I heard placing mulch around my foundation may attract problems with termites? Do termites eat mulch or am I just being paranoid? It seems like a lot of people place mulch around the landscaping near their homes. Could that many people really be unknowingly welcoming termite infestations?
Sarah Flores (Orange County, California)
First of all just because many people in your area use mulch near their homes does not mean that you should. There is more to termite control than “To mulch or not to mulch?” but quite a few folks do increase their risk to termite infestations via their landscaping. Here are some considerations you should consider to adequately answer questions about mulch and termites:
- Prior Termite Infestations
- Local Termite Risk
- Slope and Drainage Near Foundation
There are also many other factors that can play into whether or not termites are attracted to mulch. For example, this article by Cornell talks about the conversion of destroyed trees into mulch during hurricane Katrina.
This mulch was then sold nationwide at Ma and Pa landscaping businesses and large chains like Home Depot and Lowes. Little did the average consumer (and likely the businesses) know that a good deal of this mulch was infested with Formosan Termites!
We’ll get into each of these in more detail.
Are there certain types of mulch that termites avoid? I heard termites stay away from cedar mulch?
Although termites tend to avoid cedar heartwood because its resins are natural toxins to them… eventually, these termite-repelling cedar resins will seep out of the wood. This is especially true when the wood is in contact with soil, moisture, and sunlight as is the case with cedar mulch.
So, for a period of time, cedar mulch can offer some resistance to termites. However, over time this will not hold true. How much time does that take? Well, it just depends on the conditions of the soil, weather, and mulch. The wetter the soil and weather, the quicker your cedar mulch will diminish in its ability to keep termites away.
Similarly, termites don’t seem to eat pine straw mulch. But, pine straw mulch does attract moisture, so it can indirectly attract subterranean termites. Some people rake their pine straw mulch to prevent it from trapping significant moisture in the soil. This might mitigate the risk of termites being attracted to pine straw mulch, but I still wouldn’t put it right by your house. Leave about a foot of uncovered ground around your foundation.
Is it okay if the mulch around my house comes into contact with the wood from my home?
If you live in an area that is at high risk for termites it may be best to err on the side of caution and just not place mulch near your home. If you live in a place like Arizona that has both drywood termites and subterranean termites, which makes your home more at risk to termites are more at risk of termite infestations, then you may want to just avoid using mulch in the yard altogether.
Does it matter how deep I mulch with regards to termite problems?
However, if you decide that there is a low risk of termites in your area through research and go with mulch anyway then it is recommended to only use a layer of about 2 inches of mulch and ensure there is around 8 inches between the top of the mulch and the wood sill plate of the home.
Termites and plants both love this ONE thing about mulch…
The problem with mulch is that the moisture that it helps retain which is loved by plants is also enjoyed by termites. In fact, mulch does not even have to be wooden to attract termites. It is often the moisture that termites are attracted to.
