Growing horseradish (and containing it)

Horseradish (*Armoracia rusticana*) is one of those plants that rewards good planning at the outset -- specifically, planning for containment. The plant produces its best roots in zones 3-7, where cold winters kill back top growth and allow the root system to concentrate its energy. It spreads.

Horseradish (Armoracia rusticana) is one of those plants that rewards good planning at the outset — specifically, planning for containment. The plant produces its best roots in zones 3-7, where cold winters kill back top growth and allow the root system to concentrate its energy. It spreads aggressively via root fragments. Any piece of root left in the soil becomes a new plant. Once established in a site, it is extraordinarily difficult to remove completely.

I don't grow horseradish at my Long Island plot. The combination of containment demands and my sandy soil would make it a reasonable candidate, but I haven't committed the bed space. This guide is sourced from Extension publications.

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Identification

Per Missouri Botanical Garden, Armoracia rusticana is a large-leafed perennial reaching 24-36 inches in height. The basal leaves are large, oblong, and toothed with long petioles. In summer it produces small white flowers on tall branching stems. The taproot is thick, fleshy, and branched, with pungent white flesh.

The pungency comes from allyl isothiocyanate, released when root cells are damaged — the same compound responsible for the heat in wasabi and mustard.