A trick you could try is to get some bread, break it up into sizable pieces and mix it with the strongest chili powder you can find, then scatter it around your plants, the squirrels mouths will burn and they run away never to return. This process doesn't harm them... it just tells them not to ever return lol and keep the process going until the squirrels stop visiting your garden.
If that fails theres always the BB gun ;)
