Years ago were grew it and didn't have a problem of it 'taking over'.
If your growing it for its pungent roots try an elevated garden than you can pull the dirt away to trim the many roots down to 1 or 2 large roots only. That's the best way.
You'll find triming roots an almost impossible task if you plant at ground level...but you can still get some decent roots, just not big enough to peel before chopping up. The all white roots when blended give you a nice white color and smooth texture.
We brushed the smaller roots as clean possible since they were too small to peel with a potatoe peeler. When blended that will yeild a darker color and a very slightly woody texture horse radish.
Whew ...still takes my breath away just thinking about making it. T
Standing on it's own the plant is a handsome broadleaf about 16"-20' tall.
'a good cook cleans as they cook'...overheard Mom explaining to my sisters.