I didn't get to try it last spring, so I'm again going to be on the lookout for fresh water chestnuts at the Asian market to try to grow in the little rice paddy or bog garden, though I may also look for actual nursery stock. I'm thinking of growing Hmong Sticky rice instead of Koshihikari this year.
Two other exotics on my list are Japanese wasabi -- found sources last year but gave up as too expensive -- maybe I'll consider it again. If I get set up to grow wasabi, then I'll definitely also grow watercress. And Biwa fruit (I just drew a blank on it's common name ... Starts with a "L" I think -- oh yeah Loquat.)
The fruits should be available at the Asian market, if at all, in March, same as Water Chestnuts. I want to try planting the seeds.
I have regular chestnuts from the supermarket that may be sprouting -- some are planted indoors and some are in moist compost/sand mix in a hopefully protected area in the garage. I'm also trying to grow Sansho from seed. Other on-going projects too that I've mentioned elsewhere.