GardenLine | Vegetables | Horseradish

Soil Preparation

A deeply worked, moist loam with a high organic matter content is the ideal soil for horseradish. Soils suitable for rhubarb and asparagus will suffice for horseradish.

Planting

In the fall, cut off the lateral roots which have developed on the main tap root. Tie the lateral roots into a bundle and bury them in the soil at least 7.5 cm (3 in.) below the soil surface; a mulch applied over these roots will help prevent winter injury. A more reliable method is to store the root bundles in a root cellar. Early in spring, plant these root-cuttings in a vertical position, with the larger end upward. Cover them with 2.5 to 5 cm (1 to 2 in.) of soil. The thicker lateral roots are more desirable because they will yield a larger tap root in the fall. The within-row spacing for the plants is 46 cm (18 in.). One row of horseradish is usually sufficient.

Cultural Requirements

If the soil has been well prepared with rotted manure (5 to 7.5 cm/2 to 3 in. incorporated in to the soil), commercial fertilizer will not be required. Adequate moisture will result in optimum yields, but the plants will produce edible roots with minimal watering. Excessively good growing conditions will enhance the spread of this plant.

Harvesting

Most of the root growth occurs in late fall. Therefore, delay harvesting until late September. At this time carefully dig around the plant. There will be many lateral roots attached to the tap root. Try to dig up as many lateral roots as possible with the tap root. The tap roots can be stored in a cold room like potatoes. The lateral roots are removed and discarded, or used for root-cuttings for next year's crop.

It is unlikely that you will succeed in removing all of the lateral roots from the ground during harvesting. If they do not freeze over the winter,the roots left in the ground will produce new plants the next spring. In this way, the horseradish plant can become a hard-to-eradicate weed - unless it is kept confined by deep cultivation.

JERUSALEM ARTICHOKES

This perennial vegetable produces a small tuber similar to a potato. It is a member of the sunflower family - a close relative to the wild sunflower that grows in many parts of Saskatchewan. It not related, however, to the artichoke (Globe artichoke) found in food stores. The mature Jerusalem artichoke may reach a height of 1.8 m (6 ft), producing a sunflower-like, yellow flower-head late in the summer.

Jerusalem artichokes can be boiled or baked in their jackets like potatoes; they can also be served sliced raw in salads

Soil Preparation

Any soil that grows good potato crops will also grow good Jerusalem artichokes. A deeply worked soil which has had an adequate amount of well-rotted manure added is ideal. Incorporate 5 to 7.5 cm (2 to 3 in.) of the manure into the soil. Heavy (clay) soils are not the most suitable but the addition of organic matter will greatly improve such soils for growing artichokes.

Planting

The small, rough tubers similar to potato tubers are planted whole or cut. Leave at least one eye per piece. Planting is done in early spring. Tubers are set about 7.5 cm (3 in.) below ground level in rows 91 to 120 cm (3 to 4 ft) apart. The in-row spacing should be about 61 cm (2 ft). The plants require this much space because, as noted earlier, they can attain a height of 1.8 m (6 ft).

Cultural Requirements

The watering and fertilizing requirements for horseradish also apply to Jerusalem artichoke.

Harvesting Most of the tuber growth occurs in late fall. Therefore, as with horseradish, delay harvesting until late September. Start digging about 1 m (3 ft) from the base of the plant. Dig carefully to avoid damaging the tubers. Damaged tubers will soon spoil in storage. Cold, moist storage conditions are a necessity, as Jerusalem artichoke tubers dry out very readily. Small tubers can be left in the garden over winter. If they do not freeze, they will produce new plants in the spring. Mulching is recommended in exposed areas to prevent winter damage.

Like horseradish, the Jerusalem artichoke can become a troublesome weed. Some tubers are likely to escape harvesting, and growth can get out of control if it is not confined by deep cultivation.

Don Dabbs and Grant Wood

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Sustainable horticultural information, offered free of charge to the public with the support of the University of Saskatchewan Extension Division, the Department of Plant Sciences and the Provincial Government.