Highly suggest chicken fencing to put around your plot. Try hair trimmings or even dog or cat fur. Also this has worked for some (but not everyone) but if you get stove top liners and hang them around your plants it might create enough noise to scare off the animal because they aren't used to certain noises.
Dig holes and place the pots in those then place a "mat" of chicken wire on the ground to keep the animals from digging...it sounds to me like you have bone/blood meal in your soil and coons are digging at them...or squirrels looking for nuts :-/ if you have blood/bone meal in your soil try taking panty hose and adding some in those wetting it and hanging it from a thin tree branch away from your plot...this will help attract coons away from your plots and the branch should be thin enough to keep them from climbing on it and it should be high enough to keep coyotes or other animals from jumping for it. Soap will help keep deer away, also try synthetic predator urine such as wolf or coyote...kept deer out of my plot...also try fishing line around your plot.
On a side note... If you want to keep them in the pots and not dig at all you could take the chicken wire and have extra length and use tent spikes to secure the c-wire to the ground to help keep the coons from knocking over your plants pots.