If your grow area is 3X4 feet: Put a cage with a door around it. It can't be too hard to fence them out. I personally think the hatchet would be easier. Plant life vs. animal==you lose every time! Perhaps if the cats had more to play with of their own in the house? I had a grow outside, years ago. My puppies ate them at 12 inches tall. Guess all animals like to eat these plants. so, don't get a dog! pr