Assuming that termites don’t eat cedar, many homeowners prefer cedar mulch and cedar construction lumber. This assumption is partially correct, but you should be aware that there is some nuance to termites’ relationship with cedar wood.
Termites can eat cedar, but do they normally eat cedar?
Termites can eat cedar but they tend to stay away from it because cedar wood has resin and oil that tends to repel termites.
Some scientists have found evidence that cedar resins are toxic to the termites that decide to ingest them.
However, as with all wood and even lumber, resins and sap seep out of the wood over time.
This process is expedited when cedar is exposed to the elements. In the video below you can see termites in the stump seem unaffected by the cedar resins that are toxic to them.
Why is that? Well, you can also see by the condition of this stump that quite a bit of rot has already taken place. My guess is that the poisonous resins are no longer present in the wood and this cedar stump is obviously no longer resistant to an infestation.
Why Do Termites Avoid Cedar?
Scientists observed that cedar was not only repelling termites but also toxic to the termites who did try consuming it. Because of this cedar is a great type of wood to use for certain parts of construction projects.
Cedar is actually one of the more expensive types of lumber to use for construction which makes it impractical to use for the entire structure. Additionally, it would be nearly impossible to remove and replace some of the structural lumber with cedar since doing so would require demolishing significant portions of a house. Because of this, some termiticide companies are attempting to develop ways to emulate the repelling capability of cedar to treat normal lumbar. As of now, no such chemical has been developed but there is an alternative chemical that is often applied to wood to achieve a similar effect.
Borate Wood Treatment As Alternative To Cedar
The most common chemical used to treat lumber to make it resistant to different wood damaging insects is borate. There are several borate-based solutions on the market but the active ingredient in all of them is borate. Borate is usually applied to lumber prior to the construction by either brushing it or spraying it onto the wood. It can even be mixed in with paint and applied to the siding of a home or a wooden fence.
However, it is sometimes used after the fact as well in spot treatment procedures. In these instances, an area infested by termites is identified and the borate mixture is injected into this area through drilled holes.
Some borate companies claim that borate treatment will last the life of the wood and that it not only protects against termites but also carpenter ants, wood boring beetles, and even wood-eating fungi.
Are There Other Types of Wood Naturally Resistant To Termites?
There are other naturally termite-resistant woods that seem to naturally repel termites including redwood and cypress. However, like cedar wood, these may keep termites away but the wood itself tends to begin breaking down sooner and do not last as long as other types of wood.
What About Mulch? Is Cedar Mulch A Good Choice?
Yes, for mulch cedar is a great choice although you should still replace it as it begins to age and rot to keep termites away. Also please keep in mind that even if termites are repelled by the resins in mulch it still can be harmful if you pile too high it around your home.
Always place your mulch near your home in such a way that allows for proper drainage because termites are attracted to damp material. If your mulch is emplaced in such a way that the soil near your foundation begins to accumulate moisture you may be creating prime conditions for subterranean termites to begin building a nest underground.
Remember subterranean termites typically thrive on two things: moisture and cellulose material. The video below demonstrates this concept by showing termite mud tubes they build when leaving the ground to protect themselves from drying out.