Think artichokes only grow in California? Think again. These big, silvery plants are a showstopper in the garden, and with the right timing you can harvest buds in a single season, even where winters are cold. In this guide, you'll learn how to start artichokes from seed, the simple trick that gets them to bud the first year, and how to know when to pick.
Why grow artichokes?
An artichoke is actually the unopened flower bud of a giant thistle relative. Homegrown buds are tender and nutty, and each plant can give you several of them. The plants themselves are beautiful, too, growing 3 to 4 feet tall and wide with deeply cut, silver-green leaves. If you leave a bud on the plant, it opens into a huge purple flower that bees love.
Can you grow artichokes in a cold climate?
Green Globe and similar artichokes are perennials in mild areas, roughly zones 7 to 10. In colder areas, including here in Minnesota, zone 5a, you can grow them as annuals. The key is a process called vernalization.
Artichokes normally bud in their second year after going through a cool winter. You can fool them into budding the first year by giving young plants a few weeks of cool temperatures in spring. That's what makes a one-season harvest possible in the North.
When should you start artichoke seeds?
Start seeds indoors about 8 to 12 weeks before your last spring frost. In zone 5a, that's usually February or early March.
- Sow: Plant seeds about 1/4 inch deep in individual 3 to 4 inch pots of seed-starting mix, like our Elite Seed and Clone Soil.
- Keep warm: Seeds germinate best at about 70 to 80°F and usually sprout in 1 to 3 weeks.
- Give strong light: Grow seedlings under lights for 14 to 16 hours a day so they stay sturdy.
- Pot up: Move them to larger pots if roots fill their containers. Artichokes grow big fast.
How do you vernalize artichokes?
Once seedlings are about 6 to 8 weeks old with several true leaves, they need roughly 10 days to 2 weeks of temperatures between about 45 and 50°F. There are two easy ways to do this:
- Outdoors: Set plants out in a sheltered spot during cool spring weather, bringing them in or covering them if a hard frost (below about 28°F) threatens.
- Cool room: Keep them in an unheated garage or porch with light, as long as it stays above freezing.
A greenhouse cover is handy here for protecting young plants outdoors on chilly nights.
Planting and caring for artichokes
- Sun: Give them full sun, at least 6 to 8 hours a day.
- Space: Plant about 3 to 4 feet apart. They really do get that big.
- Soil: Rich, well-drained soil with plenty of compost. Artichokes are heavy feeders but hate soggy roots.
- Water: Keep soil evenly moist, about an inch or more a week. Drought stress makes buds tough.
- Feed: Side-dress with compost or a balanced fertilizer about a month after transplanting.
- Mulch: A layer of straw or shredded leaves keeps moisture steady and roots cool.
When are artichokes ready to harvest?
First-year plants usually start budding in mid-to-late summer, roughly 85 to 100 days after transplanting. Harvest buds when they're firm and tightly closed, before the scales begin to spread open.
- Start with the main bud: The central bud on top of the stalk is the biggest. Cut it with 1 to 2 inches of stem.
- Keep picking: Smaller side buds form after you cut the main one. They're perfect for roasting whole.
- Leave a few: Let one or two buds bloom if you'd like a gorgeous purple flower for the bees.
Can you overwinter artichokes?
In zones 7 and warmer, cut plants back in fall and cover the crowns with a thick layer of mulch, and they'll return next spring. In colder zones, it's simplest to treat them as annuals and start fresh from seed each year.
Give these garden giants a try
Artichokes take a bit of planning, but there's something special about cutting your own buds from a plant you started in February. Plan your seed-starting now and you'll be ready when the season comes. Free shipping kicks in on seed orders over $35, so it's easy to stock up on seed-starting supplies at the same time.
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