Kohlrabi (from the German for cabbage turnip), also called German turnip, is a biennial vegetable, a low, stout cultivar of wild cabbage. It is the same species as cabbage, broccoli, cauliflower, kale, Brussels sprouts, collard greens, Savoy cabbage, and gai lan. It can be eaten raw or cooked. Edible preparations are made with both the stem and the leaves. Despite its common names, it is not the same species as turnip.
Kohlrabi has been created by artificial selection for lateral meristem growth (a swollen, nearly spherical shape); its origin in nature is the same as that of cabbage, broccoli, cauliflower, kale, collard greens, and Brussels sprouts: they are all bred from, and are the same species as, the wild cabbage plant
The taste and texture of kohlrabi are similar to those of a broccoli stem or cabbage heart, but milder and sweeter, with a higher ratio of flesh to skin. The young stem in particular can be as crisp and juicy as an apple, although much less sweet.
I have grown and harvested kohlrabi in my backyard vegetable garden. They are cold-weather plants for the winter garden, but kohlrabi seems to tolerate the desert heat quite well. Like most cabbages, stagger their sowing every other week over several months that you don't get a glut of cabbages all at the same time.
I don't seem to have any pictures of using this in any recipe. I assume they went in a mixed vegetable soup.
Pic1: kohlrabi in my vegetable garden — 2014-07-21