
Allium cepa 'Yellow Granex'
Yellow Granex Onion
F1 hybrid cultivar; the species A. cepa is native to Central Asia
Overview
Allium cepa 'Yellow Granex' is Yellow Granex onion (Vidalia-type), a biennial grown as an annual for bulb production, 12-18 inches (30-45 cm) tall and 4-6 inches (10-15 cm) wide. Flattened globe-shaped bulbs 3-4 inches (7-10 cm) diameter with golden-brown papery skins and white to pale yellow flesh. A sweet onion: reduced sulfur compounds — mild enough to eat raw. Blue-green hollow tubular foliage. In the amaryllis family (Amaryllidaceae). A short-day onion: bulbs at 10-12 hours of daylight (latitudes below 35°N). The Yellow Granex is the Vidalia-type parent cultivar — true Vidalia onions are Granex-type cultivars grown in a 20-county region of southeastern Georgia where low-sulfur soil contributes to the mild flavor. F1 hybrid — seed does not produce true to type. Stores only 1-2 months — the shortest storage of any onion type due to high water content and thin skins. Use fresh. Start seed indoors 10-12 weeks before last frost, or fall-plant in zones 7-10. Harvest when 50-75% of tops have fallen (100-110 days from transplant). 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 (Iran, Afghanistan, Pakistan).Suggested Uses
Grown in vegetable gardens and containers of at least 5 gallons (19 L). Short-day sweet onion — Vidalia-type parent. Stores only 1-2 months — use fresh. F1 hybrid. Toxic to pets. Deer-resistant. Annual.How to Identify
Appearance
Size & Dimensions
Height1' - 1'6"
Width/Spread4" - 6"
Reaches mature size in approximately 1 years
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; undesirableFoliage Description
Blue-green, hollow tubular; yellows at maturityGrowing 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
Care & Maintenance
Care Guide
Full sun (6+ hours). Well-drained soil pH 6.0-7.0. Short-day onion — 10-12 hours daylight (latitudes below 35 degrees N). Fall-plant in zones 7-10. Consistent moisture during bulb swelling. Stores only 1-2 months — use fresh. 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 during growth. Harvest when 50-75% of tops have fallen. Trim tops to 1 inch (2.5 cm). Cure 1-2 weeks only (thin skins).Maintenance Level
lowContainer Growing
✓ Suitable for container growing
Minimum container size: 5 gallons
⚠️ Toxicity Warning
Toxic to petsPlanting Guide
Planting Methods & Timing
Planting Method
both
Indoor Start
10 weeks before last frost
Direct Sow Timing
Early spring when soil can be worked; fall planting in zones 7-10
Days to Maturity
100–110 days
Plant Spacing
4 inches