Gladstone

Onion

95d to harvest

Sweet, mellow Gladstone onions bloom with a clean, golden fragrance and a gently crisp bite that turns especially inviting when roasted or caramelized. The bulbs mature in about 95 days to a handsome, globe-to-flat shape with warm, papery skins and a tender interior texture that holds its integrity for slicing, layering, and slow-simmered sauces. Grow Gladstone for reliable, market-ready bulbs that shine in fresh salads, savory roasts, and quick pickles alike.

Crop Dates

Growing note: In frost-free Zone 11b, grow this cool-season crop during the cooler dry season (October–February).

Milestone	Date
Start Indoors	—
Climate	Frost-Free Climate
Transplant / Sow Outdoors	Oct 1st
Harvest Begins	Jan 4th
Harvest Ends	Feb 28th

Crop Details

Trait	Value
Days to Maturity	95
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

Frequently Asked Questions

What pest or disease is most common on onion (Allium cepa), and what should I do if I see it?

Onions (Allium cepa) commonly get downy mildew (gray-violet growth on leaves) and botrytis/neck rot when plants stay wet. Remove and discard infected leaves or bulbs, improve airflow by thinning and spacing, and avoid overhead watering—water at the soil line. If you see repeated mildew pressure, use a labeled fungicide for onions and follow the product’s interval.

How often should I water onion bulbs during the main growing phase (mid-season)?

During the main bulb-filling phase, keep soil consistently moist but not soggy—aim for about 1 inch (2.5 cm) of water per week, split into 2–3 watering days during dry spells. Let the top few centimeters of soil dry slightly between waterings to prevent rot, especially as the bulbs start to enlarge. Stop regular watering 7–14 days before harvest so skins cure properly.

How can I tell when onion (Allium cepa) is ready to harvest?

Harvest when about half the tops have fallen over and the necks feel dry and tight, typically around 95 days from planting for this crop. Bulbs should have fully formed skins and a papery outer layer. Lift on a dry day, cure the onions in a warm, airy spot for 1–2 weeks, and store only after necks are fully dried.