Copra

Onion

100d to harvest

Copra yellow onions open with a bright, honeyed aroma and a crisp, juicy bite that turns sweet and mellow when warmed. The bulbs form a handsome, uniform globe with warm golden skins and tight, fine-textured layers—ideal for everyday use in fresh salads, savory roasts, and slow-simmered sauces, as well as classic pickling for tangy crunch.

Crop Dates

Milestone	Date
Start Indoors	Mar 6th
Last Frost	May 15th
Transplant / Sow Outdoors	May 1st
Harvest Begins	Aug 9th
Harvest Ends	Sep 1st

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

Frequently Asked Questions

What pest or disease is most common on Allium cepa (onions), and how do I treat it at home?

Onions (Allium cepa) are commonly hit by onion maggots and, in humid conditions, downy mildew. To reduce onion maggots, cover seedbeds/transplants with fine insect netting and remove any infested plants immediately; use a soil drench with labeled products if available in your area. For downy mildew, improve airflow and avoid wetting the foliage, then apply a copper-based fungicide early at the first purple/gray downy patches, following the label exactly.

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

During active bulbing (after plants are established and tops are growing), keep the soil evenly moist but not soggy—aim for about 1 inch (2.5 cm) of water per week, adjusted for rainfall and heat. Water deeply so moisture reaches the root zone, and let the top 1–2 inches (2.5–5 cm) of soil dry slightly between waterings to prevent rot and disease.

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

Harvest when the onion tops begin to fall over naturally and the necks start to dry down, usually around your ~100-day maturity window. Lift a few bulbs to check: skins should be papery and the outer layer fully colored, with firm bulbs and tight necks before curing.