Do you have any areas of tall grasses in your yard? That's prime tick habitat. If so, cutting it down might keep the ticks out of the yard. I got nuthin for ya natural that I know works, but I do know of a few things that people try. Nature's Farmacy makes an all-natural product called Flea Flee that's made of essential oils.
http://www.naturesfarmacy.com/store/details.php?prodId=102&category=
I've heard about diatomaceous earth for pest control before, but idk at all if it works.
That's all I got
