Buckwheat is used in some parts of Ladakh as a second crop after barley, in the longer-summer parts of Ladakh. I don't think anyone here has mentioned, buckwheat is really one of the most delicious leafy greens! I think it would be worth growing for a short time, cutting off for leafy greens and leaving the roots (to rot or be plowed in or sit over the winter).
Here especially where buckwheat grows as a garden or field weed, it is collected in late spring or early summer as part of normal weeding. You can cook the leaves immediately or dry them raw to cook in the winter. The dried leaves are very dark green, with an attractive silvery spotting or sheen on them. As a cooked green they are really the smoothest one and have something very yummy in the mouth about them. (If you like cooked greens).
The only greens I like better are caper greens, which require processing and retain a slight caper flavor. Spinach, swiss chard, some kind of mustard greens, and some kind of lettuce are the leafy greens that are cultivated and cooked most here, but buckwheat leaves are hands down more yummy than the rest. Here we cook buckwheat leaves up when we have to host a
vegetarian dinner in the winter -- it's the kind of goody you save for guests.