I have about 20 plastic, aquatic type (so lots of holes), baskets sunk into ground, that have Tulips in them (wanted to make sure I knew where all the bulbs were so I didn't damage/dig them up at some point). They're looking fab at the moment, but when they finish, I'll have lots of gaps. Can I double plant, so that I have something to fill the gap? Can I lift the baskets, lift the tulip bulbs, plant, say, Lillies, and put the Tulips back on top, and re-sink the baskets? I have done this with 1 large patio pot, Lillies underneath, and Tulips on top and it seems to work ok. Just not sure about this working in the ground. Or, would this work with Roses instead of Lillies? Has anyone else done this, or have any tips? Help and ideas greatly appreciated.