When to Harvest Onions: A Guide

Photo Onions, Garden

Understanding the growth stages of onions and knowing when to harvest them is crucial for successful onion cultivation. Onions are a staple ingredient in many cuisines around the world and are known for their distinct flavor and versatility in cooking. Whether you are a home gardener or a commercial farmer, having a good understanding of onion growth stages and proper harvesting techniques is essential for maximizing yield and quality.

Key Takeaways

  • Onion growth stages include sprouting, vegetative growth, bulbing, and maturation
  • Factors affecting onion maturity include temperature, day length, and variety
  • Signs of onion maturity include yellowing of leaves, softening of neck, and dry outer skin
  • Onions should be harvested when the tops have fallen over and the outer skin is dry and papery
  • Tools and equipment needed for onion harvest include a digging fork, gloves, and a drying rack
  • To harvest onions, gently lift them out of the soil with a digging fork and let them dry in the sun for a few days
  • Curing onions is important to remove excess moisture and prevent rotting
  • Onions should be stored in a cool, dry, and well-ventilated area
  • Common mistakes to avoid when harvesting onions include pulling them out of the ground too early and not curing them properly
  • Onions can be used in a variety of recipes, including soups, stews, and salads.

Understanding Onion Growth Stages

Onions go through several distinct growth stages before they are ready to be harvested. These stages include seedling, vegetative, bulb initiation, bulb expansion, and maturity. During the seedling stage, the onion plant emerges from the soil as a small sprout. In the vegetative stage, the plant focuses on leaf growth and develops a strong root system.

The bulb initiation stage is when the onion plant starts to form the bulb that we commonly associate with onions. This stage is characterized by the thickening of the base of the plant and the formation of layers within the bulb. The bulb expansion stage is when the onion bulb grows in size and reaches its maximum potential.

Finally, the maturity stage is when the onion plant stops growing and begins to prepare for dormancy. The leaves start to turn yellow and dry out, indicating that the onion is ready to be harvested. Understanding these growth stages is important because it allows you to determine the optimal time for harvesting onions.

Factors Affecting Onion Maturity

Several factors can affect the maturity of onions, including temperature, day length, variety, and planting date. Onions are classified into short-day, intermediate-day, and long-day varieties based on their response to day length. Short-day onions require 10-12 hours of daylight to initiate bulb formation, while long-day onions need 14-16 hours of daylight.

Temperature also plays a significant role in onion maturity. Cooler temperatures can slow down onion growth, while warmer temperatures can accelerate it. The planting date is another crucial factor to consider. Onions planted earlier in the season will have a longer growing period and may reach maturity earlier than those planted later.

It is important to note that these factors can vary depending on the specific onion variety and growing conditions. Therefore, it is essential to consult the seed packet or your local agricultural extension office for specific information about the variety you are growing.

Signs of Onion Maturity: What to Look For

Signs of Onion Maturity What to Look For
Size Onions should be at least 2 inches in diameter
Color The outer skin should be papery and dry with no green tint
Texture The onion should feel firm and heavy for its size
Smell The onion should have a mild, sweet aroma
Top The top of the onion should be dry and papery
Neck The neck of the onion should be tight and dry

When determining if an onion is mature and ready for harvest, there are several physical signs to look for. The first sign is the yellowing and drying out of the onion’s leaves. As the onion reaches maturity, the leaves will start to turn yellow from the tips down towards the base of the plant. Eventually, the leaves will dry out completely.

Another sign of onion maturity is the firmness of the bulb. Mature onions will have a firm and solid bulb that does not give when gently squeezed. The neck of the onion, where the leaves meet the bulb, should also be dry and papery.

Lastly, you can check the size of the onion bulb to determine if it is mature. Onions typically reach their maximum size during the bulb expansion stage. Depending on the variety, mature onions can range in size from small pearl onions to large storage onions.

Timing is Key: When to Harvest Onions

Timing is crucial when it comes to harvesting onions. Harvesting too early can result in small bulbs with underdeveloped flavors, while harvesting too late can lead to bulbs that have started to rot or sprout. The ideal time to harvest onions is when they have reached full maturity but before they start to deteriorate.

To determine the right time to harvest, you need to consider both the variety of onion you are growing and the growing conditions. Short-day onions typically mature in 90-110 days, while long-day onions can take 100-120 days. Intermediate-day onions fall somewhere in between.

In addition to the number of days to maturity, you can also look at the physical signs of maturity mentioned earlier. Once the onion’s leaves have turned yellow and dried out, and the bulb is firm and of the desired size, it is time to harvest.

Preparing for Onion Harvest: Tools and Equipment Needed

Before you begin harvesting onions, it is important to gather the necessary tools and equipment. This will ensure that the process is efficient and safe. Some essential tools for onion harvest include a garden fork or shovel, a pair of pruning shears or scissors, and a basket or crate for collecting the harvested onions.

A garden fork or shovel is used to gently loosen the soil around the onion bulbs before lifting them out of the ground. This helps prevent damage to the bulbs during harvest. Pruning shears or scissors are used to cut off the foliage of the onion plant, leaving a short stub of about an inch.

Having a basket or crate on hand is essential for collecting the harvested onions. It is important to handle onions with care during harvest to avoid bruising or damaging them. A sturdy container will help protect the onions and keep them organized as you continue harvesting.

Harvesting Onions: Step-by-Step Guide

1. Prepare the soil: Before harvesting onions, make sure the soil is dry. This will make it easier to lift the bulbs out of the ground without causing damage.

2. Loosen the soil: Use a garden fork or shovel to gently loosen the soil around each onion bulb. Be careful not to pierce or damage the bulbs during this process.

