Oh, that new bed is going to look wonderful! I like scattering the spider types around, too. :-)
I've got an "island" bed in my back yard with spring bulbs (mostly daffs but a few others, blooms early to late) and daylilies. I didn't plan my plantings very well, in part because I started out with a lot of unknown color seedlings LOL... but I did put shorter ones around the outside. I'm getting Sweet Woodruff established throughout the bed as a groundcover, plus short hardy geraniums ('Tiny Monster') at one end... since there are several trees to provide partial shade, the sweet woodruff loves it.
OT, but on the subfloor, I would think you could sand it down... penetration shouldn't be deeper than a wood stain would be, and you can sand off old stain, so... Hmm, maybe try an enzymatic cleaner rather than the bleach after sanding if there's any smell left. I'm not certain, but I think painting might also help, especially if you used a good primer like "Kilz" -- it seems to me I remember one friend using Kilz to cover the smell left in the walls from heavy cigarette smoking.
