Onions are a staple ingredient in many recipes, adding flavour and depth to dishes of all kinds. Whether you grow your own onions or buy them from a local farmers’ market, knowing when to harvest them is crucial to ensuring they last through the winter months. Harvesting onions too early can result in smaller bulbs, while leaving them in the ground too long can cause them to rot or sprout. In this article, we’ll look at the ins and outs of harvesting onions for winter storage, including when to lift them out of the ground, how to cure and store them, and tips for maximising their shelf life.
Understanding onion growth and storage
Before we get into the specifics of when to harvest onions for winter storage, it’s important to have a basic understanding of onion growth and storage. Onions are biennial plants, which means they have a two-year life cycle. In their first year, they grow foliage and store energy in the form of a bulb. In the second year they use this energy to produce a flower stem and seeds.
Onions are usually classified as either long or short day varieties, based on the amount of daylight they need to form bulbs. Long day onions need 14-16 hours of daylight to form bulbs, while short day onions only need 10-12 hours. It’s important to choose the right type of onion for your region, as planting the wrong type can result in small or underdeveloped bulbs.
Once the onions have reached maturity and are ready to be harvested, they need to be properly cured and stored to ensure they last through the winter months. Curing allows the outer layers of the onion to dry and form a protective layer, while storage conditions must be cool, dry and well ventilated to prevent rot and sprouting. By understanding the basics of onion growth and storage, you’ll be better equipped to determine the optimal time to harvest your onions for winter storage.
Ripeness of onions
When harvesting onions for winter storage, one of the most important factors to consider is maturity. Harvesting onions too early can result in small or underdeveloped bulbs, while leaving them in the ground too long can cause them to rot or sprout. So how can you tell when your bulbs are ready to harvest?
One of the first signs that an onion is ripe is when the tops start to yellow and fall over. This indicates that the onion has stopped growing and is redirecting its energy into bulb development. At this point you can gently lift the onion from the soil and inspect the bulb. The bulb should be firm and well formed, with a papery outer layer. If the bulb is still small or soft, it’s not ready for harvesting.
Another way to determine onion maturity is to cut into the bulb. The centre of the onion should be fully developed and not too soft or watery. If the centre is still developing or the onion is too watery, it needs more time in the soil.
It’s also important to consider the weather and growing conditions when determining onion ripeness. If the weather has been particularly wet or cool, onions may take longer to ripen. Conversely, if conditions have been hot and dry, onions may ripen more quickly.
By paying attention to these signs of onion maturity, you’ll be able to determine the optimum time to harvest your onions for winter storage.
Factors influencing the harvesting time of onions
While there are some general guidelines for when to harvest onions for winter storage, there are several factors that can affect the timing of the harvest. Here are some key factors to consider:
- Variety of onion: Different varieties of onion have different ripening times, so it’s important to choose a variety that is well suited to your climate and growing conditions.
- Planting date: The date you plant your onions can also affect the time of harvest. Onions planted earlier in the season may ripen more quickly, while those planted later may take longer to ripen.
- The weather: Weather conditions can have a major impact on the growth and ripening of onions. Cooler temperatures and wet weather can slow onion growth, while hot and dry conditions can speed it up.
- Soil type: The type of soil you grow your onions in can also affect their growth and ripeness. Onions prefer well-drained soil with a pH between 6.0 and 7.5. If your soil is too acidic or too alkaline, this can affect the growth of your onions.
- Fertilisation: Proper fertilisation can also affect onion growth and ripeness. Onions need a steady supply of nitrogen to grow, but too much nitrogen can result in soft, watery bulbs.
By taking these factors into consideration, you’ll be better equipped to determine the optimal time to harvest your onions for winter storage. Remember that every growing season is different, so it’s important to pay attention to the specific conditions in your garden and adjust your harvesting time accordingly.
Harvesting of onions for winter storage
Once you’ve decided that your onions are ripe and ready to harvest, it’s time to think about how to prepare them for winter storage. Here are some tips on harvesting onions for winter storage:
- Timing: The optimum time to harvest onions is usually when the tops have yellowed and fallen over. This indicates that the onion has stopped growing and is ready to be lifted from the ground.
- Lift gently: When harvesting onions, it’s important to lift them gently from the soil to avoid damaging the bulbs. Use a garden fork or trowel to loosen the soil around the onion and then lift it gently from the ground.
- Dry: Once you’ve lifted your bulbs out of the ground, it’s important to let them dry in the sun for a few days. This will help to cure the onions and prepare them for winter storage.
- Cut back the tops: Once the onions have dried for a few days, it’s time to cut the tops back to about an inch above the bulb. This will prevent moisture from collecting around the bulb and causing it to rot.
