Wood Chips for Mulch

Wood chips work great for mulch! Why are they not used more often? That is a question I cannot answer!

Wood Chips for Mulch!

This picture shows some pine chips that have been sitting under my Screwbean Mesquite for several years. As you can see, they are not uniform in size or color – giving them a more natural look than the bark mulch you can buy in bags. I have several customers that want chips from time to time. When they mulch their trees with chips, the trees really respond with exceptional growth!

It is important when applying chips to make the layer only about 3-4″ deep and to be SURE to not pile the chips up against the trunk of the tree. I usually pull the chips away from my trees so there is a bare area of about 2-3″ around the trunk. Mulch piled against the trunk can cause stress to the tree and problems down the road… The tree can benefit if the chips are applied all the way out to the dripline and beyond! That could call for a lot of chips if you have large trees. But, that gets us to another advantage of wood chips over rock mulch – you can often get them for FREE from a tree service! You will either have to spread them yourself, or hire a laborer to do it for you, but the material costs nothing. Granite can’t compete with that!

A new Ironwood with wood mulch applied!

One reason we don’t see more people using wood chips as mulch is because there are landscapers who sell decomposed granite (rock) mulch who are spreading rumors about chips. I have heard that wood chips don’t work here in the desert because they “pull moisture out of the ground”. That is not true!

Dr. Mary Olsen, Specialist, Division of Plant Pathology and Microbiologyfrom Arizona State University (pers comm) stated that “I initiated a study here in Tucson that was done at the UA farm in 2000-2001 that showed that both large and small bark kept soil more moist and cooler than decomposed granite or the untreated control (statistically significant).  Unfortunately the student who was supposed to be doing the project did not complete his part, and I never published the results anywhere…”

There is also a great web article on using wood chips for mulch by Linda Chalker-Scott, Ph.D. MasterGardener, WSU editor, Extension Urban Horticulturist and Associate Professor, Puyallup Research and Extension Center, Washington State University Puyallup, Washington here which dispels many of the concerns about wood chips for use as mulch.

I will say, that I have seen wood chips wash badly during thunderstorms when used on steeply sloped terrain. I have used them on raised berms in my yard (picture above) and have seen no evidence of washing. However, this might be something you would want to consider with regard to mulch choice.

If you have a relatively flat area with trees, wood chips can be the perfect mulch!

If you would like to try some wood chips for mulch, give me a call and I will put you on my list. We will deliver them free if we are in the area (dump trailer accessible areas, no spreading included). We work all over the Valley, so if you can be patient for a little bit, I am sure we can get you some chips! You (and your trees) will be glad that you did!