Maybe lobelia.

Good idea Hostaholic...all I could come up with were things that were too purple or way way way to big!

Helen

I just hosted a wedding in my yard this summer and trying to time things to bloom is very difficult- there are so many factors. Grow lights aren't always the right spectrum for blooming plants so I would check that out too. I would have a Plan B ready to go such as buying a flat from a nursery and transplanting into my little pots. I was yanking out plants from my hanging baskets and popping in new blooming flowers right up the the day before the wedding- very challenging.

Boy, I grow lots of flowers, but that is a toughy., I think hostaholic hit on the best or maybe only one.
I was at an elegant wedding, hosted by well-off parents, that had pots everywhere, even centerpieces of 'Springerae-asparagus fern" in terracotta pots /w white mineral deposits still on them, They had sparsely glued one inch royal blue realistic silk flowers (small asters maybe), to the ferns. I thought they were real--I think they fooled me bacause they were so sparse. They were elegant and gorgeous. I have also seen terra cotta pots, with green mold on them, used.

I should have mentioned that you could mimic the mineral deposit with off white craft paint at the bottom of the pots.

why not try some annuals like Salvia Victoria, you would have to force them to bloom with fertilizer.
Good luck
Lynn

Thank you all for the suggestions! I've decided I'll try to grow some annuals from seed, and if they look wonky or aren't ready when I need them, I'll go out and buy some in flats. Nothing will be wasted because I can plant the ones I grew at home, and if it does work out it will be a special gift for our guests. I just figure that I have the equipment and space, so I might as well try it!

Right now I'm looking at a love-in-a-mist mix...is this a foolish endeavor? Anyone have any experience/advice? Also, Lynn, forgive my ignorance, but why/how does fertilizer force bloom, and what kind would I use for that? Thanks again!