On a visit to Wililamsburg a few years ago, I stopped at the colonial garden plot. There was a 8-foot tall (2.5 m) cardoon with intense blue flowers on the top, and large 1-foot long (30 cm) leaves. When my landscape architect friends offered a few cardoon plants to me last fall, I eagerly accepted and planted them in the south-facing side yard against the brick house. They stayed green all winter, began growing in March, and reached 6-foot (2 m) in height. Now they are blooming atop the artichoke bud.
The 4-inch (10 cm) spherical cardoon flowers look like a thistle on steroids - ten times as large and with an ice blue color. Cardoons are members of the artichoke family and are a type of thistle. I find them big attractions for pollinators like carousing bumble bees who spend the night on the flowers, and awake in morning sleepy and lethargic as hangover victims.
One source states "I've found that cardoons offer excellent habitat for Ladybugs to breed and multiply in, so our cardoon patch not only serves as a food crop, it's also an insectary that benefits the rest of our more common vegetable crops." I have seen ladybug nymphs on my cardoons this spring.
Native to the Mediterranean region, the stalks have been a food for centuries according to ancient Greek records, and were even cultivated by American colonists. Some sources claim they are an invasive species - so I guess they fit right in with my gardens. They are sold in a handful of farmer's markets today, and can be found in French, African, and especially Italian cuisine. Recipes for Cardoon Gratin, Sauteed Cardoon with Thyme and Pine Nuts, Cardoon-Pasta, Pureed Cardoon Soup, bechamels, and stews can be found on the internet. So can growing instructions.
I was intrigued enough to look into harvesting them for grilled pizza. The stalks (resembling celery) are blanched while growing for about two weeks before harvest - and they are harvested before they bloom. One method for blanching includes include wrapping the stems with straw and manure, which unfortunately (or fortunately) I don't have a lot of on hand. It is too late in the season to harvest my cardoons, but maybe next year.
For The Record:
Heavy clay soil with a few amendments
Full sun, normal water
Pests include leafhoppers, black aphids, spider mites
Blooming: pink cosmos, mexican zinnia, rudbeckia, cleome, echinacea,
lavender, cardoon, zinnia, platycodon, echinops, nicotiana, monarda, liatris
Harvested: 28 cherry tomatoes