Wasps are usually an outdoor problem, of course, but it’s summer! A time when interiors and exteriors are far more open to one another.
Perhaps surprisingly, wasps are actually a beneficial insect. They eat virtually all pest insects and larva in your garden and lawn, and like bees, they are pollinators. But unlike bees, they are far more aggressive, and they can make a mess of your outdoor wood furniture, decks and fences.
So, the best thing to do to get the benefits of wasps without the downsides is to keep them from nesting too close to your home or chewing on your wood. And the trick we use for that is teak oil.
What is Teak Oil?
Various products are called teak oil. These products usually are made of tung oil, linseed oil, and potentially some varnishes or thinners depending on the product. This article from Canadian Woodworking has a good break down of the different types of oil. If you are looking for a more environmental product, you’ll want to look for “raw” and “pure” oils. Boiled Linseed Oil (BLO) has additives.
When protecting against wasps, we’ve used various tung-oil products.
Why tung oil works
There are two ways in which tung oil is effective: first, it conditions and moisturizes your wood and then cures to create a hard finish. With proper care and application (we’ll discuss that in next week’s post!), this will get rid of the slivers or bits of wood that peel off and allow the wasps to start chewing.
There is an additional effect we’ve noticed, which is that they just seem to hate it. I (Carmen) have looked for any definitive explanations for this, but I haven’t found any yet. So instead, here are our anecdotal experiences.
I am allergic to wasps, and so keeping them away is pretty important.
Earlier this summer, during wasp house-hunting season, we had four straight days of wasps getting into the apartment. On day five I knew I needed to take action. Out came the teak oil (I used Circa 1850 Tung ‘n Teak Oil) and a paint brush and I got to work.
I applied oil everywhere I thought they might be getting in. We live on the 9th floor of an apartment building, and they were clearly coming in through somewhere on the balcony.
I applied lots of oil on non-wood surfaces: the metal grill vent to the air conditioner, around the patio door, and on the bricks that I have as plant stands. Then I applied oil to my wooden furniture outside: on the underside of the bench and picnic table, in all the joints of the outdoor chairs.
While I was applying the oil, four wasps came flying towards the balcony, reacted like they had hit a glass wall and veered away.
We have had no wasps come past the railing since. Our neighbours have had wasps all summer, and there are several visible wasp nests on some of the buildings balconies. Sadly we have not had bees either – we have flowers and usually get bees. We have had butterflies at the same rate as other teak free years.
We’ve been using this trick since we lived in a second-floor apartment with a large balcony. Wasps had begun building nests under out outdoor chairs, and so drastic measures were taken. The next year, we treated the chairs with tung oil, and the wasps did not build any more nests on our chairs or balcony.
When we bought our current home, one of the things we loved about it was the front porch. There is a lot of wood on the porch, and in our first summer we saw that wasps were flying into small holes in the ceiling of the porch.
We applied tung oil liberally to the ceiling of the porch, and also treat our outdoor furniture. The wasps left the ceiling alone, and have not built nests in any of our common areas.
How to apply teak oil
If you are applying it to wood, it can have an effect on the colour, so you should try a test area first. If you are using it mainly for finishing, then come back next week for a full explanation of the process of sanding and applying the oil.
For wasp repelling, you can stick to undersides or out-of-site areas. You can do a little light sanding to raise the grain, but it’s not as important. Do cover holes or little places that might offer the kind of cover they want for their nests.
Tung oil can take quite a while to cure, so be aware of that if you are applying it to surfaces that you interact with (like seats or arms of chairs). It may feel tacky for a while.
If you are applying to non-wood surfaces (like the air conditioning grate), be aware that this is not a recommended use. If you care about the look of the item in question, make sure you do a test patch.