How to Grow Artichokes

A strong presence in the garden, artichoke (Cynara scolymus), hardy in U.S. Department of Agriculture plant hardiness zones 8 through 11, has bold, gray-green, deeply cut leaves and edible flower buds that resemble a tight green pine cone. If not harvested, the buds develop into large, purple, thistle-like flowers. Plants grow 2 to 5 feet tall and 3 to 5 feet wide, and the buds harvested from one plant can feed three or four people during the spring harvest.

Artichoke is a fast-growing plant that needs rich but loose and well-draining soil and ample room. Amend the soil before planting by spreading 5 inches of compost on top of an 8-inch-wide and -deep trench and digging it in, creating a slightly raised planting bed. Space artichokes 4 feet apart in mild climates, 2 to 3 feet apart in colder areas where they are treated as annuals.

Although artichokes need ample water during their growing season and need to be kept moist, they don't tolerate wet roots. Give the roots good drainage by planting on a mound or in rows with irrigation furrows at the sides. Water the plants at least weekly, supplying 1 to 2 inches of water each week. Water more frequently in sandy soils or warmer weather. Conserve water by mulching artichokes with a 4-inch layer of organic matter such as straw, dry grass clippings, aged manure, or a combination of these ingredients.

Growing best in areas with cool summers, mild winters and high humidity, artichokes need full sun in such areas. In hotter, drier areas, plant them in full sun or partial shade. In USDA zones 8 and 9, where occasional winter freezes occur, protect the artichokes with layers of mulch and by pruning the plant back to about 12 inches high. Tie the cut stems together over the top of the plant before it's mulched, and put an overturned bushel basket on top of the mulched plant to overwinter it.

With such vigorous growth, artichokes need regular fertilizing during their growing season. Every four weeks, beginning four weeks after setting out the plants, apply 2 teaspoons of 12-0-0 fertilizer. Spread it evenly along the sides of the plant and water it into the soil. Continue fertilizing until the plant is done producing flower buds. In mild winter climates with hot, arid summers, the growing season is from fall through winter and spring. In cold-winter climates, artichokes grow from spring into fall. Under optimum conditions such as those present in coastal California, artichokes produce both a spring and a fall crop.