Q: Will mothballs hurt the soil in my pots if I use them as squirrel retardant?

A: It is possible the mothballs could contaminate the soil if water flows over them and the chemicals are dissolved into the soil. As for being a squirrel repellent, I think the only way this could work is if you use the mothballs as ammunition in a slingshot. The smell of mothballs has not been proven effective for animal control.