Green gardening: Growing rhubarb

Rhubarb is classified as a vegetable but its red, tart stalks are traditionally used as a fruit in pies, cobblers, jams, and jellies, or simply stewed and served as a compote. Rhubarb needs minimum care and produces for many years.

Rhubarb grows well in almost any type of soil, but it is a heavy feeder and should not be planted in poor soil unless you are able to add copious quantities of organic material and fertilizer. Rhubarb plants need well-drained, fertile soil, and the ground has to be worked quite deeply. But rather than having to dig a row or trench, you need only make a hole for planting each crown.

Rhubarb is a long-lived perennial plant, and its cultivation is similar in many respects to that of another prized perennial vegetable, asparagus. Like asparagus, rhubarb is planted in beds that require a lot of preparation, but once the plants are established, they need a minimum of care and will produce for many years. Like asparagus, rhubarb needs a dormant period and grows best in areas where winters are cold enough to freeze the ground to a depth of at least five to eight centimetres (two to three inches).

Because rhubarb is a perennial plant, which inhabits the same piece of ground for many years, it should be given an isolated spot in your vegetable garden — in a corner, for example, or along one side — where it will not interfere with, or be damaged by, your work on annual crops.

• Canada Red and Valentine are standard red-stemmed rhubarb varieties.
• Victoria has green, rather than red, stalks.
• For areas where the winters are relatively mild, Cherry Red is recommended.

Rhubarb is seldom started from seeds. Instead, it is propagated by planting crowns — root divisions that carry the buds from which new plants will grow. Rhubarb crowns can be ordered from seed catalogue companies, or you can buy the crowns from your local nursery or garden centre.

• Dig the holes 60 centimetres (25 inches) deep and 60 centimetres (25 inches) wide, and space them about 90 centimetres (35 inches) apart in all directions. Then fill the bottom of each hole with a 15-centimetre (six-inch) layer of compost or rotted manure.
• Mix the soil you have dug up with an equal amount of compost or rotted manure. Fill the hole with the enriched soil mixture to a depth of about 30 centimetres (12 inches).
• In early spring place one rhubarb crown in each hole so that the top, where the plant buds are located, sits eight to 10 centimetres (three to four inches) below the soil surface.
• Tamp the soil firmly around the roots, and fill each hole with the compost and topsoil mixture until level with the surrounding soil.
• When the first growth appears — and every succeeding spring as well — spread a one-centimetre (half inch) layer of compost around the shoots, and scratch it into the soil with a hand cultivator.
• Maintain a permanent mulch around each plant to help keep the soil moist and to prevent winter frost from setting in too hard around the roots. Remove the mulch before fertilizing, and afterward push it back in place.

• Harvest rhubarb by holding the stalk near the base and twisting it off.
• Do not eat the leaves; they are mildly poisonous.