How to Grow Artichoke Green Globe Imperial Star
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Artichoke Green Globe Imperial Star
Cynara cardunculus var. scolymus
vegetableImperial Star is an improved cultivar of the classic Green Globe artichoke, bred for earlier maturity and the ability to produce in both cool and warm climates. This perennial is grown as an annual or short-lived perennial for its large, thistle-like flower buds that are harvested and eaten as a gourmet vegetable. The plant produces tall, dramatic silvery-green foliage and can reach 3-4 feet in height.
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Example Artichoke Green Globe Imperial Star timeline · Pittsburgh, PA (Zone 6b)
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Plant Artichoke Green Globe Imperial Star
Around Apr 17Near Pittsburgh's average last spring frost.
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Tend & protect
Late spring–summerWatering, feeding, and pest-watch reminders.
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Harvest Artichoke Green Globe Imperial Star
Around Jun 26≈ 70 days after planting
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Growing Conditions
Soil
Growing Zones
Find your zone →Thrives in zones 8-11; can be grown as annual in zones 6-7 with winter protection
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Seedling
3-4 weeksSmall plants with 2-3 true leaves emerge; foliage is soft green. Plants are delicate and vulnerable to damping off.
Start seeds indoors 6-8 weeks before last frost. Maintain consistent moisture but avoid waterlogging. Provide bright light and good air circulation. Thin seedlings to one per cell.
Vegetative Growth
4-6 weeksRapid leaf expansion with distinctive silvery-green, deeply lobed, thistle-like foliage. Plant develops thick, sturdy stems and reaches 2-3 feet tall.
Harden off transplants gradually. Plant outdoors after last frost date when soil is warm (50°F+). Apply mulch around base. Begin regular fertilizing with balanced fertilizer every 2-3 weeks. Ensure consistent watering.
Bud Formation
3-4 weeksFlower buds begin developing at the tips of main and lateral stems. Buds are tight, compact, and grayish-green with overlapping bracts.
Continue regular watering and fertilizing, switching to higher potassium formulation. Monitor for pests and diseases. Remove any damaged or yellowing lower leaves. Thin lateral buds on main stems to encourage larger primary buds.
Bud Maturation & Harvest
4-8 weeks (harvest window)Buds reach full size (4-5 inches diameter for primary buds) with plump, tightly closed bracts. Color intensifies to deep gray-green. Buds may begin to open if left too long.
Harvest when buds are firm and bracts are tight; before they begin to flower. Cut with 2-3 inches of stem attached. Secondary buds continue developing on lateral shoots after primary bud harvest. Extended harvest period with proper management.
Post-Harvest Management
Ongoing (8+ weeks)Plant continues producing smaller secondary buds on lateral branches if managed as perennial. Foliage may decline with heat stress in summer.
Continue watering and fertilizing for secondary bud production. In warm climates, provide afternoon shade during intense heat. Cut back spent shoots. In zones 8-9, mulch heavily in winter to protect crown. Replace plant after 2-3 seasons or when production declines.
Companion Planting
Plan your garden →Plant with:
Avoid planting near:
Common Pests
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Monitor for small larvae in flower buds. Remove and destroy affected buds. Use pheromone traps to track populations. Apply spinosad or Bt if populations are high.
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Spray with strong water stream to dislodge. Use neem oil or insecticidal soap. Encourage natural predators like ladybugs and lacewings. Plant companion flowers to attract beneficials.
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Increase humidity and water frequency. Spray with neem oil or sulfur. Use predatory mites (Phytoseiulus persimilis). Avoid excessive nitrogen fertilizer which promotes susceptibility.
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Inspect regularly and remove by hand. Spray with dormant oil in winter. Use neem oil during growing season. Prune heavily infested branches.
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Remove infested buds promptly. Use pheromone traps. Apply kaolin clay to plants for deterrent effect. Maintain good sanitation of fallen plant material.
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Ensure good air circulation. Avoid overhead watering. Apply sulfur or neem oil spray at first sign of infection. Remove affected leaves. Water only at soil level.
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Improve air circulation and reduce humidity. Remove affected plant parts immediately. Avoid overhead watering. Apply copper fungicide if needed. Space plants adequately.
Uses
Gourmet vegetable preparation
CulinaryArtichoke buds are steamed, boiled, grilled, or roasted as a delicacy. The tender inner heart is particularly prized. Commonly served with lemon butter, garlic aioli, or hollandaise sauce. [source]
Mediterranean and Italian cuisine
CulinaryA staple in Mediterranean cooking, used fresh in salads, in pasta dishes, as pizza toppings, or marinated and preserved. The hearts are popular in antipasto preparations. [source]
Liver and digestive health support
MedicinalArtichoke contains cynarin and other compounds believed to support liver function and bile production. Traditionally used to aid digestion and reduce cholesterol. Often consumed as tea or extract. [source]
Ornamental garden feature
HouseholdThe silvery-green, deeply lobed foliage and tall growth habit make artichoke an attractive addition to perennial borders and Mediterranean-style gardens. Dramatic architectural form. [source]
Pollinator attraction
WildlifeIf flowers are allowed to bloom (left unharvested), the purple-blue thistle flowers are highly attractive to bees, butterflies, and other pollinators, providing late-season nectar. [source]
This is not medical advice. LizPlants is not a medical resource. Always consult a qualified healthcare professional before using plants medicinally.
Harvest Tips
Harvest primary buds when they are 3-5 inches in diameter, firm, and before bracts begin to separate or flower opens. Cut with a sharp knife, leaving 2-3 inches of stem attached for easier cooking. Harvest in early morning when buds are crisp. Once primary bud is harvested, secondary buds develop on lateral branches below; continue harvesting these smaller buds for 4-8 weeks. In cool climates, plants may produce throughout fall. Store unwashed buds in refrigerator (32-40°F) for up to 2 weeks, or blanch and freeze for longer storage.
Fun Facts
- 🌱 Imperial Star was specifically bred by UC Davis to mature 30-40 days earlier than standard Green Globe and to reliably produce in its first year from seed, making it ideal for home gardeners and commercial growers outside traditional artichoke regions.
- 🌱 Artichokes are technically the unopened flower buds of a thistle plant; if left unharvested, the buds open into striking 2-3 inch purple-blue flowers that are edible and highly prized by pollinators.
- 🌱 California produces over 99% of the artichokes grown in the United States, with the bulk coming from Monterey County, but Imperial Star's improved adaptability has enabled successful cultivation in home gardens across zones 6-11.
Gardening Terms
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