About 90 to 100 days after transplanting, the plants send up one or two flower stalks with heads. Artichokes grown as annuals usually produce around six heads, while those overwintered can produce up to 12.
Watch the heads carefully as they begin to develop; they'll become tough and woody if left too long. The head at the tip of the flower stalk is usually the first to mature. Harvest when it's about the size of a large lemon and the scales are still closed. Cut about 2.5 centimetres below the head. This will encourage others to form.
Store unwashed artichokes in a sealed plastic bag in the refrigerator, sprinkling them with a bit of water to prevent dehydration. Store for up to two weeks.
Art Form Farieties
‘Imperial Star' Bred specifically for growing from seed as an annual, it's the best variety for gardeners with short growing seasons; produces six to eight plump heads in 85 to 90 days from transplanting. Withstands temperature extremes fairly well; has thornless leaves.
‘Green Globe' First variety widely grown as an annual. Yields good-quality, tasty heads but takes a week or so longer to mature than ‘Imperial Star'.
‘Violetto' Attractive Italian variety with very ornamental purple heads. Takes several weeks longer to mature than ‘Green Globe', so unlikely to produce chokes in short-season areas. It's worth experimenting with a few plants started 10 weeks early indoors. Cooking turns the heads green.
The Cook's Garden: ‘Imperial Star', ‘Violetto'.
Pinetree Garden Seeds: ‘Green Globe Improved', ‘Imperial Star', ‘Violetto'.
Richters Herbs: ‘Green Globe'.
The Territorial Seed Company: ‘Green Globe', ‘Violetto'.
West Coast Seeds Ltd.: ‘Green Globe', ‘Violetto'.