I have filled my three 4' X 8' beds and then picked up one each of watermelon & pumpkin (bigger jack-o-lantern type)seedling. I thought my boys would enjoy watching them grow, then eating/carving them. I have a large planter, maybe 10-12 gallons. I was thinking of planting both in there and placing it in a corner. Then train each to go opposite ways. Surface area of the planter is probably 16" round so I figure there's enough room for both as long as the vines go their separate ways. Anyone grown either in containers before? Any suggestion or cautions?