I've tried growing lobelia, alyssum, and petunias in those holes and they didn't like it at all. I did have some volunteer gypsophila muralis do ok in them last year, tho. Oh, and a lone dianthus survived in one for a couple of years. I'd love to be able to grow something in those holes, because I do like using the blocks for making raised beds. Anyone got specific suggestions for things that would do well? Maybe one of my problems is that I have the blocks sitting on another non-porous surface; might do better if they were sitting directly on the ground?
