Globe artichoke is an heirloom vegetable grown for its tender, edible flower buds. With their large, silvery-green leaves and thick stems topped with pinecone-like flower buds, artichoke plants add a strong architectural element to vegetable garden plantings. Thomas Jefferson reportedly raised artichokes at Monticello, his Virginia home, as early as 1767. Today the majority of commercial artichoke production is along coastal sections of Central California, where the weather suits them perfectly. Here are some things you need to know about growing artichokes. Artichoke plants thrive best where mild winters and cool, foggy summers prevail. In such growing conditions, they are perennials, yielding harvests for up to 5 years. Where winters dish up only a few frosty nights, plants will sometimes overwinter when pruned and mulched (zones 8 and 9). In colder regions, you have to treat artichokes as annuals planted in spring. They are best planted in fall in the humid, subtropical, frost-free areas of zones 10 and 11.