A common practice for homeowners is the addition of tree ring landscaping to their yards. Whether it be a perfect circle of mulch contained by metal or plastic edging, a store-bought mulch mat, or a mini garden encircled by bricks or stone, tree ring landscaping has boomed in popularity in the past few decades.
But is tree ring landscaping bad for your trees? What’s going on beneath the surface?
In this article we’ll cover the popular types of tree ring landscaping, and break down the pros and cons.
What is Tree Ring Landscaping?
Tree ring landscaping refers to the practice of adding a border around the trunks of trees to separate that area from the nearby elements, such as a lawn or natural area. Tree rings are primarily used for the purpose of keeping down weed growth, retaining soil moisture, and protecting tree trunks from unintentional damage by lawn equipment.
Additionally, some people choose to add flowers and plants within the ring to add color/visual interest to a particular area.
Popular types of tree ring landscaping include:
- Borders of natural stone
- Borders of brick or paving stones
- Borders of wood
- Plastic or steel weed barriers (edging) driven into the ground
- Tree ring protector mats
- Patios or decks built around trees
Do Tree Rings Hurt Trees?
Tree ring landscaping can indeed hurt your trees, if done incorrectly. There are several things to be wary of when planning any sort of landscaping around the trunks of your trees. Here are 4 things you need to take into consideration when it comes to tree ring landscaping.
1. Beware of Damaging Tree Roots
The first thing every homeowner should be aware of is that your trees’ roots may not be very deep, depending on the species. Any time you dig in the soil directly beneath your tree’s canopy, you run the risk of damaging the root system.
If you’re intent on planting beneath your trees, use a hand trowel instead of a shovel, and be gentle. If you encounter a root, move on to another spot.
2. Avoid Raised Beds Around Trees for Proper Oxygen Flow
Some people think it’s best to build a raised bed around their trees to avoid digging at the roots. Many tree experts warn against this practice. By piling soil and/or mulch too deeply over an established tree’s roots, you’re making it difficult for oxygen to penetrate.
Oxygen is necessary to the tree’s roots to enable photosynthesis. A tree may suffocate if the root system cannot breathe.
3. Watch Out for Soil and Mulch Contact with Tree Trunk
Another potential issue is the proximity of soil and/or mulch to the trunk of the tree. Soil or mulch that comes into direct contact with the bark or buries the root flare (the wide area where the root system and the trunk meet) will soften the inner bark and promote fungal disease. The softened bark will allow pests like carpenter ants and termites to penetrate and further damage the tree.
Always leave 3 – 5 inches between the mulch and the trunk of young trees. Increase that space to 8 – 12 inches for mature trees.
4. Avoid Volcano Mulching for Healthy Tree Roots
The most common mistake you may see in nearly every neighborhood, is the practice of piling mulch high against a tree trunk, forming a hill. This practice is called volcano mulching, and it is definitely not a good idea.
Never pile mulch thicker than 3 – 4 inches, and never bury the root flare. Often times, a tree subjected to volcano mulching will send out fine-feeder roots which pop out of the mulch, in search of oxygen. Unfortunately, these roots are vulnerable to conditions like drought and freezing temperatures.
The more fine-feeder roots above ground a tree has, the more danger the tree will be in when they fail.
How Does the Landscaping Material Used in Tree Ring Landscaping Affect Trees?
There are ways to safely incorporate tree ring landscaping in your yard. If you’re careful not to disturb the roots, use caution when adding soil and mulch, and leave a space between the trunk and the added material, you can certainly landscape around your trees.
When choosing a landscaping material, you should consider how the following materials may impact your trees. Lets take a look at each landscaping material below and learn exactly what they can do if used around your trees.
Wood Mulch
Wood chips or bark, spread in a 3 – 4-inch layer, makes for a relatively good landscaping material around trees. On a positive note – as the chips break down, they feed your trees. The downside is many bugs are attracted to wood mulch, unless you use cedar, which may be expensive.
Rubber Mulch
Rubber mulch is not a great option, unless it’s for a very short period. Rubber doesn’t allow water or air to flow through very freely, it heats up in the sun, potentially harming your tree’s roots, it’s highly flammable, and chemicals will leach into the ground over time, which are toxic to plants.
Rock Mulch
Rock mulch can be very pretty, but it comes with its own issues. It doesn’t allow air or water to penetrate evenly, the weight will compact the soil over time, and it doesn’t offer any benefit to the tree, as it never breaks down.
Rock also heats up in the summer and can retain heat even after the sun goes down. In hot climates this is not ideal. Also note that some forms of landscaping pebbles are treated with herbicides to help you minimize weeds when used for walkways, etc. Over time, these pesticides will wash into the soil and may harm your tree. Check the label carefully.
Flower Beds
Raised flower beds usually require a depth level of soil that is potentially harmful to your tree’s roots, by depriving the oxygen flow. Consider placing containers on top of a mulch layer, instead, or using a decorative, flowering ground cover that doesn’t require a raised bed.
Stone Ring Kits
Stone rings may work well for a newly planted tree but be aware you may run into trouble with an already established tree. To make the ground level enough to build a proper wall around an established tree, you’re undoubtedly going to be faced with roots that are in the way. You may be tempted to cut through them.
