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Vegetable Garden Care: Root Vegetables

Red beets; photo Courtesy of Flickr cc/Alice Henneman
Red beets; photo Courtesy of Flickr cc/Alice Henneman


Horseradish (Armoracia rusticana) is in the Brassicaceae family. It is related to cabbage and kale. Sixty percent of the world’s supply of horseradish is grown by German immigrants in Illinois on the banks of the Mississippi river. The soil in this area is ideal for horseradish: fertile soil that is high in potash. The area has long summers and cold winters.

It is one of the easiest things to grow in the garden. Its foliage looks like a hybrid between sorrel and kale and the root (the edible part of the plant) is reminiscent of parsnip.


The best time to plant horseradish is in the spring. It will take full sun or part shade and tolerate basically any type of soil. In fact, it will be so comfortable growing in your garden it may be hard to get rid of it. It is best to put it in the corner of your garden where it is out of the way and make sure you place it where you want to keep it.


You don’t have to pay much attention to your horseradish but it will be happier if you water it during dry spells and give it a layer of mulch to suppress weeds and retain moisture. Make sure that you do not fertilize it with a high nitrogen fertilizer that will push leaf growth at the expense of the roots.


Harvesting can happen late in the fall or sometime in the following year. Horseradish is a perennial herb and once the root is harvested the crown of the plant and a small portion of the root can be successfully replanted.

Horseradish gets its smell and intense flavor from volatile oils that are released when it is grated. Harvest the root and chop off what you intend to use for several weeks. If you tear up while chopping onions, prepare for a flood while grating the horseradish root! The easiest way to prepare it is pare the outer layer with a potato peeler. Chop into cubes and place in a blender. Add some water and vinegar to the mix. The vinegar in the mix stabilizes the flavor of the horseradish. If you would like a milder preparation add the vinegar sooner than later. If you like it hot, then grind for about 3 minutes before adding. It will store in the refrigerator for a month and for much longer in the freezer.

Jerusalem Artichokes

Jerusalem artichoke (Helianthus tuberosus), a native North American relative of the sunflower, may have been labeled Jerusalem since it fed the pilgrims and was part of the ‘new Jerusalem’. The moniker artichoke comes from its taste. Jerusalem artichokes (or sunchokes) love the sun. They are hardy perennials from zone 2 to 9 and fit into the category of ‘once you have it you can’t get rid of it’. They can grow up to 12 feet tall and are covered with small yellow sunflowers. The edible part of the plant is a tuber which looks like a cross between a fingerling potato and ginger root.


Plant the tubers in the spring, setting them 3 to 5 inches deep and 18 inches apart. Amend the soil with compost or aged manure for the planting year and then top dress in subsequent years. Cover the bed with a good layer of straw mulch to suppress weeds and retain moisture. Because of their magnificent height, it is best to place them on the north side of your vegetable garden where they will not shade out other plants. Due to their tenacious growth habit many people plant them in a bed of their own.


The tubers are dug in the fall. It is best to wait until after they are cut back by the frost since the flavor improves with the cold. The easiest way to harvest is to dig up what you need with a spading fork and keep the bed mulched so you can dig as needed throughout the season. There will always be a number of strays or escapees that then provide your crop for the following year.

Jerusalem artichokes contain no starch. They are ideal for diabetics and people who are watching their calories. The tubers can be steamed, stir-fried, roasted, pureed, pickled and even eaten raw.


There are two major types of garlic: hardneck and softneck. Softneck garlic varieties (Allium sativum, Sativum group) include silverskin and artichoke garlic. These are the supermarket varieties that lack a woody stem and store well (from 6 months to 1 year).

Hardneck garlic varieties (Allium sativum, Ophioscordon group) have woody stems, tend to be cold hardy, but don’t store as well (generally only up to 6 months). Chefs claim the flavor of hardnecks is unrivaled. This group includes purple-striped, porcelain and rocambole types.

