What are the sun requirements for Allium cepa 'Super Star'?

Allium cepa 'Super Star' requires full sun.

Annuals

Allium cepa 'Super Star'

Super Star Onion

UnknownAsia

At a Glance

Typeannual

Habitupright

Foliagedeciduous

Height18-24 inches

Width4-6 inches

Maturity0.25 years

Key Features

Deer Resistant

Container Friendly

Maintenancemoderate

Overview

Allium cepa 'Super Star' is a premium storage onion cultivar renowned for its exceptional uniformity and extended keeping quality. This robust annual vegetable produces large, perfectly globe-shaped bulbs measuring 3-4 inches in diameter, enclosed in golden-bronze papery outer scales that provide excellent protection during storage. The crisp, white interior flesh is arranged in well-defined concentric rings, offering a balanced pungency that makes it ideal for both fresh culinary use and long-term storage applications. The plant develops distinctive hollow, cylindrical leaves that emerge directly from the bulb base, reaching 18-24 inches in height with an attractive blue-green coloration enhanced by a natural waxy coating. This waxy surface helps reduce moisture loss and provides some protection against environmental stress. The foliage maintains its upright habit throughout the growing season, with leaves tapering to pointed tips. When allowed to continue into a second growing season, Allium cepa 'Super Star' will produce tall, sturdy flowering stems topped with spherical umbels of small white flowers, though commercial cultivation focuses on first-year bulb development for optimal storage quality.

Native Range

Allium cepa originates from the mountainous regions of southwestern and central Asia, with its primary center of diversity located in modern-day Afghanistan, Iran, Pakistan, and surrounding areas. Wild populations of the species can still be found growing naturally in rocky, well-drained soils at elevations between 3,000-6,000 feet in these regions. The species has been cultivated for over 5,000 years and spread globally through ancient trade routes, becoming one of humanity's most important and widely grown vegetable crops.

Suggested Uses

Premium storage onion ideal for home gardens, market gardens, and commercial production where long-term storage is desired. Excellent for fresh culinary use in cooking, suitable for dehydrating, and exceptional for root cellar or cool storage lasting 8-10 months when properly cured.

How to Identify

Allium cepa 'Super Star' can be readily identified by its characteristic hollow, tubular blue-green leaves that feel waxy to the touch and emit the unmistakable sharp onion aroma when bruised or cut. The bulbs are notably uniform in their globe shape, distinguishing them from flattened storage onions or elongated varieties, and develop distinctive golden-bronze outer scales that are papery and thin. Unlike garlic, the leaves are completely round in cross-section rather than flat, and unlike shallots, the plants produce single large bulbs rather than clusters of smaller bulbs. The leaves emerge directly from the bulb top without any visible stem, creating a fountain-like growth pattern that is characteristic of true onions.

Appearance

Size & Dimensions

Height1'6" - 2'

Width/Spread4" - 6"

Reaches mature size in approximately 0.25 years

Colors

Flower Colors

white

Foliage Colors

blue

green

Fall Foliage Colors

yellow

Bloom Information

Bloom Period

SpringSummer

Late spring to early summer (if allowed to continue to second year)

Detailed Descriptions

Flower Description

Small white flowers in spherical clusters

Foliage Description

Blue-green with natural waxy coating

Growing Conditions

Sun Requirements

Full Sun

• 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

Drainage

well drained

Water & Climate

Water Needs

moderate to high during bulb development, reduced near harvest

Frost Tolerance

hardy

Time to Maturity

100-120 days from transplant

Care & Maintenance

Care Guide

Allium cepa 'Super Star' requires consistent soil moisture throughout the growing season, particularly during active leaf growth and bulb development phases. Provide 1-1.5 inches of water weekly through irrigation or rainfall, but reduce watering frequency as bulbs approach maturity to promote proper curing. Apply a balanced fertilizer (10-10-10) at planting time, then side-dress with nitrogen-rich fertilizer when plants reach 6 inches tall to encourage vigorous foliage growth. Discontinue nitrogen applications once bulbs begin to swell noticeably, as excess nitrogen can delay maturation and reduce storage quality. Maintain excellent weed control throughout the season, as onions have shallow root systems and compete poorly with weeds for nutrients and moisture. Hill soil gently around bulbs if they begin to push above ground level, but avoid covering the neck area completely.

Pruning

Allium cepa 'Super Star' requires minimal pruning during the active growing season to achieve optimal bulb development. Remove any flower stalks immediately upon appearance to redirect the plant's energy into bulb formation rather than seed production. Avoid cutting or damaging the foliage throughout the season, as the leaves are essential for photosynthesis and proper bulb development. Allow the foliage to remain intact until it naturally begins to yellow and topple over, typically when 50-75% of the tops have fallen. At this stage, cease watering and allow the remaining foliage to dry down completely before harvest, which promotes proper skin formation and enhances storage quality.

Maintenance Level

moderate

Container Growing

✓ Suitable for container growing

⚠️ Toxicity Warning

Allium cepa 'Super Star' is safe for human consumption when used fresh or cooked in normal culinary quantities. However, onions are highly toxic to dogs, cats, and other companion animals, causing hemolytic anemia, gastrointestinal upset, and potentially life-threatening complications. All parts of the plant contain organosulfur compounds that damage red blood cells in animals, with toxicity persisting even when the onions are cooked, dried, or processed. Pet owners should exercise extreme caution to prevent animal access to both fresh plants and kitchen scraps containing onion.

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 date

Days to Maturity

100–120 days

Plant Spacing

4 inches

Companion Planting

Good Companions

carrots

tomatoes

peppers

brassicas

lettuce

parsley

Avoid Planting With

beans

peas

asparagus

sage