Our contractor mentioned putting linseed oil on our cedar. Does it have the ability to repel carpenter bees? This is a new home under construction in Arkansas. Thank you.
Linseed oil will not stop carpenter bees. Linseed oil is a good way to treat unfinished wood like cedar and it can help prevent early wood degradation (like cracking and rot). But don’t mistake the use of linseed oil to replace traditional, proven methods that work on carpenter bees. The fact is that wood bees love cedar and any home that has cedar siding, cedar trim or any cedar components on the outside is likely to be attracting all kinds of pests including wood bees.
The good news is it’s easy to repel wood bees – even from cedar. And you review our Wood Bee article, you’ll learn we have two sprays that can be used.
The first is Cypermethrin. This is a concentrate that’s mixed with water and can be sprayed over siding, overhangs, soffits and basically anywhere female carpenter bees are scouting looking to build a nest.
Treatments can be done as frequently as needed but most applications will provide 2-4 weeks of repellency.
We also have a paint/stain additive that can be applied when using either. You can add it to linseed oil too if you’ll be using it on your home.
NBS won’t kill anything but it uses plant oil extracts for an active ingredient that have been found to repel insects and when used on a homes exterior, NBS will repel wood bees too.
Basically you’ll add one jug to every 5 gallons of linseed oil applied and it should help deter bee activity for a year.
NBS can also be mixed with water and sprayed over the homes siding and any plants where wood bees are active.
Lastly, if you do ever get wood bee nests, be sure to dust their holes with the Drione Dust listed in our article. Using Cypermethrin or NBS to treat existing nests will NOT work at all.