In warm climates, artichokes are an edible perennial or biennial, usually planted in the fall for a spring harvest, and grown as an annual in colder climates. Native to the Mediterranean, artichokes provide delicious, tender thistles for eating and are also a beautiful garden feature (zones 4 to 11).
Special features of artichokes
Green Globe Artichokes - Produce greenish globe-shaped fruits with a purplish base.
Imperial Star Artichokes - Rich flavored fruit; grow as an annual in zones 4-6 where you can't over-winter it, but as a perennial in zones 7 and above.
Choosing a site to grow artichokes
Plant in full sun in sandy, well-drained soil with a pH range of 6.5 to 8.0; Space your plants about 2 feet apart and water heavily.
Artichokes are best planted from bare-root stock or from divisions. They require regular water for an ample harvest, but if you are growing the plants just for looks and don't want the flower buds to eat, you can skimp on watering.
In cooler climates, start your plants in a cold frame five or six weeks before the last frost. After the danger of frost is past and soil temperatures exceed 60F, transplant your artichokes 2 feet apart in the garden. You can also start artichokes from seed indoors during the late winter about 10 weeks before the last frost.
How to harvest artichokes
Harvest buds when they're still tightly closed to ensure the best flavor and most tender leaves. You also have the option of leaving the buds on the plant to open and then harvesting them for use in flower arrangements.
Once the harvest is over, cut the plants back to 1 to 2 feet to try for a second harvest. New sprouts will form at the base of the plant and will mature by fall. At the end of the season, once the leaves begin to yellow, allow the plant to dry out. Cut back the foliage once it has dried and put down a layer of organic compost to enrich the soil for next year's crop.