How to Grow Imperial Star Artichoke

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Imperial Star Artichoke

Cynara cardunculus var. scolymus

vegetable

Imperial Star is a high-yielding artichoke variety bred to produce large, tender flower buds in a single season from seed, making it ideal for home gardeners in cooler climates. This compact cultivar reaches 3-4 feet tall and is known for its exceptional productivity, often producing multiple heads per plant. It matures faster than traditional artichoke varieties, allowing northern gardeners to harvest before frost.

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Example Imperial Star Artichoke timeline · Pittsburgh, PA (Zone 6b)

Plant Imperial Star Artichoke
Around Apr 17

Near Pittsburgh's average last spring frost.
Tend & protect
Late spring–summer

Watering, feeding, and pest-watch reminders.
Harvest Imperial Star Artichoke
Around Jun 26

≈ 70 days after planting

Sample dates for Pittsburgh, PA. Sign up to get exact Imperial Star Artichoke dates for your own zip code.

Growing Conditions

☀️

Sun: Full sun, 6-8 hours daily; tolerates light afternoon shade in hot climates

💧

Water: Keep soil consistently moist but not waterlogged. Water deeply 1-2 times per week depending on rainfall and temperature. Mulch heavily to retain moisture and regulate soil temperature.

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Spacing: 36 inches

📅

Days to maturity: 70-100 days from transplant; 150-180 days from seed

🌱

Planting depth: Start seeds 1/4 inch deep indoors; transplant seedlings at 3-4 true leaves

Soil

Type: Well-draining loamy soil rich in organic matter

pH: 6.0-7.5

Amendments:

Compost well-rotted manure peat moss aged leaf mold

Growing Zones

Find your zone →

Thrives in zones 5-9; can succeed in zone 4 with protection. Also grows well in zones 3-4 when started indoors early.

3a 3b 4a 4b 5a 5b 6a 6b 7a 7b 8a 8b 9a 9b 10a

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Growth Stages

Seedling

3-4 weeks

Tiny plants with 2-4 true leaves, emerging 7-14 days after sowing under grow lights

Maintain consistent moisture and 70-75°F soil temperature. Provide bright light to prevent leggy growth. Start seeds indoors 8-10 weeks before last spring frost.

Vegetative Growth

4-6 weeks

Young plants developing 6-12 true leaves with deeply lobed, silvery-green foliage; reaching 6-12 inches tall

Transplant seedlings to larger pots at 3-4 true leaves. Harden off for 7-10 days before outdoor planting. Keep soil moist and provide consistent light. Maintain temperatures between 60-70°F.

Establishment

3-4 weeks after transplanting

Plants reaching 18-24 inches tall with robust, silvery-gray foliage and visible plant structure; roots establishing deeply in garden soil

Water deeply and consistently; apply 2-3 inches of mulch around base. Begin light feeding with balanced fertilizer every 2-3 weeks. Remove any damaged leaves. Monitor for pests.

Bud Development & Flowering

3-4 weeks from visible bud formation to mature harvest-ready buds

Large, tight, edible flower buds developing at terminal and axillary positions; buds are purple-tinted, 3-5 inches in diameter, with overlapping bracts

Maintain consistent watering to support bud development. Feed with high-potassium fertilizer to promote quality buds. Provide afternoon shade if temperatures exceed 90°F regularly. Harvest buds before they open.

Production & Harvest

4-8 weeks or until frost

Central terminal buds ready for harvest, followed by numerous secondary side shoots producing additional smaller buds; plant may continue producing until frost

Harvest main terminal buds when tight but before scales begin separating. Harvest side buds promptly to encourage further production. Continue watering and light fertilizing. Cut stems with 1-2 inches of stalk attached.

Companion Planting

Plan your garden →

Plant with:

Basil Parsley Thyme Onions Garlic Carrots Beets Lettuce Spinach Lavender

Avoid planting near:

Fennel Dill Cabbage Potato Kohlrabi

Common Pests

Remove infested buds immediately. Inspect buds before harvest. Use row covers on young plants. Bacillus thuringiensis (Bt) spray if severe.
Spray with strong water stream to dislodge. Apply neem oil or insecticidal soap. Encourage beneficial insects like ladybugs and lacewings.
Increase humidity by misting foliage. Spray with neem oil or miticide if severe. Ensure consistent watering to prevent plant stress.
Hand-pick early morning or use traps away from plants. Apply neem oil in evening. Encourage native parasitoid wasps.
and
Remove debris and mulch where they hide. Use copper tape barriers. Set beer traps. Apply food-grade diatomaceous earth around plants.

Uses

🍳

Fresh cooking & steaming

Culinary

Artichoke buds are prized for steaming, roasting, grilling, or boiling, served with butter, lemon, or aioli. The tender inner leaves and heart are particularly delicious. [source]

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Preserving & canning

Culinary

Artichoke buds can be pickled, marinated in oil, or canned for long-term storage. They're a staple in Mediterranean cuisine and professional food preservation. [source]

💊

Liver support & digestive health

Medicinal

Artichoke has been used traditionally to support liver function and digestive health. The extract contains compounds that may promote bile production and support cholesterol metabolism. [source]

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Ornamental garden feature

Household

Imperial Star's silvery foliage and striking purple buds make it a beautiful addition to flower or vegetable gardens. The plant is attractive enough for ornamental borders. [source]

🦋

Pollinator & beneficial insect support

Wildlife

If allowed to flower, artichokes provide abundant nectar and pollen for bees, butterflies, and beneficial insects. The dried flower heads support finches and other seed-eating birds. [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 main terminal buds when 3-5 inches in diameter and scales are tight and compact, before bracts begin separating (typically 70-100 days after transplanting). Cut buds with 1-2 inches of stem attached using a sharp knife. Secondary buds will develop and can be harvested for 4-8 weeks. Pick regularly to encourage continued production. Best flavor develops in cool weather; harvest before buds overmature or become tough. Peak season is late summer through fall.

Fun Facts

🌱 Imperial Star was specifically bred by UC Davis to be an annual artichoke variety that produces in a single season from seed, revolutionizing artichoke growing for home gardeners in cooler climates.
🌱 Artichoke buds are actually the immature flower heads; if left unharvested, they will open into spectacular purple-blue thistle-like flowers that are highly attractive to pollinators.
🌱 Artichokes are a member of the thistle family (Asteraceae) and are technically the edible flower bud and receptacle of a flowering plant, not a vegetable botanically speaking.

Gardening Terms

New to gardening? Learn about terms used in this guide:

Cultivar Full Sun Mulch Transplant True Leaves

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