Early green annual for summer harvests.
A green artichoke specifically bred for annual production, Imperial Star will produce well-developed artichokes the first year from seed. Plants become 1 1/2-3′ tall and have an open growth habit. Each typically produces 1-2 primary buds, which average 3-4" in diameter, and 5-7 smaller secondary buds. Perennial in Zone 7 and warmer; otherwise treat as an annual. Avg. 10,500 seeds/lb. Packet: 25 seeds.
SCIENTIFIC NAME: Cynara spp.
CULTURE: Artichokes and cardoon require very fertile, well-drained soils with a pH of 6.5-7.0. Sow artichokes indoors 8-12 weeks before last spring frost date. Cardoon is more vigorous and can be started later, 6-8 weeks prior to last frost date. Plant 2-3 seeds per cell in plug trays or individual containers 1/4" deep. Germinate at 70-80°F (21-26°C). As soon as seedlings can be handled, transplant to 4" pots or 1½" cell-type containers and grow at 60-70°F (15-21°C) day and 50-60°F (10-15°C) night. Transplant 6- to 12-week-old plants to the field 2-3′ apart in rows 4-6′ apart.
IMPORTANT COLD TREATMENT (VERNALIZATION): Time transplanting so plants receive 10 days of 45-50°F (7.2-10°C) temperatures to induce budding. Protect from frost.
HARVEST: Clip mature buds midsummer to midfall, depending on location.
MILD AREAS: Where winter low is above 14°F (-10°C), sow seeds in fall, harvest in spring.
SEED SPECS: SEEDS/LB.: Avg. 11,500.
BLANCHING: Gather stalks in late summer or early fall, tie upright with twine, and wrap with black plastic or black and white newspaper to exclude sunlight. Blanch for 3-4 weeks during the cooler weather of early fall.
HARVEST: Harvest after blanching, cutting at the base of the stalks to keep intact.
SEED SPECS: SEEDS/LB.: Avg. 11,600.
DAYS TO MATURITY: From transplant.
PACKET: 25 seeds, unless otherwise noted.