Galvanized tubs with wooden legs added...what a great container planting idea! I think I would like some kind of round wooden base with casters so I could scoot them around. That's my complaint with my wine barrel raised beds!
In the fall - plant spring bulbs in pots. Store the potted bulbs in an unheated garage or storage room. Youll need to water every few weeks since the pots wont have access to rainfall. Pack bulbs shoulder-to-shoulder in big containers for an abundant display in spring. Toss aside the spacing recommendations so you can get as many bulbs into the container as will fit.