This is not a vegetable well known to most people. My first memory of the crop was when working on an organic farm in Kent England. We dug the roots and then washed them until it was too cold in the late afternoon when they would start freezing to the conveyor belt of the washing tub.
They have a nutty flavor and can be difficult to peel. I like them.
We bought 2,000 lbs from Route One Farms in Santa Cruz, some to put in our boxes last week and some to plant. The 1,000 lbs we planted went into beds exactly like we plant potatoes. They go in  one foot apart in rows 40" apart. They will grow tall and will probably flower. The flowers look like small sunflowers. The crop can be dug in October onwards but is best left in the ground until needed.