Green Globe
Globe Artichoke in the US

Right, growing these from seed, it's a bit of a challenge, to be honest, but well worth it. You'll want to start them indoors, usually about 120 days before you hope to harvest, which is typically July to September. For folks in warmer zones like 9 and 10, that means starting as early as January or February, or even late fall. If you're in zones 5-7, think March or April, and for zones 3-4, May is your best bet. Sow seeds about an inch deep in individual pots, keeping them warm, around 65-70°F (18-21°C), on a windowsill or with a heat mat if you've got one. They need a good start.

Once your seedlings have a few true leaves and are looking sturdy, pot them on into larger pots if they're getting crowded. Before planting them out, harden them off properly for a week or two, you know, getting them used to the outdoors. Don't rush it; wait until all danger of the last frost has passed. Artichokes are big plants, so give them plenty of room, about 3 feet (90cm) apart. They like a sunny spot with good drainage.