How to Properly Store Onions in Winter: Main Causes of Spoilage and Tips

Many gardeners face the problem of onion spoilage during winter storage. Even carefully grown and harvested onions can start to rot within a few months if the basic storage rules are not followed.

This is reported by AgroReview

Drying the Harvest — The First Step to Success

The main condition for long-term storage of onions is proper and thorough drying after harvesting. It is best to lay the bulbs out in a single layer in the open air. Sunlight and wind will ensure even drying within a few days, especially if the vegetables are periodically turned.

In case of rainy weather, it is advisable to move the onions to a well-ventilated area: a garage, shed, or porch. The main requirement is quality air circulation, without which the drying process loses its meaning. Some gardeners hang bunches of onions, which is also effective. When the bulbs feel dry to the touch, the roots and green tops are trimmed, after which the vegetables are ready for storage.

Choosing and Preparing for Storage

Before storing onions for the winter, it is essential to sort through the harvest.

“One rotten onion can infect all the neighboring ones, and then the entire stock.”

Discard vegetables with spots, mechanical damage, soft sides, or signs of disease.

For winter storage, late varieties that mature in August-September and can last until spring are most suitable. Yellow onions store the best, while red and white varieties are less resistant to spoilage. Choose medium-sized, firm bulbs with dry skins, free from sprouts, greens, and signs of mold.

Optimal Conditions and Containers for Storage

Onions should be stored in a cool, dry, and dark place with a temperature of +7 to +13°C and humidity of 60–70%. Excess moisture leads to rot. The best places for storing the harvest are basements, cellars, glazed balconies, or unheated garages. Storing in the refrigerator is less effective due to increased humidity and poor ventilation.

It is not recommended to keep onions near potatoes: potatoes release excess moisture, which accelerates onion rot. Therefore, it is better to keep the vegetables separate.

Plastic bags are categorically unsuitable for storage, as they do not allow air to pass through and contribute to the accumulation of condensation. A proven method is to use nylon stockings or tights, which provide good ventilation. Woven baskets, nets, wooden boxes with holes, or cardboard boxes with ventilation holes are also suitable. The main thing is to ensure air access to each onion so that the harvest lasts until spring.

For Reference:

Onions can be stored for up to 6–8 months under appropriate conditions. They contain phytoncides — natural substances that inhibit the development of bacteria and fungi, allowing the vegetable to remain suitable for consumption for a long time. At the same time, these compounds can affect other vegetables, so isolated storage is recommended.