Growing Artichokes - March 30, 2011
Jeff Schalau, Associate Agent, Agriculture & Natural Resources
University of Arizona Cooperative Extension, Yavapai County
While many gardeners would consider the globe artichoke to be more appropriate for milder, coastal climates, I know several gardeners that have successfully grown artichokes in Yavapai County. These perennial plants can be grown for both for edible flower buds and showy garden flowers. Historically, artichokes originated in southern Europe where they were cultivated since Roman times. They were brought to California by Spanish explorers. Artichokes are grown for the soft fleshy receptacle and thickened bases of the bracts of the flower heads.
The artichoke is a cool weather perennial thistle plant in the Asteraceae (sunflower) family. Artichoke plants have long, arching leaves that are silver-green in color. A mature plant reaches a height of 4 feet with a width of 6 feet. Edible globe artichokes are harvested in the bud stage before the flower opens. The open flowers are purple in color and will grow up to a diameter of 7 inches if not harvested. The yield from the three or four plants should be quite enough for a small family's enjoyment. And once established an artichoke plant can remain productive for four to seven years.
Globe artichokes prefer full sun and deep, fertile, well-drained soils high in organic matter. In limy areas, you may also add soil sulfur to temporarily lower alkalinity (pH). After the soil has been amended with compost, phosphorus fertilizer should also be placed about 8-10 inches deep to make it readily available to plant roots. Artichokes also require lots of moisture for maximum growth. They can survive drought, but will not produce well without consistent soil moisture.
Artichoke plants are generally large and spiny. Most people purchase root crowns which will usually produce a crop of artichoke buds the first year after planting. The crowns are planted in late spring. Artichokes can be grown from seed. However, some varieties have greater variability in production and quality when grown from seed. Crowns should be planted three to five feet apart.
Established artichoke plants produce several stalks and each stalk bears several flowers. For edible buds, harvest them before they open. In our climate, pay careful attention to ripening flower buds and harvest them before they start to open or become tough. If left to flower, the plant will produce a large purple thistle that can be dried and used in arrangements. If you harvest all the flowering heads, artichokes may send up a second crop of flowers in the fall.
In areas that receive freezing temperatures, artichoke plants should be headed back to 12 inches and covered with deep mulch of straw or leaves prior to winter. Uncover in late spring and inspect the crowns for signs of life. If freeze damage occurs, remove the affected material the following spring or replant with new crowns. If plants have survived, then remember to lightly side dress a balanced fertilizer (i.e. 10-10-10) during the growing season. Artichoke plants should be divided every 3-5 years. Prior to replanting, the soil should be prepared again as described above.
The variety ‘Green Globe’ is commonly grown in California but may not be the best suited variety for Arizona’s summer heat. The variety ‘Imperial Star’ was developed by California Cooperative Extension and has shown broad climatic adaptability. It is currently being grown in southern California coastal regions, and in desert areas in California and Arizona. I would recommend trying Imperial Star.
Aphids are often attracted to globe artichoke plants and can be easily managed by spraying with a hard stream of water from the hose. Wash off with water occasionally as needed early in the day. Check for evidence of natural enemies such as gray-brown or bloated parasitized aphids and the presence of alligator-like larvae of lady beetles and lacewings.
Globe artichokes can be prepared by boiling or steaming for 25 to 45 minutes. To test for doneness, pull off a petal (flower bract) and sample for tenderness and flavor. I hope this has inspired you to consider growing a few artichoke plants in your garden or landscape!
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Last Updated: March 24, 2011
Content Questions/CMarch 24, 2011g.arizona.edu