When starting out, remember to buy your garlic bulbs from a grower. Some options are Johnny’s Select Seeds, Seeds of Change, and Seed Saver’s Exchange. It is not recommended that you use garlic purchased at the supermarket as they are often treated to prevent sprouting.


While much of a garden is planned and planted in the spring, garlic is best planted as a fall crop, treated like any other hardy bulb. Planting in the fall enables the plant to develop a good root system but no top growth so that in the spring, once the temperatures warm up, it is ready to go. In the New York area garlic is generally planted in October and November. Take a nice fat bulb and split it apart into individual cloves, using only the larger cloves in the garden. (A larger bulb has more food storage capacity, so you get a larger, healthier plant.)

Garlic likes full sun and good drainage, and generally benefits from the addition of compost, cow manure or leaf mold. Heavy soil should be turned: Loose soil is important for good bulb formation. Plant the cloves 1 to 2 inches deep and 4 to 6 inches apart.

Vegetable experts advise that garlic should not be planted where any member from the cabbage family was growing; apparently this can inhibit the garlic’s growth up to 60 percent. Other sources tell you not to plant garlic in the same location where any member of the onion family had been growing.


In this area and in cooler regions it is a good idea to mulch the garlic with 2 to 3 inches of straw once the ground is frozen to prevent frost heaves or damage during the winter months. Remove the straw in the spring and top dress with compost. Garlic has a talent for adapting to local conditions. Try a number of varieties and see which ones work best for you.


Beets deserve a place in everyone’s vegetable garden. Between the beet greens and the beet root, they are an excellent source of vitamins A, C, and several Bs (B1, B2, B6, and folic acid), calcium, manganese, potassium, iron and fiber. Beets are easy to grow and their foliage is so beautiful that beets have as much a place in an ornamental garden as in an edible garden.   


For tasty and tender beets, it is important to start with good soil. Amend the soil with plenty of compost. If your soil pH is on the acidic side, it is worth adding lime. Beets prefer a soil pH of around 6.5. If you are not sure about your soil pH, take a soil test and send it to your co-operative extension.

Take your garden fork and turn the planting area to a depth of 8 to 10 inches. This will not only help incorporate the organic matter, but it will also relieve any soil compaction and make it possible for the root vegetable to grow unhindered.

There are a number of seasons in which to sow your beets. You can sow them in the spring beginning 2 to 3 weeks before the last frost date in your area. Successive planting (where you stagger your crop) is recommended. Sow them at 2 to 3 week intervals all the way until the end of June. You can also sow beets in the beginning of August for a late-season harvest. This will be a fast crop for the fall that can be harvested when the beets are still young.

Seeds sometimes germinate inconsistently, so sow 1 inch apart and then thin once the leaves are 1 to 2 inches tall. It is best to thin the plants by cutting off the tops rather than pulling them out (so you don’t disturb the soil). If you are growing beets for the greens, you do not have to thin. Grow until 6 inches tall and harvest. If you are growing them for the roots, thin 4 to 6 inches apart.


Beets are incredibly tender when they are harvested young. Greens take approximately 35 days to grow while the roots take 50 to 60 days to develop.

You will lose many of the nutrients if you peel the beets before you cook them, causing them to bleed. Cook them unpeeled with a little bit of the tops still intact and then peel and slice them. There are many ways to enjoy beet roots. You can pickle them, boil them or roast them. Jamie Oliver has a wonderful recipe in which he slices them into chunks and adds some thyme, olive oil, and garlic before wrapping them in tinfoil and tossing them in the oven.


Catalogs offer a wonderful selection to choose from: ‘Detroit Dark Red’ is a classic, ‘Burpee’s Golden’ is a sweet yellow selection that doesn’t bleed and is perfect for salads, ‘Chioggia’ is an Italian beet that has concentric rings of white and red (that unfortunately disappear when cooked), and ‘Bull’s Blood’ has deep red foliage.

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