The best solution I have found for keeping bees and wasps away from hummingbird feeders is mint extract of some sort. After I wash the feeders, and before I fill them, I take a Q-tip, dip it in the extract, and apply it to the ports. I also apply to the edge where the bottle comes in contact with the bottom, and, if applicable, along the seal created when putting top and bottoms together.
This simple solution worked the first time I used it and has worked ever since. Using extracts can be costly. My tiny bottle lasted for over three years, and yes, it froze during the winter months.
I haven't tried rubbing fresh mint leaves to the ports, etc., but I am sure this would also work.
Source: I cannot recall exactly where online I found this solution. Perhaps hummingbird(s).net
By leeanne collins from Clio, MI
Any kind of mint extract can be used. I used peppermint extract at first but had to purchase mint when peppermint was no longer available.
BTW, this deters bees, wasps, and yellow jackets.
I tried unscented wax around the flowers on the feeder and that helped but then I tried the peppermint oil and it is amazing. I apply it with a cotton swab lightly occasionally and the bees won't even land and the hummingbirds are free to feed. When bees start landing again refresh the oil
I just took a Q-Tip soaked with peppermint oil & rubbed it on top of the feeders, away from the ports. The wasps, who had taken over, are nowhere to be found. Worth the money to invest in the oil & it's not harmful for the birds.
gardening-for-life.com is a site that uses info from the Audubon Society. Mint is a food source. Hummers are ok around mint.