Growing Artichokes Outside of California
Question. Greetings Mike! I am a lover of all things Mediterranean and have mastered the art of growing thyme, rosemary, and garlic. Now I really want to try artichokes, but wonder if it's even possible to grow them in the North. What do you think?
---Kerry in Southern Coastal Delaware
Mike: I went to THE website (that's what I call your site) and was shocked; for the first time, your alphabetical index failed me. You have no information on artichokes! From the little I could find elsewhere on the web, it seems like it's possible to raise artichokes down here in the South, but there was conflicting information on what varieties would be best to try; and not a lot of info at all on how to care for the plants. Do you have any advice/expertise to share? I'm sick of paying $3-4 to get a 'choke fix'! Thanks!
---Trent in Canton, GA
Answer. Thank you for your (unfounded) faith in my ability to do Wikipedia impressions, Trent—but if I had already covered everything in those archives, I'd have no new topics left to write about! (Not that I'm looking forward to stumbling around this one, mind you…)
Requests for information about growing artichokes outside of their typical range come in fairly frequently, and I have looked into the topic previously—always coming to the conclusions that 1) there's probably a darn good reason virtually 100% of the U.S. crop is grown in a single county in Central California; 2) if you live in that part of California you probably already know how to do it; and 3) I should stop looking for trouble.
But you can only dodge a good topic for so long (13 years in this case; not bad!), and I was able to find some seemingly good advice on Northern artichoke growing in a 1993 ORGANIC GARDENING article (back when I was the magazine's editor in chief) and the 'Kitchen Garden A to Z' coffee table book (Abrams; sadly now out of print) I wrote some years back.
Although artichokes are technically perennial plants that typically produce edible leaves and hearts beginning in their second year, these non-rogue members of the otherwise-weedy thistle family can theoretically be grown as a one-year crop by gardeners who are willing to utilize a fair amount of trickery and deception—two essential attributes for those who choose to pursue horticulture—to mimic the artichoke's ideal growing conditions: An area with mild, non-freezing winters and cool summers (otherwise known as Monterey County, California).
Everyone agrees that you begin with seed. Back in the 90s we recommended the variety "Green Globe Improved" for non-California adventures. Since then, "Imperial Star" has become the variety of choice, with the Wikipedia entry on artichokes noting that an improved variety known as "Northern Star" is even more cold hardy than 'Imperial', and could be the new standard, especially the further North you want to try this. But everyone seems to have a slightly different technique for germinating the seeds and coaxing the plants along. Some sources say to simply pot up the seeds in soil-free mix about two months before your last average frost date, and move the seedlings into bigger pots after about five weeks, always keeping the temperature around 60° during the day and 50° at night. Then transplant them outdoors when there's no longer ANY chance of frost but when you can be assured they'll get at least two weeks of 'vernalization'—temperatures that hover right around 50°—to induce budding. If they freeze, you won't get buds; if the temps climb above a torrid 70° or so you won't get buds. (Isn't this fun? Central CA is looking better all the time!)
David Hill, a Connecticut Extension Agent we interviewed back in the OG article, related that he preferred to pre-chill his seeds, packing them in moist sphagnum moss in an unsealed plastic bag in the fridge for the entire month of February, spritzing the moss with water whenever it started to get dry. The seeds apparently like it cold, as he reported that his typically sprouted in the fridge. In March, he says to pot the seedlings up in soil free mix and give them good light, but keep them cool until it's safe to plant them outside—when, again, they need that extended period of 50° weather to set their all-important buds.
No matter how you start them, plant the seedlings at the correct magical time in your richest soil, about two feet apart. Use row covers to protect the plants on nights that dip towards frost in early Spring. Then mulch them with at least two inches of well-shredded leaves to keep the roots cool as Spring progresses, have a fast hand with the water, spray the plants with cold water if temps get even slightly hot, light a candle to the Blessed Mother, and you might get a nice edible crop by July—after which this game will be called due to excessive heat.
Down South? I first warn our Georgia listener that my main reference for your region, the excellent "Southern Living Garden Book", avoids any mention of artichokes in its 700 + oversized pages. As omens go, that's like a raven landing on your potting bench, looking at your pack of artichoke seeds and saying, "don't do that".
But I did find other references that suggest Southerners with very mild winters try planting the seeds directly in the soil in the fall after all threat of HOT weather has passed. Mulch them heavily, remove the mulch temporarily in the Spring, thin the plants to two feet apart, replace the mulch, keep the plants very well watered, and harvest when the weather starts to get into the 70s.
Here's what Wikipedia has to say about the edible thistles.
And here's the official website of the California grower's association, with lots of fun facts about 'chokes.