- Curing: After cutting back the tops, it’s time to cure the bulbs. This involves storing them in a dry, well-ventilated area with good air circulation. A garage or shed works well. Spread the onions out in a single layer and turn them occasionally to ensure even drying.
By following these steps, you’ll be able to successfully harvest and prepare your onions for winter storage. Properly harvested and cured onions can last for several months, providing a delicious and nutritious addition to your winter meals.
Curing and storage of onions
Once you’ve harvested and dried your onions, it’s time to cure and store them for the winter. Proper curing and storage is essential to ensure that your onions last through the winter months without rotting or sprouting. Here’s how to do it:
- Curing: Curing is the process of allowing the onions to dry completely before storing them. Once you’ve cut the tops off your onions, spread them out in a single layer in a dry, well-ventilated area. The temperature should be between 70-80°F with low humidity. Curing usually takes 2-3 weeks and you should turn the onions occasionally to ensure even drying.
- Check that they are ready: After a few weeks of curing, check that the onions are ready. The outer skin should be dry and papery and the neck should be firm. If the neck is soft or the skin is still moist, continue curing for a few more days.
- Storage: Once your onions are fully cured, it’s time to store them for the winter. Choose a cool, dry and well-ventilated place to store them. A root cellar or garage works well. Make sure you store the bulbs in a single layer and avoid stacking them as this will cause moisture to build up and lead to rot.
- Inspection: Check your bulbs regularly throughout the winter to ensure they are still in good condition. Remove any onions that show signs of rot or sprouting to prevent them from spreading to the rest of the crop.
By curing and storing your onions properly, you can enjoy them throughout the winter months. Onions are a versatile ingredient that can be used in a wide range of recipes, from soups and stews to roasted vegetables and savoury pies. With a little planning and preparation, you can enjoy the flavour and nutrition of home-grown onions all winter long.
Tips for maximising onion shelf life
Proper curing and storage are critical to maximising the shelf life of your onions, but there are a few additional tips you can follow to ensure your onions last as long as possible. Here are some tips on how to maximise the shelf life of onions:
- Keep them cool and dry: Onions should be stored in a cool, dry, well-ventilated place. The ideal storage temperature is between 32-40°F. Avoid storing onions in areas that are too warm or humid as this can cause them to sprout or rot.
- Avoid stacking: When storing onions, avoid stacking them on top of each other. This can cause pressure points which can lead to bruising or rot.
- Check regularly: Check your onions regularly for signs of rot or sprouting. Remove any onions that show signs of damage to prevent them from spreading to the rest of the crop.
- Separate from potatoes: Onions should be stored separately from potatoes as potatoes release moisture and gases that can cause onions to spoil more quickly.
- Use the right containers: Onions should be stored in breathable containers such as mesh bags or baskets. Avoid storing onions in airtight containers or plastic bags, as this can trap moisture and lead to spoilage.
By following these tips, you can extend the shelf life of your onions and enjoy them well into the winter months. With a little care and attention, your home-grown onions can provide a delicious and nutritious addition to your meals all winter long.
Harvesting onions for winter storage can be a rewarding and satisfying experience, but it’s important to know when to lift them out of the ground and how to look after them properly to ensure they survive the winter months. By paying attention to key factors such as onion variety, planting date, weather and soil type, you can determine the optimal time to harvest your onions for winter storage. And by following proper curing and storage techniques, you can extend the shelf life of your onions and enjoy them well into the winter months.
Remember to keep your onions cool, dry and well ventilated and check them regularly for signs of damage or spoilage. With a little planning and preparation, you can enjoy the flavour and nutrition of home-grown onions all winter long.
Q: How can I tell when my onions are ready to be harvested for winter storage?
A: Look for yellowing and flopping over of the tops, indicating that the onion has stopped growing. Check the bulb for firmness and well-defined shape. Cut into the bulb to check whether the center is fully developed or not.
Q: Can I store onions in a plastic bag?
A: It’s not recommended to store onions in a plastic bag, as this can trap moisture and lead to rot. Onions should be stored in breathable containers, such as mesh bags or baskets.
Q: How long can onions be stored for winter?
A: Properly cured and stored onions can last for several months, up to six months or more, depending on the variety and storage conditions.
Q: What temperature is ideal for storing onions for winter?
A: Ideal storage temperature for onions is between 32-40°F. Onions should be stored in a cool, dry, and well-ventilated area.
Q: Can I store onions and potatoes together?
A: It’s not recommended to store onions and potatoes together, as potatoes release moisture and gases that can cause onions to spoil more quickly.