You can also plant Pelargonium geraniums (Martha Washington) plants near any areas you want to keep flies away.
Here's a story that was in the Seattle P.I.:
Got flies? Here's a beautiful way to repel them.
On my Friday evening "Gardening With Ciscoe Live" TV show on
Northwest Cable News, one of my callers wanted to know how to keep flies out of their house.
Other than using screens, I had little to offer as a solution. Then, by coincidence, the next caller happened to be an Austrian woman who offered that the real reason why Austrians plant pelargoniums (
Martha Washington geraniums) in their window boxes: They are an attractive way to repel flies.
I admit I was dubious, but decided to try it. Pesky little flies used to swarm in circles between my house and garage, embarrassing the tweetle out of me whenever someone came to see my garden. After I planted the pelargoniums, the flies disappeared.
Try planting a bunch of Martha Washington geraniums where you have fly problems. Even if it doesn't work, maybe the visitors will notice the beautiful flowers instead of the embarrassing flies.
Why do Geraniums Repel Insects?
Geraniums repel insects due to the oils that the plant secretes. One of these natural oils is citronella, which is widely used in bug repellants and candles to drive away insects.
The plant belongs to the genus
pelargonium and is commonly known to discourage mosquitoes, Japanese beetles, cabbage worms, rose chaffers and leafhoppers.