Mulching and Edging Around Trees
By John Stonaker, Jan 17 2020 06:11PM
Whether your property is commercial or residential, your trees could benefit from edging and mulching. Mulching insulates the soil, protecting the tree from cold, and retains moisture, keeping the tree hydrated during the heat of the summer. Mulch also discourages weeds that compete with the tree for nutrients. Adding an edging can help retain mulch, prevent lawn creep, and protect the tree from damage caused by lawn mowers.
While mulching and edging are beneficial to the tree, it’s important to avoid common mistakes that can actually damage the tree. One of the most common mistakes is to create a mulch hill, sometimes called a “mulch volcano” around the tree. You’ve surely seen mulch piled high under trees. This application certainly discourages weeds, but it also suffocates the tree’s roots, which then grow upward instead of downward in search of nutrients and water.
Piling mulch against the trunk turns the advantages of mulch against the tree; its insulating and moisture-retaining properties encourage rot and create a welcome home for insects. Piling mulch against the tree is very common with mulch hills. Some landscapers will create a donut of sorts around the tree, trying to keep the mound away from the bark of the tree, but rain and natural settling cause the mulch to eventually drift down to the trunk.
Raised beds around trees are beautiful, but they usually include the two problems listed above. In addition, they usually have plantings in the raised bed, causing additional competition for water and nutrients. For a mature tree with a large canopy and roots well established deep in the ground, a raised bed with an inner wall that keeps the bed at least two feet away from the trunk could be created with less risk of harming the tree.
How to edge and mulch correctly
Determine the size of the mulched and edged area you want. Laying a garden hose or using landscaping spray paint to mark the area will help you maintain a nice form. Be sure to think carefully about traffic patterns, future growth of the tree, and neighboring plants before deciding on the size and shape of the edged area.
Carefully remove 2-4 inches of turf, avoiding damaging any roots. If you are removing a deep mulching that has been in place for several years, you will likely come across many small roots, and possibly larger ones. If you discover roots or suckers, we recommend you get help from a trusted tree specialist—not a regular landscaper—who can help you remove the roots without hurting the tree.
Do not remove much soil around the trunk itself – remember, you will not be laying mulch within several inches of the trunk, and you will not heap the mulch above ground level, so let the surface of the ground taper gently up to the trunk.
Once the area is cleared, you may choose to add an edging. You can choose from a variety of materials that will complement your landscape and your style, including rocks, bricks, and fabricated edging.
Fill your edged area with the organic mulch of your choice: pine needles, bark, wood chips, composted leaves, or other commercial mulch. Make sure the organic mulch is fully matured, not fresh, as it will create heat as it decomposes.
Maintain your mulched area by occasionally raking to prevent packing, and replenish every year or two as it slowly decomposes.
Feel free to reach out to us here at Stonaker for your tree needs. We service central New Jersey and surrounding areas.