Onions are a versatile vegetable that can last for months if stored properly after harvest. Whether you’re growing onions for your own use or to sell at a farmers market, learning how to cure and store onions is an important skill for any gardener. Proper post-harvest care allows you to enjoy homegrown onions throughout the fall and winter when fresh local produce is scarce. This guide will walk you through the key steps of preparing onions for long-term storage after harvesting them from your garden. We’ll cover curing, drying, trimming, and storage methods to help you get the maximum shelf life out of your onion crop. Follow these tips and you’ll have onions on hand to flavor soups, stews, salads, and other dishes for months to come.
When and How to Harvest Onions
Knowing the right time to harvest is the first step to proper onion storage. Onions can be harvested in several stages:
- Green onions – Harvest green onions or “spring onions” once the stalks are at least 6 inches tall. Simply pull green onions up and use them fresh.
- Bunching onions – Bunching onion bulbs reach maturation earlier than other types. Harvest when the tops start to fall over and dry out.
- Storage onions – For full-size bulb onions like yellow, white, or red onions, it’s best to wait until the majority of the tops fall over and begin to dry out. This is usually in late summer or early fall.
Look for these signs that onions are ready for harvest:
- Tops start to fall over and turn brown
- 70% or more of the tops are bent over
- Bulbs feel firm when gently squeezed, not spongy
Use the following technique to harvest mature, dry onions:
- Loosen the onions with a digging fork or garden knife, being careful not to damage the bulbs
- Gently lift or pull the onions from the ground and lay them on the soil surface for a day or two to dry further
- Once the onion tops and roots are thoroughly dry, cut the roots off with pruners or scissors
- Brush off any excess dirt but don’t wash the bulbs yet
Leaving onions to cure in the garden for 1-2 weeks allows the outer skins to completely dry and protects the onions in storage. Don’t wash the bulbs before storing them. Let’s look more closely at the curing process next.
Curing Onions
Curing onions after harvest seals the outer skins and helps prolong freshness during storage. Proper curing requires:
- Dry conditions
- Good air circulation
- Temperatures between 70-90°F
- Curing for 1-2 weeks
Here are two methods for curing onion bulbs:
Curing Onions in the Garden
Leave onions on top of the soil for up to 2 weeks after harvesting. Cover with a mesh screen if necessary to protect from rain. Turn the onions every 2-3 days to ensure even drying. Once the tops and roots are completely dry and shriveled, the onions are cured.
Curing Onions Indoors
You can also cure onions in a garage, shed, or basement. Spread the onions in a single layer on racks, screens, or mesh bags. Make sure there is ample air circulation around the onions. Turn the onions every 2-3 days while curing indoors for 1-2 weeks.
Trimming and Storing Cured Onions
Once onions are cured, a few more steps should be taken before long-term storage:
- Trim: Use scissors or pruners to trim the tops to 1 inch above the bulb. Roots should be trimmed to just below the bulb.
- Inspect: Throw away any onions with cuts, bruises, or other damage that may lead to rotting in storage.
- Select: Choose your best, healthiest onions for long-term storage. Use any onions with flaws, bruising, or sprouting right away.
- Clean: Brush off any remaining soil. Don’t wash cured onions before storage.
Now the onions are ready to be stored using one of these methods:
Braided Onions
Artfully braiding onions is not just for decoration! Braiding creates airflow around the onions for better preservation. Simply braid the trimmed tops together into chains. Hang braided onions in a cool, dry area.
Mesh Bags
Cured onions keep well in mesh or nylon bags. Place bagged onions in a cool (32-50°F), dry location. Perforated plastic bags also work well.
Root Cellars
A root cellar provides ideal conditions for storing onions and other root vegetables. Maintain temperatures around 32-50°F with 60-70% humidity. Stack onions in shallow crates or baskets with space for air circulation.
