It’s that wonderful time of year again where temps are rising, life is coming back into the landscape, and people are thinking about how to improve the urban canopy around them. Well, maybe not that specifically, but we have the urge to plant trees. Whether it’s for Earth Day or Arbor Day or you just enjoy the act of planting, one of the hot topics is getting trees into the ground. That’s not what I’m here to talk about today, though.
As much as I love assisting communities with their greening efforts, getting the right tree in the right place, planting is not the only way to help grow the canopy around you. One of the topics that can be neglected is maintaining trees from previous plantings. Often, trees get placed in the ground, they are mulched, watered, and staked, then left on their own to make it in the world. New trees can take about 2-5 years to become established in their new homes and they could require assistance from us for much longer to thrive. Luckily, there is a simple activity to do assist trees, young and old.
Just like when they were placed in the ground, trees still benefit from mulch. Reapplying mulch benefits trees in multiple ways. It’s a natural way to prevent weeds and grass competing in the root zone and adds a protective buffer against mechanical damage from mowers and weed eaters. It will also help to maintain moisture levels in the soil as we transition into the hotter summer months. When applying new mulch, don’t worry about removing the old layer. It’s working its way into the soil around the tree adding organic matter, improving the quality of the soil.
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- Figure 1: Volcano mulching around the base of the tree. Photo credit Lindsey Purcell.
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- Figure 2: Correct application of mulch. Photo Credit John Bonkowski.
Add enough mulch so there is a 2–3-inch layer sloping away from the tree with at least a 3–5-foot radius around the stem (older, larger trees can benefit from larger mulch rings). No volcano mulching (Figure 1), make sure you also have around a 1-2-inch gap between the stem and the start of the mulch ring (Figure 2) to prevent unwanted root growth above ground and rot from excess moisture on the stem. Continuing this practice every year can help maintain soil moisture levels, while enriching the soil around your tree, maintaining a safety zone, and adding a nice aesthetic.
