What are the sun requirements for Allium cepa 'Superstar'?

Allium cepa 'Superstar' is Superstar onion, a biennial grown as an annual for bulb production, 18-24 inches (45-60 cm) tall and 4-6 inches (10-15 cm) wide. Globe-shaped bulbs 8-12 ounces (225-340 g) with golden-bronze papery skins and white flesh. A long-day storage onion: requires 14-16 hours of daylight for bulbing (latitudes above 36°N). F1 hybrid — seed does not produce true to type. Stores 8-10 months at 32-40°F (0-4°C). The thin neck dries quickly during curing. Blue-green hollow tubular foliage. In the amaryllis family (Amaryllidaceae). Moderately pungent raw, mellows when cooked. Start seed indoors 10-12 weeks before last frost. Harvest when 50-75% of tops have fallen and yellowed (110-120 days from transplant). Cure 2-4 weeks. All Allium contain thiosulfates: toxic to dogs, cats, and horses. Deer-resistant. Full sun. Annual. Growth rate is moderate.

Native Range

F1 hybrid cultivar. The species A. cepa is native to Central Asia.

Suggested Uses

Grown in vegetable gardens and containers of at least 3 gallons (11 L). Long-storing white onion (8-10 months). Long-day type. F1 hybrid. Toxic to pets. Deer-resistant. Annual.

How to Identify

Identified by globe-shaped bulbs with golden-bronze skins and white flesh on a plant with blue-green hollow tubular foliage. Long-day storage type. F1 hybrid. In Amaryllidaceae.

Appearance

Size & Dimensions

Height1'6" - 2'

Width/Spread4" - 6"

Reaches mature size in approximately 1 years

Colors

Flower Colors

Foliage Colors

Fall Foliage Colors

Bloom Information

Biennial: flowers in the second year if overwintered — white spherical umbels. Grown as an annual for bulb production. Cut flower scapes at the base if they appear.

Detailed Descriptions

Flower Description

White spherical umbels — only if allowed to bolt; undesirable

Foliage Description

Blue-green, hollow tubular; yellows at maturity

Growing Conditions

Sun Requirements

Full Sun

Requires 6-12 hours of direct sunlight daily

• Full Sun: 6+ hours of direct sunlight

• Partial Shade: 3-6 hours of direct sunlight

• Full Shade: Less than 3 hours of direct sunlight

Soil Requirements

pH Range6.0 - 7.0(Neutral)

357912

Soil Types

loam

Drainagewell drained

Water & Climate

Water Needs

Medium

Frost Tolerance

hardy

Time to Maturity

110-120 days from transplant

Care & Maintenance

Care Guide

Full sun (6+ hours). Well-drained soil pH 6.0-7.0. Long-day onion — 14-16 hours daylight. Start seed 10-12 weeks indoors. Consistent moisture. Stores 8-10 months. F1 hybrid. All Allium toxic to pets. Deer-resistant. Annual.

Pruning

Cut flower scapes at the base if they appear. Do not cut green foliage. Harvest when 50-75% of tops have fallen. Trim tops to 1 inch (2.5 cm), roots to 0.25 inch (6 mm). Cure 2-4 weeks.