I've had good success with Borax in a house, heavily; I'm sure boric acid powder or the roach products that are boric acid would work but might be more expensive. Don't know how much good they would do outdoors if it rained, though. I once sprayed a large yard with some anti-bug stuff out of a hardware store and a two gallon pump sprayer. It was not a complete solution, but it killed a huge number and got them down to where we could control them simply with flea products on the dogs and cats, and maybe one additional yard spraying. I'm not much on these nasty chemicals, but there are times.... We were infested both in the house and yard til we did this, and got it under control.