I freeze mine. Grow my own. And be careful where you plant it, lol. Mine was, oh so dumb, planted near my blueberries....i just accepted the mistake and it has somewhat grown together in harmony. I freeze the whole roots when busy harvesting and lazy. Some i peel and chop in chunks, soak in vinegar 24 hrs, then freeze. Some i process coarse, some fine like cream. It freezes great. I don't find too much change in texture. But i use it in mustards and for cocktail sauces and even the finer cream gets a re-wiz in the blender. I even freeze fresh fridge pickles when the persians are on sale all winter and my own harvest early fall. As long as you give your fresh horseradish a 24hr marinade....the purchased should freeze fine also being 'pickled'. I would remove it from the grocery glass container....may not have expansion room. But like mentioned, it will keep a fair time in the fridge if not opened.

I do rhubarb in containers - large 55 gal plastic barrels cut in half - and it does well for me. This was year 5 for the plants. But if I was going to transplant it into the ground I'd do it in late fall after it goes dormant rather than in the early spring. I never grow horseradish but don't know of any reason why it can't be grown in containers assuming the containers are large enough. Dave

Good point zeedman. There are many great past discussions about horseradish here that address this question. When Don asked this question last year I think the consensus then was Fall harvesting is far superior to any Spring harvesting. Dave https://www.gardenweb.com/gardenweb/query/harvest-horseradish/topic=cornucop

Olychick, with cream and w/o is how I serve it with ham, sliced, and on sandwiches, as well as beef. I prefer mine with a bit of cream as well. I misunderstood the offerings at T-day this year with friends, and thought someone said there was horseradish (they served ham and turkey). So I asked where it was located and was told in the fridge and to help myself, but couldn't find a spare spoon so I just up-ended the jar. Got horseradish 'juice' only. Not tasty!