Can different onion varieties be stored together?
Written by
Liu Xiaohui
Reviewed by
Prof. Charles Hartman, Ph.D.It's disheartening to have my mixed onion varieties. This was my experience when I recently had my sweet onions spoil faster sitting next to my storage varieties. Each onion variety has its own temperature and humidity requirements. So, by storing them together, I compromised their shelf life. Things worsened when I stored them next to ethylene-producing fruits.
Temperature Conflicts
- Storage onions need 32-36°F while sweets require 40-45°F. Compromising causes either sprouting or chilling damage. I now use separate mini-fridges for different types after losing crops.
Ethylene Sensitivity
- Onions absorb ethylene gas from fruits like apples accelerating sprouting. Even stored 3 feet apart ethylene travels through air. I measure 40% faster spoilage when fruits share storage space.
Humidity Mismatch
- Sweets need 70-75% humidity preventing dehydration while storage types require 60-65% preventing mold. Mixed environments satisfy neither causing shriveled or moldy bulbs.
Ethylene-producing foods such as tomatoes and apples pose special risks. Ethylene gas causes plants to sprout in a matter of weeks. I enjoy a 10-foot separation after ethylene ruined my storage onions. Do not use adjacent root cellars without a sealed (air-tight) dividing wall.
Storage containers should match your variety needs. Storage onions are best kept in mesh bags that allow airflow. Sweets can be stored in perforated plastic bags that retain moisture, keeping them fresh in the kitchen. I like to label my containers clearly, as mixing has caused dehydration problems for me in the past.
Zoned Storage Areas
- Create microclimates using separate shelving units. Use temperature-controlled drawers or insulated boxes. I maintain 3 distinct zones in my basement for different onion types.
Monitoring Systems
- Install wireless hygrometers/thermometers in each storage area. Set phone alerts for fluctuations. I check readings twice weekly during seasonal changes.
Harvest timing matters for compatibility, too. Early harvest sweets typically spoil faster than late-harvest storage types. I always keep newly harvested onions isolated for two weeks before considering mixing. This allows for the curing process to equalize moisture adjustments.
Read the full article: 7 Essential Signs for When to Harvest Onions
