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

Allium cepa 'Granex' requires full sun.

How much water does Allium cepa 'Granex' need?

Allium cepa 'Granex' has moderate water needs.

Annuals

Allium cepa

Granex Onion

UnknownAsia

At a Glance

Typeannual

Habitupright

Foliagedeciduous

Height18-24 inches

Width4-6 inches

Maturity0.33 years

Key Features

Container Friendly

Maintenancelow

Overview

Allium cepa 'Granex' is a sweet, short-day onion cultivar prized for its mild flavor and excellent storage qualities. This variety produces large, globe-shaped bulbs with golden-yellow papery outer scales and crisp, white to pale yellow flesh beneath. The plants develop typical onion foliage consisting of hollow, cylindrical leaves that emerge from the bulb in a fan-like arrangement, reaching 18-24 inches in height. Allium cepa 'Granex' is distinguished from other onion varieties by its particularly sweet taste, low sulfur content, and adaptability to shorter daylight periods. The bulbs can reach 3-4 inches in diameter when fully mature and have a flattened globe shape. This cultivar is known for its excellent keeping quality and resistance to bolting, making it ideal for both fresh consumption and storage.

Native Range

Allium cepa originates from Central Asia, particularly the mountainous regions of Afghanistan, Iran, and neighboring areas. The species has been cultivated for over 5,000 years and spread throughout the world, with 'Granex' being a modern cultivar developed in the United States.

Suggested Uses

Allium cepa 'Granex' is excellent for fresh eating, cooking, and storage. Use in salads, sandwiches, and cooked dishes where a mild onion flavor is desired. Suitable for container gardening and vegetable gardens. The sweet flavor makes it particularly good for caramelizing and in dishes where raw onion is used.

How to Identify

Allium cepa 'Granex' can be identified by its characteristic hollow, tubular leaves that are blue-green in color and its developing bulb at the base. The bulb has golden-yellow outer papery scales and a flattened globe shape. When mature, the foliage begins to yellow and fall over, indicating harvest time. The plant may produce a tall flower stalk with white, globe-shaped umbel flowers if allowed to bolt.

Appearance

Size & Dimensions

Height1'6" - 2'

Width/Spread4" - 6"

Reaches mature size in approximately 0.33 years

Colors

Flower Colors

white

Foliage Colors

blue

green

Fall Foliage Colors

yellow

Bloom Information

Bloom Period

SummerFall

late summer if allowed to bolt

Detailed Descriptions

Flower Description

white

Foliage Description

blue-green

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

Drainage

well drained

Water & Climate

Water Needs

moderate

Time to Maturity

3-4 months

Care & Maintenance

Care Guide

Allium cepa 'Granex' requires consistent moisture during the growing season, particularly during bulb development. Water regularly but avoid overwatering, which can lead to rot. Apply a balanced fertilizer at planting and side-dress with nitrogen when plants are 6 inches tall. Cease fertilizing 6 weeks before harvest to promote proper bulb maturation. Keep the area weed-free as onions compete poorly with weeds.

Pruning

Allium cepa 'Granex' requires minimal pruning. Remove any flower stalks that appear to direct energy into bulb development rather than seed production. Do not cut back the foliage until it naturally yellows and begins to fall over, as the leaves continue to photosynthesize and feed the developing bulb throughout the growing season.

Maintenance Level

low

Container Growing

✓ Suitable for container growing

⚠️ Toxicity Warning

Allium cepa 'Granex' is generally safe for human consumption when properly prepared. However, all parts of the plant are toxic to dogs, cats, and other pets, potentially causing anemia and digestive upset. Keep pets away from onion plants and properly dispose of onion scraps.

Planting Guide

Planting Methods & Timing

Planting Method

both

Indoor Start

10 weeks before last frost

Direct Sow Timing

early spring, 4-6 weeks before last frost

Days to Maturity

90–120 days

Plant Spacing

4 inches

Companion Planting

Good Companions

carrots

lettuce

tomatoes

brassicas

peppers

Avoid Planting With

beans

peas

asparagus