Cynara scolymus (Compositae Family)
This cool-season perennial prized for its flavorful “hearts” is normally hardy to Zone 6 if well mulched, and occasionally Zone 5 during mild winters. Its bristly leaves also add a unique texture to flower gardens.
Growing information
- Propagate by seed, division or separation – Seed may not breed true.
- Germination temperature: 70 F to 80 F
- Days to emergence: 8 to 12
- Seed can be saved 6 years.
Plant root divisions (basal stem pieces with attached roots) after last frost, 2 to 3 feet apart in rows 2.5 to 3 feet apart.
Planting from seed not recommended because results are highly variable and usually inferior to parent plants. But if you do, start seeds about 8 to 12 weeks before last frost. Harden off in cold frame. Cold treatment of starts (keeping temperature between 35 F and 50 F for about 10 days) can induce flowering in first-year plants. Transplant outside after soil has reached 60 F.
Benefits from the use of a low-nitrogen fertilizer (high in phosphorus and potassium), which can be incorporated before planting.
Plants usually don’t flower the first year.
To increase chance of overwintering, head back to 12 inches and cover with leaves, covered with baskets or boxes, and heap more leaves over the top of the basket. Another alternative is to dig roots and store in a cold (but not freezing) room. Pot up about a month before transplanting out after last frost.
While individual plants may live up to 15 years or more, divide about every 3 years to keep planting productive.
Pests
Aphids – A hard stream of water can be used to remove aphids from plants. Wash off with water occasionally as needed early in the day. Check for evidence of natural enemies such as gray-brown or bloated parasitized aphids and the presence of alligator-like larvae of lady beetles and lacewings.
Varieties
Browse globe artichoke varieties at our Vegetable Varieties for Gardeners website.
Green Globe and Green Globe Improved are standard commercial varieties grown in milder climates than those found in most of New York.
Shorter season varieties that are more likely to flower and winter over in New York include:
Imperial Star – grows just 3 feet tall
Violetto – purplish buds
Grande Buerre – spineless heads, grows up to 9 feet tall
More information
Site Characteristics
Sunlight:
- full sun
Soil conditions:
- requires well-drained soil
Prefers deep, fertile, well-drained soils high in organic matter with a pH between 6.5 and 8.0. A heavy feeder that requires lots of moisture for maximum growth. It will survive drought, but not produce well.
Hardiness zones:
- 6 to 9
With protection, may survive mild winters in Zone 5. Can be grown as an ornamental annual in colder zones.
Plant Traits
Lifecycle: perennial
Perennial Zone 6 and warmer, but often grown as an annual in colder areas.
Ease-of-care: difficult
Height: 3 to 6 feet
Spread: 2 to 4 feet
Bloom time: mid-fall
Flower color: violet
Flower resembles a thistle.
Foliage color: light green
Foliage texture: medium
Shape:
- spreading mass
- upright
Shape in flower: flower stalks with flowers as globes
Most gardeners remove and eat flower head and bracts before they open.
Special Considerations
Tolerates:
- frost – Tolerates heavy frost, but heavy frost will damage flower stalks.
- salt
Special characteristics:
- not native to North America
Special uses:
- edible landscaping