A few days ago I was looking out my kitchen window as I was doing the dishes and I noticed a few wasps hanging around and then disappearing under the wood railings of the deck. I thought, I bet the peppermint and/or lemongrass would prevent them from building their nest there.
So I grabbed our sprayer bottle and filled it with 1/2 vinegar and 1/2 water (about 8 ounces in total) and then added about 4-5mls of peppermint and 4-5mls of lemongrass (did not really measure, just wanted to make it really strong), gave it a good shake and went outside to see where their nest was. Sure enough they were building a small nest under the wood railing. So I sprayed the nest and the 2 wasps flew away from it. It has been about 5 days and they have not returned!
I ended up spraying all under the railings and in other parts of our property that have wood and signs of wasps building nest. Voila, no more wasps building nests on our deck or on the decks of our out buildings. Lesson learned: Wasps do not like peppermint and/or lemongrass!
I will continue to spray every couple of weeks just to keep them away from building nests.