Problems Using Maple Tree Chips & Mulch

Application Methods

• Do not apply maple mulch or wood chips directly around the base of plants or trees. Doing so reduces oxygen and moisture to the plants and may suffocate them. Additionally, mulch may provide hiding places for voles or mice that feed on the plants.

Sour Mulch

• When maple --- or any other wood mulch --- is stockpiled during storage, the pile may develop anaerobic conditions, meaning that oxygen doesn't permeate the interior of the pile. As a result, the pile may produce chemicals, such as acetic acid. The mulch will kill plants if it is applied to the soil. Avoid mulches that smell of vinegar, ammonia or silage. If you inadvertently purchase sour mulch, spread it on a patio or driveway for a day or two. The acetic acid will leach out of the mulch, making it safe for use on plants.

Fungus Problems

• Thick layers of mulch may develop fungus that form a mat, reducing the availability of water to plants. Plants may wilt or die as a result. Apply mulches no thicker than 3 inches deep. Artillery fungus and slime molds may also grow in mulches. Slime molds do not cause damage, but artillery fungus can cause brown or black spots on hard surfaces, such as house siding and plant leaves. Rake the mulch occasionally to reduce these problems.

Nitrogen Deficiencies

• All organic mulches, including wood chip mulches, decompose when placed on the soil. This natural process improves soil over time, but during the early stages of decomposition, maple wood chips may take nitrogen from the soil. Fertilize plants with blood meal, manure or urea before adding maple mulches to prevent nitrogen deficiency.