How to grow Globe Artichoke

Where to plant

Artichokes grow in most well-drained soils and need full sun. They have a taproot, so deep, loose ground helps. Plants grow 4 to 5 feet tall and more than 3 feet across, so give them plenty of room.

Artichokes crop best in cool, mild weather. Hot weather toughens the bud scales and cuts yields. The plant is perennial in USDA zone 7 and warmer, but in cold regions it is grown as an annual.

• Coastal California: the best climate in the country. Plants grown from crowns or divisions crop for four to five years.
• Hot inland California and the low desert: UC Master Gardeners suggest growing annual varieties such as 'Imperial Star' or 'Emerald', planted in July in the inland valleys or September in the low desert, for buds between January and April.
• The Northeast, Midwest, Mountain West, Northern Plains, Pacific Northwest and Alaska: grow it as an annual. Start seed indoors 6 to 12 weeks before the last frost and make sure the seedlings get a spell of cool weather before planting out.
• Florida, the Gulf South and Texas: grow it as a cool-season annual planted in winter, so it buds before summer heat.

Choosing a variety

How to plant

1. For annual growing, sow seed indoors 6 to 12 weeks before the last spring frost. Bottom heat of 70 to 80°F speeds germination. Grow seedlings at about 75°F by day and 65°F by night, and avoid temperatures above 80°F.
2. Make sure young plants get enough cold to set buds. Most varieties need about 500 hours between 35 and 50°F; Imperial Star needs about half that. Plant out early in spring so they get it naturally, protecting them from frost, or keep potted seedlings in a refrigerator below 50°F for at least 3 weeks.
3. Space plants about 2 feet apart in rows at least 4 feet apart. Perennial plantings need more room.
4. In mild-winter areas you can also plant dormant crowns or rooted divisions from an established plant.

Watering and feeding

Artichokes need 1 to 2 inches of water a week and do not tolerate drought. Most roots are fairly shallow despite the taproot, so water often and mulch to keep the soil evenly moist and cool.

Feed according to a soil test, working a balanced fertilizer into the bed before planting, and side-dress with a nitrogen fertilizer a few inches from the stem as plants grow.

Pruning and care through the year

• Keep weeds down around young plants. Once they are large they shade out weeds themselves.
• Straw mulch keeps the soil cooler, which artichokes prefer. Black plastic warms the soil and can undo the effect of chilling.
• In mild areas, cut perennial plants back after harvest and mulch the crowns. Divide established clumps every few years.
• In California, never let artichokes flower and seed near wild land. Cultivated artichokes hybridize freely with artichoke thistle, which the California Invasive Plant Council rates as a moderate invasive plant.

Harvesting

Cut buds while they are firm and tight, before the bracts begin to open, leaving 2 to 3 inches of stem. Once the bracts loosen, eating quality falls fast.

Each stalk carries one large top bud and several smaller side buds lower down. The small buds are excellent for marinating or freezing and often have no choke. Wear gloves, as the plants are spiny and the sap is sticky. Buds keep 2 to 3 weeks in the refrigerator.

Growing in pots

Artichokes can be grown in a 5-gallon container or larger with a light potting mix. Keep pots in bright sun but avoid baking the roots, as hot soil works against budding; light-colored pots help. Potted plants may need water daily and feeding every week.