Allium cepa 'Super Star', Super Star Onion

Allium cepa 'Super Star'

Super Star Onion

Cultivar of garden origin: 'Super Star' is an F1 hybrid white storage onion bred for long shelf life, golden-bronze papery skin, and the thin-neck character that supports the long storage; the species {Allium cepa} is native to Central Asia (Iran, Afghanistan, Pakistan) where the wild ancestor still grows in dry rocky habitats; the long-day photoperiod requirement (14-16 hours daylight for bulbing) restricts cultivation to latitudes above 36°N in North America, which covers the northern half of the United States and all of Canada

At a Glance

TypeAnnual
HabitUpright
FoliageDeciduous
Height18-24 inches (45-60 cm)
Width4-6 inches (10-15 cm)
Maturity1 years

Overview

Allium cepa 'Super Star' is Super Star onion, a biennial in the amaryllis family (Amaryllidaceae) grown as an annual for bulb production, reaching 18-24 inches (45-60 cm) tall with a 4-6 inch (10-15 cm) spread. The cultivar produces globe-shaped bulbs 3-4 inches (7-10 cm) in diameter with golden-bronze papery outer skins and white flesh. The bulbs hold storage quality 8-10 months at 32-40°F (0-4°C) and rank among the longer-storing white onion cultivars. Foliage is blue-green hollow tubular with a natural waxy coating. F1 hybrid — seed does not produce true to type. A long-day onion that requires 14-16 hours of daylight for bulbing, restricting cultivation to latitudes above 36°N. Moderately pungent raw, the flavor mellows when cooked. The thin neck dries quickly during curing — the thin-neck character is the key to long storage since thicker necks retain moisture and rot during storage. Start seed indoors 10-12 weeks before last frost. Harvest when 50-75% of tops have fallen and yellowed (100-120 days from transplant). Cure 2-4 weeks. All Allium contain thiosulfates that are toxic to dogs, cats, and horses. Onion maggot (Delia antiqua) and thrips are the primary pests. Deer-resistant. Full sun. Annual. Growth rate is moderate.

Native Range

F1 hybrid cultivar. The species Allium cepa is native to Central Asia (Iran, Afghanistan, Pakistan).

Suggested Uses

Grown in vegetable gardens and containers of at least 3 gallons (11 L). Long-storing white onion holding 8-10 months. Long-day type for latitudes above 36°N. F1 hybrid. Toxic to pets. Deer-resistant. Annual. Not suited to short-day southern latitudes (below 36°N) where the photoperiod does not trigger bulbing — Southern growers use short-day or day-neutral cultivars instead.

How to Identify

Identified by globe-shaped bulbs with golden-bronze papery skins and white flesh on a thin neck atop a plant with blue-green waxy hollow tubular foliage. The thin neck and the golden-bronze color separate Super Star from other long-day storage cultivars. 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 — small white flowers in spherical umbels. Grown as an annual for bulb production. Cut flower scapes at the base if any appear during the growing cycle to keep the plant's energy directed into bulb development.

Detailed Descriptions

Flower Description

Small white flowers carried in spherical umbels — only if plants overwinter and bolt; bolting is undesirable in a bulb crop and the harvest goal is to lift the bulbs before any flower stalks emerge

Foliage Description

Blue-green hollow tubular leaves with a natural waxy coating, 0.5-0.75 inch (12-18 mm) in diameter, yellowing at maturity as the bulb completes development

Growing Conditions

Sun Requirements

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
Drainagewell drained

Water & Climate

Water Needs

Medium

Frost Tolerance

hardy

Time to Maturity

100-120 days from transplant

Care & Maintenance

Care Guide

Full sun (6+ hours per day). Well-drained fertile soil at pH 6.0-7.0. Long-day onion requiring 14-16 hours of daylight for bulbing. Start seed indoors 10-12 weeks before last frost. Consistent moisture during bulb swelling, then reduce watering as tops yellow and the plant approaches maturity. Bulbs hold storage quality 8-10 months at 32-40°F (0-4°C). F1 hybrid. All Allium are toxic to pets. Deer-resistant. Annual.

Pruning

Cut flower scapes at the base if any appear during the growing cycle. Do not cut the green foliage during growth since photosynthesis from the leaves drives bulb expansion. Harvest when 50-75% of tops have fallen and yellowed. Trim tops to 1 inch (2.5 cm) and roots to 0.25 inch (6 mm). Cure 2-4 weeks in a warm dry well-ventilated location before storage.

Maintenance Level

low

Container Growing

✓ Suitable for container growing

Minimum container size: 3 gallons

⚠️ Toxicity Warning

Toxic to pets

Planting Guide

Planting Methods & Timing

Planting Method

both

Indoor Start

10 weeks before last frost

Direct Sow Timing

Early spring 2-4 weeks before last frost

Days to Maturity

100–120 days

Plant Spacing

4 inches

Companion Planting