Start artichoke seeds indoors in late winter, under bright florescent lights. Purple artichokes include ‘Violetta,’ an heirloom variety hardy to Zone 6, and the fast-maturing ‘Opera’ hybrid.
Green artichoke varieties include ‘Imperial Star,’ the best variety to handle as an annual, and ‘Green Globe,’ a heavy-bearing perennial hardy to Zone 7. The edible plant parts are the immature artichoke flower buds. Growing artichokes from seeds started in late winter will produce edible buds in midsummer and fall. In most areas, though, globe artichokes must be grown as annuals. Where winters are mild, you can grow globe artichokes as perennials, replacing plants every four years. Native to the mild climates of the Southern Mediterranean, globe artichokes ( Cynara scolymus) are half-hardy perennial thistles that are easily killed by temperatures below 20 degrees Fahrenheit. (For details on growing many other vegetables and fruits, visit our Crop at a Glance collection page.) Grow some in your garden to experience a real treat.