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The Spokesman-Review Newspaper
Spokane, Washington  Est. May 19, 1883

In the Garden: Chill artichoke seedlings to fool them into producing

It’s possible to grow productive artichoke plants in Inland Northwest gardens. (SUSAN MULVIHILL/FOR THE SPOKESMAN-REVIEW)

If you love eating artichokes, you’ll be happy to hear that growing them in Inland Northwest gardens is doable. It just requires fooling them a bit.

For a long time, I’ve been envious of gardeners in USDA hardiness zones 7 to 11 because they can grow artichokes as perennials. That means they come back year after year. Those of us living in zones 5 and 6 have to grow them as annuals by starting the plants in the spring knowing they’ll die at the end of the growing season when it gets really cold.

There’s just one problem with growing them this way: Sometimes the plants might produce artichokes in that short amount of time, but, more often than not, they don’t produce any fruit.

On the bright side, artichoke plants are stunning in the landscape. The spiky leaves provide a nice contrast to other plants in the garden. But if you’d rather eat homegrown artichokes, there is a pretty simple way to get them to produce, a process called “vernalization.”

If you have started artichokes indoors or you intend to purchase plants from a nursery this spring, there is one extra step before transplanting them out into the garden.

In this region, it’s usually safe to plant warm-season crops outside around May 15. On about May 1, move your plants outdoors to expose them to chilly temperatures for two weeks, but don’t let them get frosted. You may have to cover them or move them to the garage some nights, but that’s OK. When May 15 rolls around, plant them in the garden.

Believe it or not, this step “fools” the seedlings into thinking they have been through a winter. They react to this by producing artichokes in the first year.

Next year, if you plan to grow artichokes from seeds, there is an extra step you can take to fool the seeds. Two weeks before you’d ordinarily start them indoors, refrigerate them inside a small plastic bag of lightly moistened peat moss or seed-starting mix. After that, start the seeds indoors just like you normally would.

When May 1 rolls around, expose the seedlings to two weeks of cool outdoor temperatures. These two steps should ensure a nice harvest in the summer.

Here is what I did this year:

I put my artichoke seeds into the refrigerator on Feb. 4. Two weeks later, I planted them indoors under a grow light. Once the seedlings were growing well, I moved them into 1-quart containers and have been feeding them with a liquid nitrogen fertilizer to promote leafy growth.

At the end of April, I will move the seedlings outdoors for two weeks to chill them. I always keep a close eye on the weather forecasts to make sure they won’t get exposed to a killing frost.

Since artichoke plants grow quite large, I recommend spacing them 3 feet apart. And remember, they look great in the landscape, so if you don’t have a spot for them in your vegetable garden, why not plant them in a flower bed instead?

The only insect pest that has ever bothered my plants is the occasional stinkbug. The easiest way to deal with them is by picking them off and dropping them into a container of soapy water.

Over the years, the artichoke varieties I’ve grown are Green Globe, Imperial Star and Violetta di Romagna. This year, I’m trying Tavor, a new open-pollinated, organic variety known for its vigor and ease of growing.

To learn more about growing artichokes, watch this week’s “Everyone Can Grow a Garden” video at youtube.com/c/susansinthegarden.

Contact Susan Mulvihill at susan@susansinthegarden.com.