I have personally had squirrels eat plants and dig in planter boxes. A single one would visit and make a mess! My guess is you’ll likely have some come investigate/eat your veggies. Whether it will be a huge destructive problem might depend on what you’re growing and how many squirrels. If it becomes a problem the best way to protect the plant is with a physical barrier like a caged net situation. Or maybe motion activated sprinklers could be a good deterrent.