Fleas like temperatures below 95°F with humidity above 50%. As usual, it’s better to prevent them than to remove them. Fleas are brought in by urban wildlife like rabbits, rats, squirrels, raccoons, etc. If you feed the bird you’re also feeding the critters (with the fleas!!) that visit the bird feeders. So, if you have a flea problem and feed the birds, stop feeding for a month or so to get the problem under control.
If you have fleas, treat the yard and your pets, see the section “Fleas on the dog/cat”. You need to treat both the yard, the pet and the house within a 24 hour period. When fighting fleas it is all about breaking the life cycle. There are a bunch of all-natural and synthetic products to choose from. Most products will take more than one application, 5 to 10 days apart to break that life cycle.
Our number one product for outdoor flea control is sulfur, but remember it is a repellant, not a killer. There are two types of sulfur, powder and granulated. Application rates vary but the following have worked well for me. Use 10# to 15# of granulated sulfur to cover a 1,000 square feet and should be reapplied every 10 to 14 days depending on the weather. Five pounds of powdered sulfur will cover about 1,500 square feet and should be repeated weekly.
The all-natural product called Yardsafe from the folks at Cedarcide is a high concentration cedar oil product in a ready to use quart that will cover about 2,000 square feet for the initial application. Repeat application in 5 to 10 days. This will kill the existing fleas and has a good residual for several days afterward depending on the weather.
There are also quite a few choices on the chemical side in both liquid and granulated. A good rule of thumb is to pick products with an active ingredient that ends with the suffix, “thrin”. Some of the most common are bifenthrin, cyfluthrin, permethrin and my favorite product, lambda-cyhalothrin, is the active ingredient in Cyonara. This quart attaches to the hose and will cover about 8,000 square feet. As always please read and follow all label direction.