• from $19
I just found some really nice teak window boxes that come in many sizes, are well made of sustainable teak, and have a nice story behind them. The company is called Diamond Teak and they are a couple, Kevin and Christine Yardley, working out of Costa Rica and Pennsylvania, but Amazon seems the best way to buy from them (shipping is free if you have Prime). Time to get planting!
(Image credits: as linked above)