Kohlrabi is one of the best kept secrets in the gardening and microgreens world. Not only is it very easy to grow but it is a nutritious vegetable with a delicious celery like nutty flavor. It is a cool weather crop that tastes best when it matures during the cooler temperatures. Because of this as well as a reduced problem with insects, a fall crop is preferred but can be grown as a spring or fall crop. Kohlrabi is a perennial or biennial. But it's grown and harvested as an annual crop. Sometimes known as German Turnip. Related to cabbage. Kohlrabi has a short growing season.