Believe it or not, you can do succession planting with artichokes. You can sow the seeds and grow them at the same time but stagger the harvests with different types/varieties based on maturity dates.
Round / Globe: The buds on these plants are round. This is the most common type of artichoke if you are shopping for them in the Grocery store.
Oval / Elongated: The buds are longer and have an oval shape. This type typically matures later than globe artichokes.
Another way artichokes differ is by color (green or purple buds).
