During this warmer-than-usual January, I'd like to take a moment to discuss mulching. Utilizing a mulch ring around newly planted trees can be one of the best planting practices, but when mulching is done improperly, it can lead to decline and even premature death of the tree. I want to emphasize the benefits that a mulch ring provides to trees, how to properly install a mulch ring around a tree, and provide you with the steps in yearly upkeep for a mulch ring. If you follow these steps, your trees can be the happiest and healthiest versions of themselves, especially in some of our harsher Kansas landscapes.

 

Mulch rings mainly benefit the root systems and the bark of young trees. Research shows that mulch decreases weed growth, helps conserve soil moisture, controls soil erosion, and maintains a uniform soil temperature. A mulch ring also creates a physical barrier to lawn care equipment (like weed whips and mowers) from the bark of trees; often, this equipment gets too close and can detrimentally damage the tree. 

There are 3 main components to making a mulch ring: 

There are many types of mulch to choose from, but organic mulches are generally considered the best, including wood chips, compost, old hay, straw, or leaves. These mulch types promote the growth of beneficial fungi that help nutrient cycling for the tree. The optimal depth is typically between 2 and 4 inches. If the mulch is less than 2 inchesthick, then you aren’t getting the benefits of using mulch, and if the mulch ring is more than 4 inches thick, there is no oxygen availability for the soil or roots. 

 

The shape of the mulch should be a doughnut or bagel; this means that you leave space between the trunk of the tree and the mulch (about 3 inches); leaving the mulch in the shape of a doughnut or bagel. If the mulch is placed directly against the trunk, the bark can remain wet and start to rot. Mulch that is too deep near the trunk can also provide cover for rodents that feed on tree bark. A good guide to mulch width is to mulch out to the canopy or drip line. Standing under or near the tree, the drip line is the area where water drips off the farthest out branches and leaves. Typically, this area is somewhere between 3 and 6 feet on younger trees. Mulching at this distance helps trees establish deeper roots and provides better stability for the fully grown tree. 

To maintain mulch, I recommend doing regular check-ins. Check-ins should be taking the depth of mulch in various locations. You want the depth to be above 2 inches and ensure the bark is free from litter. Routine checks should be in the spring and fall. Spring checks should be made between March and May; applying in the spring helps retain soil moisture as temperatures rise and supports new plant growth. Fall checks should be made from September to November; reapplying in the fall helps insulate roots before winter. 

 

You should also check your mulch after heavy winds and rainstorms, as it tends to move during these events. For Kansas, this means you’re probably going to be checking your mulch about once a month. Periodically checking your mulch ring is essential to ensure that your trees continue to benefit from the mulch ring's advantages. Ensure that all three components of the mulch ring are present during the checks.

 

A properly formed mulch ring provides many benefits to trees, including insulating the soil and roots to minimize temperature fluctuations and moisture loss, and acts as a physical barrier from lawn equipment. Utilizing a proper mulch ring is crucial for growing healthy and happy trees in our harshest Kansas landscapes.

 

Below are a few resources if you'd like to learn more about proper mulching. As always, please reach out if you have any questions or need further guidance!

 

Northwest District Forester

(785) 706-8812