Answer: Dig the roots when they are large enough to suit you. You can dig them right up until the frozen ground stops you! Peel the root and grate it by hand or in a food processor. You can add salt and vinegar to taste. It keeps in the 'fridge for up to 6 weeks. You can also store the roots in sand or sawdust in a cool spot. By the way, did you know you can use the young leaves of this plant in your salad?
Remember to save a few of the smaller roots for next year's planting. Horseradish can also be quite invasive, so it's probably a good idea to plant them in a bottomless pail that you sink into the ground.
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