So many people commented on my garden pools, that I thought I should post some of the instructions here. You can't just dump in dirt and plant, so here is what I did:
First, I drilled drainage holes about 6 to 8 inches apart all around the sides, not the bottom, about an inch up. This will let some water stay in the bottom, but not a lot of it.
Then I put in a good layer of straw that I had. Pack it down good.
Then I put in topsoil, and mixed in some garden soil and peat moss.
After I planted I put in a layer of straw on top for mulch. You can also use mulch in place of the straw, but I had the straw already and needed to use it. I have added a layer of straw once since the original planting.
I hope this helps and I will certainly be updating on the progress!