The time to open your housing depends on whether you had martins in the past. The first martins generally arrive in late March or early April. Landlords that previously had nesting martins can open their housing at this time. However, if you are a new landlord trying to attract martins for the first time, this would be four to five weeks too early.
The reason that previously successful landlords can start when the birds arrive is that the birds are what we call "site-faithful." This means that once adult martins have bred successfully in a location, they will return to breed in that same place year after year as long as the housing is available and properly maintained.
