squirrels storing walnuts

walnuts in odd places
One year I planted tomato plants in pots. The dirt was left in the pots from the year before and I added new potting soil.  At first the plants looked good, then the leaves started to curl.  I finally took them out of the pots and put them in the ground hoping to get a few tomatoes.  When I did that I found walnuts in the pots, not very many, but it must have been enough to poison the tomato plants.  

When I came home from a recent trip I saw the squirrels were working while I was gone.  They are funny, they lodge the walnuts anywhere they can.  I have to remember to dump my pots next year and take out all the walnuts so my plants do well.