Kohlrabi sugars go to an enlarged stem. Energy in rutabagas, radishes, and turnips go to their roots. Kales and mustard greens spread their energy out into their leaves. Of course you can eat turnip greens, broccoli leaves, and mustard flowers, but as mentioned above, they aren’t the plant’s priority.

But regardless of the plant’s initial priority, eventually they all shift their priorities to reproduce, resulting in the production of tender spring flowering stalks called raab.