A fence is your best defense but there is also a liquid spray that will deter pests with the smell made by a company called Hinder. You can try a home version by sprinkling red pepper flakes in the area. Cats do not like to dig where you place flat chicken wire on top of the soil and wire tomato cages can protect newly planted treasures from roaming dogs. Catching a dog in the act of trespassing and scolding the animal can also help to establish your territory and remind the animal not to trespass. Keep growing, Marianne Binetti