Yellow Granex

Onion

Zone 6b Save Garden

🌱 90d to harvest Bulbing

Golden warmth spills from every Yellow Granex bulb—sweet, mellow flavor with a gentle bite that lingers like sun on skin. At matu…

Crop Dates

Milestone	Date
Start Indoors	Feb 14th
Last Frost	Apr 25th
Transplant / Sow Outdoors	Apr 18th
Harvest Begins	Jul 17th
Harvest Ends	Oct 16th

Crop Details

Trait	Value
Days to Maturity	90
Sun Requirements	Full Sun
Growth Habit	Bulbing
Support Needed	None
Planting Depth	Normal
Germination Temp (°F)	70
Min Soil Temp (°F)	40
Min Night Temp (°F)	35
Harden Off (days)	7

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Frequently Asked Questions

What pest or disease commonly affects Allium cepa (yellow onions), and how can I stop it?

Onion thrips can cause silvery streaking and distorted onion leaves, especially in warm, dry spells. Check plants weekly and spray insecticidal soap or spinosad according to label directions; keep weeds down because they host thrips. If you see soft, rotting bulbs or purple-gray mold at the neck, remove affected plants immediately and improve airflow—onions in wet, crowded beds develop neck rot and other fungal issues.

How often should I water Allium cepa during the main growing phase (bulb formation)?

During bulb formation, keep soil consistently evenly moist but not soggy—about 1 inch of water per week, adjusting for heat and rainfall. Water deeply to reach the root zone, then let the top 1–2 inches of soil dry slightly before watering again. When about 10–20% of the tops begin to fall over near the end of the 90-day cycle, reduce watering to help bulbs cure and prevent watery rot.

How do I know when Allium cepa (yellow Granex-style onions) are ready to harvest?

Harvest when plants reach roughly 90 days from planting and most tops have turned yellow and started to fall over, with dry, tight necks. Gently lift one or two bulbs to confirm the skin is papery and bulbs are fully sized. Leave onions in place to cure for a short period with good airflow, then cure longer indoors out of direct sun if weather is humid.

Golden warmth spills from every Yellow Granex bulb—sweet, mellow flavor with a gentle bite that lingers like sun on skin. At maturity, the bulbs form broad, flattened globes with crisp, papery outer layers and a dense, juicy interior that stays tender and slice-ready. Grow Yellow Granex for reliable harvests around 90 days, ideal for fresh use, roasting, and caramelizing into rich, golden sauces.

Sowing Tips

Transplant Conditions

Wait until soil reaches 40°F and nights stay above 35°F before moving outdoors. Harden off for 7 days first.

Expert Note

For short-day sweet onions, start transplants early and keep them growing steadily—avoid drought stress to prevent premature bolting and small bulbs.