Don’t do it! In either scenario, if you layer too much soil or mulch in that deep well you’ve now created, you may run into issues as the tree roots become depleted of oxygen.
Steel or Plastic Weed Barrier Edging
When used around a new tree planting, an edging that is driven 4 inches into the ground can spell disaster. Trees with shallow root systems will reach the edging and circle, instead of going underneath.
This can stunt the tree’s growth. It’s best not to drive barriers into the ground within the calculated drip line of the future mature tree. When using edging to circle an already mature tree, be sure to not use it around trees with shallow root systems, for fear of damaging them.
Certain trees like white oak, hickory, sweet gum, and some pine trees can tolerate subterranean edging if done with care.
Landscaping Fabric
Although using permeable landscaping fabric under mulch will help to keep some weeds at bay while still allowing water to pass through, the problem is that the fabric prevents organic material, such as fallen leaves, twigs, seed pods, and mulch from breaking down into the soil, which depletes the tree of nutrients.
Are Certain Tree Species More or Less Prone to Risks in Tree Ring Landscaping?
Although any species of trees can be harmed by careless tree ring landscaping, several varieties are more at risk because of their shallow root systems. These trees include:
- Beech
- Cherry
- Plum
- Dogwood
- Magnolia
- Holly
- Maple
As these trees all have roots close to the surface, you must take care not to injure them by digging, or by layering soil or mulch too deeply. It’s best to use shredded leaf mulch over wood mulch on these varieties, as oxygen can flow through shredded leaves more freely.
Great care should be taken to avoid harming the roots by digging. Consider this before planting accent plants.
Are Tree Ring Protector Mats Safe for Trees?
A minimalist, but popular option in tree ring landscaping is the use of a store-bought circular mat, which encircles the base of the tree. It is not covered by soil or plants but exists only to keep down weed growth and retain moisture, and in the case of organic mats, potentially offer nutrients to the tree as it breaks down.
Types of tree ring mats include:
| Mulch Mats |
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| Weed Mat Rings |
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| Rubber Mat Rings |
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Tree ring mats may make your weeding easier, but even organic varieties have many drawbacks. All tree ring mats can inhibit oxygen from reaching your tree’s shallow roots, they may provide a haven for insects which burrow beneath them, and often lend a consistently wet atmosphere to the underlying soil, which can lead to root rot and fungal disease.
If using a tree ring mat, never layer soil or mulch on top of it. This will compound the problem.
A ring of loose, natural mulch is actually much healthier for your tree, although it does require more upkeep such as weeding, and neatening up the edges from time to time.
Can You Build a Deck or Patio Around a Tree?
Yes! A great alternative to cutting down a lovely tree to build your leisure space is to incorporate the tree into your plans, building around it. A tree will provide welcome shade and beauty to a deck or patio area.
The natural gaps in decking will allow rain and oxygen to flow through. It’s best to consult an arborist before you build, and make sure to cover the following issues.
- Is this tree in good health?
- Can I dig around the roots? If so, where?
- Does my tree drip sap, or excessive debris that will ruin my deck?
- How large will this tree grow? (plan to expand the box around your tree over time)
- Does this tree have any seasonal offensive odors? (Bradford pear, ginkgo, Chinese chestnut and others have seasonal aromas most people don’t care for)
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If you decide to go ahead with your plans, be sure to never use chemical solutions to wash or treat your deck, lest they poison your tree.
Are there Any Safe Landscaping Ideas for Around Trees?
The best way to keep your trees happy is to mimic the way they grow in nature. In a forest, mulch is a natural occurrence when organic matter, such as leaves falling from the trees, breaks down.
You never see heaped up piles of mulch suffocating trees, and in fact, most of the leaves fall a few feet away from the trunk, under the edges of the canopy.
Your tree will certainly appreciate a thin layer of organic mulch to feed it and protect it against temperature extremes. Weeds are another matter altogether. If you’re looking to totally eradicate all weeds popping up around your trees, you’ll be doing so at the expense of the trees’ health. To completely smother the weeds by blocking the light will also likely rob your tree roots of oxygen.
Consider other methods of prettying up the landscaping around your trees, without using a raised bed or border structure.
- Decorative ground cover plants such as oak sedge, white wood aster, Hakone grass, and yellow root work well under dense canopies, while sunnier locations can support cutleaf stephanandra, mountain mint, wild bergamot, and bush honeysuckle. When planting ground cover, separate them into 2-inch plugs to minimize digging around tree roots.
- Bulbs or perennials under a thin layer of mulch – will minimize your digging around tree roots.
- Flowerpots and planters in a variety of shapes and sizes.
- Benches, swings, or other pieces of outdoor furniture
Michelle Weaver is a former pastry chef of thirty years who reinvented herself during the pandemic, now happily earning a living through freelance writing and selling her art. She and her significant other live in an 1895 farmhouse in North Carolina, where they have several acres, allowing her to garden to her heart’s content. When she’s not playing in the dirt, she enjoys hiking in the nearby mountains, creating new vegetarian recipes, and photographing the wildlife that comes to visit.