Granex Yellow

Onion

Zone 5b Save Garden

🌱 100d to harvest Bulbing

Sunlit and sweet, Granex Yellow forms large, globe-flat bulbs with a mellow, honeyed bite that feels tender rather than sharp. Th…

Crop Dates

Milestone	Date
Start Indoors	Mar 23rd
Last Frost	May 4th
Transplant / Sow Outdoors	Apr 27th
Harvest Begins	Aug 5th
Harvest Ends	Oct 5th

Crop Details

Trait	Value
Days to Maturity	100
Sun Requirements	Full Sun
Growth Habit	Bulbing
Support Needed	None
Planting Depth	Normal
Germination Temp (°F)	70
Min Soil Temp (°F)	45
Min Night Temp (°F)	28
Harden Off (days)	7

Recommended Companions

Sunshine Cherry Tomato

Frequently Asked Questions

What pest or disease most commonly affects Allium cepa (Granex Yellow onion), and what should I do first?

Onion fly and thrips are common pests, and they often show up as wilting tips, silvery streaking, or larvae around the bulb neck. Start by removing and destroying any onions with soft, foul-smelling bases (a sign of bacterial rot) and check plants weekly for early thrips damage. Use insect netting over newly planted seedlings and apply an insecticidal soap for thrips when populations are low; keep the bed free of weeds that host pests.

How often should I water Allium cepa during the main growing phase?

During the main bulb-forming period (roughly mid-season after plants are well established), keep the soil evenly moist with about 1 inch of water per week, split into 1–2 waterings if it’s hot. Let the top few centimeters of soil dry slightly between waterings so bulbs don’t stay waterlogged, but don’t allow the bed to dry out for long stretches because onion bulbs can stall or split. Once tops begin to yellow and fall over near maturity, reduce watering to help curing and prevent rot.

How can I tell when Granex Yellow onions are ready to harvest?

Harvest when about half to two-thirds of the plants have fallen over and the necks are drying and tightening, typically around 100 days from planting. Lift one or two bulbs to confirm—skins should be papery and the bulb should feel firm with no soft spots. Harvest on a dry day to reduce skin damage, then cure the onions in a warm, airy place out of direct sun until the necks are fully dry.

Sunlit and sweet, Granex Yellow forms large, globe-flat bulbs with a mellow, honeyed bite that feels tender rather than sharp. The flesh is crisp and juicy with a fine-grained texture, ideal for showcasing in bold, golden-forward preparations—roasted for caramel depth, sliced for fresh salads, or simmered into silky sauces and savory relishes. A short-day favorite for home gardeners seeking dependable size and a bright, market-ready look at harvest.

Sowing Tips

Transplant Conditions

Wait until soil reaches 45°F and nights stay above 28°F before moving outdoors. Harden off for 7 days first.

Expert Note

For sweet, mild short-day onions, keep soil consistently moist early and avoid nitrogen excess so bulbs size up instead of staying leafy.