the root flare, which is essential for tree health
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Lead to long-term stress and decline of the tree
3. Extend the ring as wide as practical
Ideally, extend the mulch ring toward the tree’s drip line. Wider rings provide greater root protection and moisture retention. At minimum, create a ring 2–3 feet in diameter for young trees, and wider for mature trees.
Choosing the Right Mulch
We suggest using Soilutions Forest Floor Mulch installed at a 3–4 inch depth around your trees. Our Forest Floor Mulch is made from arbor-chipped wood and includes 10% Soilutions Compost for added nutrition.
Unlike bark mulch, arbor-chipped mulch does not float or wash away. Bark naturally contains waxes that repel water, making it more prone to movement. Arbor-chipped wood absorbs moisture and gradually integrates with the soil, helping it stay in place through wind and rain while improving soil health over time.
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Long-Term Benefits
A properly installed tree ring:
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Improves soil health
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Conserves water
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Regulates soil temperature
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Reduces weed competition
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Protects tree roots
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Promotes stronger, healthier tree growth
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Tree rings are one of the simplest and most effective investments you can make in the long-term health and appearance of your landscape.