Onion Storage Tips
Follow these guidelines for the best onion storage:
- Store at 32-50°F with low humidity
- Keep in shallow crates or mesh bags for air flow
- Choose onions free of cuts and bruises
- Check onions occasionally and remove any rotten ones
- Use onions with sprouting tops right away
Stored properly, most onion varieties will last 4-8 months. Harder, more pungent varieties tend to store longer. Never store onions below 40°F, as cold temperatures can turn the bulbs soft and mushy. With the right post-harvest curing and storage, you can enjoy fresh onions from the garden all winter long!
Preparing Other Alliums for Storage
The curing and storage process is similar for other alliums like shallots, leeks, and garlic. Here are a few specifics:
Shallots
Harvest shallots when the tops yellow and fall over. Cure bulbs spread out on racks or screens for 2 weeks. Store cured shallots in mesh bags or vented boxes at 40-50°F.
Leeks
Hill dirt up around leeks as they grow to blanch the stalks. Harvest any time before a hard freeze. Leave roots intact and store unwashed leeks in buckets of damp sand or soil in the root cellar.
Garlic
Cure freshly dug garlic for 2-3 weeks in a shady, dry spot. Brush off dirt but don’t wash. Store at room temperature with good air circulation for up to 8 months. Braid tops for attractive storage.
Onion Storage Problems and How to Avoid Them
With proper curing and storage methods, you can avoid most issues with stored onions. Here are some potential problems and solutions:
| Problem | Solution |
|---|---|
| Sprouting | Pick out sprouted onions to use right away. Check storage conditions – onions sprout from too much warmth. |
| Mold | Improve air circulation around onions. Discard moldy bulbs immediately. |
| Rotting | Remove and discard rotten onions. Improve air flow and reduce humidity levels. |
| Shriveling | Increase humidity levels in storage area. Cook with shriveled onions soon. |
| Soft onions | Avoid storing onions below 40°F. Use soft onions quickly in cooked dishes. |
With the right harvest timing, curing, and storage methods, you can enjoy onions from your garden for up to 8 months after harvest. Follow these best practices for preparing and storing onions to get the most out of your homegrown onion crop. The satisfaction of cooking with your own onions all winter makes the extra harvest care worthwhile!
Onion Storage Frequently Asked Questions
How do you keep onions fresh once harvested?
Onions stay fresh longest when properly cured and stored. Leave onions in the ground until tops are mostly dry and fallen over. Allow onions to finish curing for 1-2 weeks in a dry, well-ventilated area before storage. Store cured onions at 32-50°F.
Can you store onions and potatoes together?
It’s best not to store onions and potatoes together. Onions give off a gas that can cause potatoes to sprout more quickly. Store onions and potatoes separately for longest shelf life.
How long do onions last in the fridge?
Whole, unpeeled onions will last 2-4 weeks in the refrigerator. Once cut, onions last about 7-10 days refrigerated in a sealed container. For longer onion storage, cure bulbs fully and store outside the fridge.
What’s the best way to store green onions?
For short-term storage, place freshly cut green onions in a jar of water in the fridge. Change the water daily. For longer storage, wrap the roots separately from the green tops and refrigerate in plastic for 1-2 weeks.
Can you freeze onions from the garden?
Freezing isn’t recommended for long-term onion storage. Freezing causes texture and flavor changes. Curing and cold storage preserves fresh onions much better.
What causes onions to rot in storage?
Onions rot from damage or disease during curing, moisture during storage, temperatures too warm or cold, and poor air circulation. Inspect onions regularly and remove any rotten bulbs right away.
Conclusion
Learning how to properly cure and store onions allows you to enjoy their benefits year-round. Follow these tips for harvesting onions at the right maturity, curing them fully, and storing cured bulbs under the best temperature and humidity conditions. With the right dry, cool storage and ample air flow, homegrown onions will stay fresh for 4 months or longer after harvesting. Don’t let your onion bounty go to waste. Try braiding, mesh bags, shallow crates, or cellar storage to keep onions on hand to flavor your cooking through the winter.
