Problems Growing Artichoke Plants

Hardiness

• When given winter protection, artichokes are hardy in U.S. Department of Agriculture plant hardiness zones 6 through 9, and sometimes survive mild winters in zone 5. All these plant zones experience freezing temperatures, so gardeners need to protect the roots and crowns of these tender perennials during winter. Cut the artichoke plants down to 12 inches, then completely cover them with leaves or straw before freezing weather arrives. Remove the mulch when temperatures rise in the spring, but re-cover the plants if a late freeze is forecast.

Consistent Moisture

• Plant artichokes in well-drained soil, but give them frequent waterings for best production. Artichokes tolerate drought but flower bud production is diminished and quality is poor. For best results, mulch the plants to conserve soil moisture.

Frequent Division

• Artichoke plants live for as long as 15 years, but produce best when young. For that reason, divide the plants every three to four years. Remove and replant the offshoots that form around the base of the parent plant. Space artichokes 4 to 6 feet apart in rows 6 to 8 feet apart. (ref 1, 2, and 4 re plant life span)

Soil pH and Composition

• Heavy feeders, artichokes require well-drained soil that's rich and deep. Before planting, enrich the top 12 inches of soil with lots of organic material such as compost or manure, the test the pH. Artichokes grow best in soil with a pH of 6.5 to 8.0, so if your soil falls outside that range, consult your local extension service or garden center for soil amendment recommendations.

Diseases

• Artichokes are susceptible to several diseases, but two, curly dwarf virus and Botrytis blight, are most common. Symptoms of curly dwarf virus are small, misshapen buds, curling leaves and stunted plant growth. Remove infected plants from the garden to prevent the disease from spreading. Botrytis is a fungal disease most common in warm, wet weather. The brownish-gray mold attacks plant tissue that's been damaged by frost or insects. Botrytis fungus overwinters on decaying matter, so keep the garden clear of fallen leaves and other debris.

Insects

• Aphids and spider mites are often found on artichoke buds. Although large numbers of these insects may require a pesticide, most infestations are light enough to be washed off with a strong stream of water from the garden hose. In parts of California, the artichoke plume moth is a serious problem. The moth lays its eggs on the underside of leaves or right underneath the bud. The larvae tunnel into the plant tissue, ruining the buds and weakening the plant. Artichoke plume moth infestations require a stringent garden hygiene regimen and regular insecticide applications. Always ensure that all chemicals used on artichokes are approved for use on food crops.