Squash will grow up along the fence. One squash plant can be planted per two squares--- if you have a trellis for the plants to grow vertically!
Even after seven nights of below 0 degrees AND plenty of snow (is it really almost June?) here peak out peas, spinach, lettuce and beets. The pea teepees are lilac boughs. Only concern with these is they may just sprout too!
Notice that the two front, centre squares in box on the right aren't filled? In order to grow potatoes, dig down to bottom inch of soil in square and plant four seed potatoes. As shoots grow, 'hill' by covering shoots.