Zone 5.
http://durgan.org/2009/From%20Previo...HTML/index.htm 18 September 2008 Globe Artichoke (Cynara scolymus)
I grew artichokes for about four years. They were placed in the garden in the Spring (June) from seedlings started in the Winter. They never over-wintered in Zone 5. Above is the best picture that I could find. A plant gets huge and needs a spacing of 2.5 feet from center to center.. They like warm weather for max production and a fair amount of Sun. They are basically a large thistle. They are basically perennials and produce in the second year, but mine produced well in the first year. Zone 5 is too cold and I never got nine to over-winter due to frost. One year a plant survived but it did not produce a head.
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