3. Lift the bulbs: Once the soil is loosened, carefully lift each onion bulb out of the ground by grasping the foliage near the base of the plant. Avoid pulling on the foliage too forcefully, as this can cause the leaves to detach from the bulb.

4. Trim the foliage: Using pruning shears or scissors, cut off the foliage of each onion plant, leaving a short stub of about an inch. This helps the onion bulbs dry out and prevents them from rotting during the curing process.

5. Clean and sort the onions: Remove any excess soil from the harvested onions and sort them based on size and quality. Discard any onions that are damaged or diseased.

6. Cure the onions: Place the harvested onions in a well-ventilated area with low humidity to cure. This process allows the outer layers of the onion bulbs to dry and form a protective skin. Curing typically takes 2-3 weeks.

Curing Onions: Why it’s Important

Curing onions is an important step in the harvesting process because it helps extend their shelf life and improves their flavor. During curing, the outer layers of the onion bulbs dry out and form a protective skin. This skin acts as a barrier against moisture and bacteria, reducing the risk of rotting or sprouting.

Curing also allows the flavors of the onion to develop and intensify. As the onion bulbs dry, some of their moisture evaporates, concentrating their natural sugars and flavors. This results in a sweeter and more flavorful onion that is perfect for cooking.

To properly cure onions, they should be placed in a well-ventilated area with low humidity. The temperature should be around 70-75°F (21-24°C). Avoid exposing the onions to direct sunlight, as this can cause them to become sunburned and spoil.

Storing Onions: Best Practices for Longevity

Proper storage is essential for preserving the quality and longevity of harvested onions. Here are some tips for storing onions:

1. Choose the right storage location: Onions should be stored in a cool, dry, and well-ventilated area. The ideal temperature for onion storage is around 32-40°F (0-4°C), with a humidity level of 65-70%.

2. Avoid storing onions near other produce: Onions release ethylene gas, which can cause other fruits and vegetables to spoil faster. Keep onions separate from other produce to prevent premature ripening or decay.

3. Store onions in a breathable container: Use mesh bags, baskets, or crates to store onions. These containers allow air to circulate around the onions, preventing moisture buildup and reducing the risk of rotting.

4. Check for signs of spoilage regularly: Regularly inspect stored onions for any signs of rotting or sprouting. Remove any onions that show signs of spoilage to prevent the spread of decay to other onions.

Common Mistakes to Avoid When Harvesting Onions

1. Harvesting too early: Harvesting onions before they reach full maturity can result in small bulbs with underdeveloped flavors. Wait until the leaves have turned yellow and dried out before harvesting.

2. Leaving onions in the ground too long: Onions that are left in the ground for too long can start to rot or sprout. Harvest them as soon as they reach maturity to prevent spoilage.

3. Mishandling onions during harvest: Handle onions with care during harvest to avoid bruising or damaging them. Rough handling can lead to rotting or premature spoilage.

4. Storing onions improperly: Improper storage can lead to premature spoilage or loss of flavor. Follow the best practices for onion storage mentioned earlier to ensure longevity.

Using Harvested Onions: Recipes and Cooking Tips

Once you have harvested your onions, there are countless ways to use them in various recipes. Onions are a versatile ingredient that can be used in soups, stews, stir-fries, salads, and more. Here are some ideas for using harvested onions:

1. French Onion Soup: This classic soup is made by caramelizing onions and simmering them in a flavorful broth. Top it off with melted cheese and crusty bread for a delicious and comforting meal.

2. Caramelized Onions: Slowly cooking onions over low heat until they become soft, sweet, and golden brown creates a rich and flavorful topping for burgers, sandwiches, pizzas, and more.

3. Onion Rings: Slice onions into rings, dip them in a batter, and fry them until crispy. Serve them as a side dish or as a tasty topping for burgers or hot dogs.

4. Sautéed Onions: Sautéed onions add flavor to a wide range of dishes, from pasta sauces to omelets. Simply cook sliced onions in a bit of oil or butter until they become soft and translucent.

Experiment with different recipes and cooking techniques to make the most of your harvested onions. Their unique flavor can enhance the taste of any dish.

Understanding the growth stages of onions and knowing when to harvest them is essential for successful onion cultivation. By paying attention to the physical signs of maturity and considering factors such as variety and growing conditions, you can determine the optimal time to harvest your onions.

Proper harvesting techniques, including using the right tools and equipment, will ensure that the process is efficient and safe. Curing the harvested onions allows their flavors to develop and extends their shelf life. By following best practices for onion storage, you can enjoy your homegrown onions for months to come.

So why not give onion cultivation a try? With a little knowledge and some patience, you can enjoy the satisfaction of harvesting your own fresh and flavorful onions.

If you’re wondering when to harvest onions, you’ll find some helpful tips in this informative article from Lawn World. They provide valuable insights on determining the right time to harvest your onions for optimal flavor and storage. Check out their article on onion harvesting here for expert advice and guidance.


What is the best time to harvest onions?

Onions are usually ready to harvest when their tops start to yellow and fall over. This typically occurs in late summer or early fall, depending on when they were planted.

How do I know if my onions are ready to be harvested?

You can tell if your onions are ready to be harvested by checking the tops. If they have fallen over and started to dry out, it’s time to harvest them. You can also gently dig up a few onions to check their size and maturity.

What is the best way to harvest onions?

To harvest onions, gently loosen the soil around the bulbs with a garden fork or trowel. Then, pull the onions out of the ground by their tops and lay them out to dry in a warm, dry place with good air circulation.

How long do onions need to dry after harvesting?

Onions should be left to dry for at least two weeks after harvesting. This allows the outer layers to dry and the bulbs to cure, which helps them store better.

What should I do with the onion tops after harvesting?

After harvesting onions, you can cut off the tops and compost them. Alternatively, you can use them to make onion powder or stock.