How to grow Rhubarb

Where to plant

Choose a sunny spot with fertile, loamy, well-drained soil and plenty of organic matter, and clear out perennial weeds first. Rhubarb rots in wet soil, so avoid low spots. As it stays for years, put it at the side or end of the vegetable garden, or use its bold leaves in a perennial border.

Rhubarb needs cold winters to rest. Varieties such as MacDonald, Crimson Red, Victoria and Canada Red grow well in zones 4 to 7. Cool nights also bring out the red stalk color; in the South, warm nights leave stalks greener and plants weaker.

• Northeast, Midwest, Northern Plains, Mountain West, the Pacific Northwest and Alaska: plant dormant crowns in early spring as soon as the soil can be worked. It is a long-lived perennial here.
• Mid-Atlantic, Mid-South and Southern Plains: plant in early spring; give afternoon shade and mulch in hot summers.
• Northern California: plant dormant crowns in late winter or early spring.
• Southern California: mild winters give thinner stalks and short-lived plants. Choose Victoria, plant in fall or late winter, and give afternoon shade inland.
• North Florida, the Gulf South and Texas: grow it as a winter annual. Plant in fall (crowns, or seed started indoors in August in Texas), pick from about March, and pull it when the heat arrives.
• Central and South Florida, the Desert Southwest and Hawaii: not suited.

Choosing a variety

Rhubarb is usually bought as crowns or divisions, which come true to type. Plants from seed vary in color and size. MacDonald, Crimson Red, Canada Red, Valentine and Victoria are common choices. Some, such as Valentine, send up flower stalks more readily than others. Victoria is the variety most often grown from seed in warm areas.

How to plant

1. Loosen the soil about 10 inches deep and mix in 3 to 4 inches of compost or well-rotted manure.
2. Plant crowns as soon as you get them so they do not dry out; soak dry divisions in water for a few hours or overnight first.
3. Space crowns about 3 feet apart and cover the buds with no more than 1 to 2 inches of soil.
4. Water in well and mulch, keeping mulch off the crown buds.

Watering and feeding

Keep the soil evenly moist through spring and summer, especially in dry spells, but never waterlogged, which causes crown and root rot.

Rhubarb is a heavy feeder. Top-dress with compost or manure in late fall or early spring, and feed again after the harvest ends to rebuild the crown.

Pruning and care through the year

• Cut flower stalks off at the base as soon as they appear; they take energy from the crown.
• After the last harvest, let the leaves grow on until frost kills them, as they feed the crown for next year.
• In cold areas, once the tops have died and the ground is frozen, a 2 to 3 inch layer of straw helps protect the crown.
• Divide crowns every 5 to 10 years, or when stalks become thin and crowded. Dig in early spring and replant pieces with at least one bud.

Harvesting

Do not harvest in the first year, and take only a few stalks in the second. From the third year, harvest from spring into early summer, about eight weeks in total. Grip each stalk near the base and pull it with a slight twist rather than cutting, then trim off the leaf.

Never take more than one third to one half of the stalks at a time, and stop when new stalks come up thin, a sign the crown is running low. Fresh stalks keep two to four weeks in the fridge.

Using it

Stew rhubarb with sugar, or bake it in pies, crumbles and cakes. It pairs well with strawberries and ginger. Only eat the stalks: the leaf blades contain large amounts of oxalic acid and must not be eaten.

Propagation and saving seed

Rhubarb is propagated by dividing the crown in early spring. Each piece needs at least one strong bud and some root. Seed is possible but slow, and the plants do not come true to color and size.