How Long Do Red Onions Take to Grow?

Understanding the Growth Cycle of Red Onions

Red Onion Growth Cycle

Red onions are one of the most popular types of onions and are widely used in dishes worldwide. These onions can take anywhere from 90 to 120 days to mature from a seedling to a fully grown onion. It’s important to know and understand the growth cycle of red onions if you want to grow them in your garden.

The Germination Stage: The first stage of the growth cycle of red onions starts with germination. Germination is the process of the seed sprouting, and the onion seed will start to grow shortly after planting. The soil must be kept moist during germination, and it can take up to 10 days for the seedling to emerge from the soil. It is essential to keep the soil moist and the temperature at around 15-20°C during this period to ensure successful germination.

The Vegetative Stage: After the germination stage, the onion plant starts to develop a root system and leaves. During vegetative growth, the onion plant focuses its energy on leaf and root growth instead of onion bulb production. It’s crucial to ensure that the plants have adequate nitrogen, phosphorus, and potassium levels at this stage to promote healthy leaf growth and develop a robust root system. The vegetative stage can last up to eight weeks, depending on various factors like temperature and light intensity.

The Bulbing Stage: Once the onion plant reaches maturity, it begins to divert its energy towards producing onion bulbs. When the onion bulb reaches a mature size, the leaves will turn yellow, indicating that the bulbs are ready for harvesting. The length of the onion bulbing stage can vary widely, but most red onion varieties take around 90 to 120 days to reach maturity. Bulb size is also affected by the number of bulbs per plant, so it’s best to have only one bulb per plant to achieve larger bulb sizes.

The Harvest Stage: Harvesting the onion bulbs is the final stage in the growth process of red onions. When the leaves start to dry out and turn brown, it’s time to harvest the onion bulbs. To prevent any damage to the bulbs, it’s vital to dig out the onion bulbs carefully by loosening the soil with a garden fork. The harvested onions need to be cured for a week or two, a process where they are left to dry in a warm, airy location where they can receive ample sunlight. Curing helps to lengthen the shelf life of the onion bulbs and improve the flavor of the onions.

In conclusion, understanding the growth cycle of red onions is essential for successful cultivation. It’s a lengthy process, but with the right care and environment, you can grow high-quality onions in your garden. From seed germination to bulb harvesting, every stage plays a crucial role in ensuring a bountiful harvest.

Factors Affecting the Growth Rate of Red Onions

red onions field

Red onions, like all plants, require specific growing conditions to thrive. The amount of time it takes for a red onion to grow to maturity depends on several factors. Some of these factors include the type of soil, amount of sunlight they receive, watering regime, plant spacing, temperature, and pests and diseases that attack them.

The type of soil is a critical determinant of how quickly onions grow. A soil that is rich in organic matter, such as compost and well-rotted manure, will typically produce onions that grow faster because the organic matter provides the nutrients that the onions need to thrive. On the other hand, soil that lacks the necessary nutrients that onions need will result in slow growth.

The amount of sunlight that the onions receive is another critical factor in determining how fast they grow. A red onion requires about six to eight hours of direct sunlight per day to grow efficiently. If they receive less sunlight than this, the growth rate will be slower. Therefore, planting the onions in a part of your garden where they receive the maximum amount of sunlight is recommended for fast growth of your crop.

The amount of water that the onions receive is also critical in determining how quickly they grow. Red onions require a consistent amount of water throughout their growing season, primarily when they are young and still forming roots. However, too much water can cause root rot and result in the onion not absorbing the nutrients required for growth. It is recommended to water the onions once or twice a week, and the amount of water should be enough to keep the soil consistently moist.

The spacing of the onion plants is equally critical in determining how quickly they grow. A wide spacing between the red onion plants allows them to receive sufficient sunlight and water. This will help the onions to produce larger bulbs faster than when they are too close together and have to compete for water and nutrients.

The temperature at which the onions are grown is also essential for their growth. A temperature range of 13°C to 24°C is ideal for red onion growth. With temperatures outside of this range, the onions either grow poorly, or there are challenges that arise, such as bolting. Bolting means the onion plant starts to flower prematurely, reducing the size and quality of its bulbs, thus slowing their growth.

Finally, pests and diseases can also impact the growth rate of red onions. White rot and onion maggots are among the pests that affect onion growth and reduce yields. Diseases like downy mildew and botrytis that cause onions to become spongy reduce their market quality or lead to early harvest for rotting. Therefore, proper pest management through regular field monitoring, crop rotation, and sanitation practices is crucial to minimize the effects of these pests and diseases on the growth rate of red onions.

How Long Do Red Onions Take to Grow?

Red Onions Growing

When it comes to growing red onions, the length of time it takes for them to mature usually depends on the variety of the onion, the soil quality, as well as the climate conditions the onions are growing under. Generally, red onions take between 90 and 120 days to reach maturity. Typically, it takes between 10 and 21 days for the seeds to emerge from the soil, and you can expect to see sprouted seedlings between 7 to 10 days after planting.

Red onions grow best in well-draining soil, so it’s important to make sure the soil you are using is not too compact, has good aeration, and is fertile with lots of nutrients. You can use either seedling trays or sow the seeds directly in the soil. For seedling trays, fill each tray with seedling mix and plant your seeds approximately 0.5 inches deep and 1 inch apart. Water the seedlings well and keep them in a well-lit area. Once the seedlings reach a height of around four inches, they will be ready to be transplanted into your garden bed.

If you are planting the seeds directly in your garden bed, you should prepare your soil by breaking it up and removing any rocks or debris. Mix some compost or well-rotted manure into your soil, and then you can plant your seeds 1 inch apart and 0.5 inches deep. Once you’ve planted all your seeds, water the bed well and keep it moist until seedlings start emerging from the soil.

The Importance of Choosing the Right Fertilizer

Red onions Fertilizer

When it comes to growing red onions, using the right fertilizer can make all the difference. Onions are heavy feeders and require a lot of nutrients to grow properly. Before you plant your onions, it’s important to add a balanced fertilizer to your soil to ensure that it has all the necessary nutrients it needs to produce healthy and vibrant onion bulbs.

One of the best fertilizers for onions is a balanced fertilizer that contains equal parts of nitrogen, phosphorus, and potassium. Add the fertilizer to the soil before you sow your seeds, or if you’ve already planted your seedlings, add the fertilizer a week or two after they have emerged from the soil.

You should also consider using fertilizers that are high in nitrogen during the early stages of growth as this can help promote leafy growth, which will help the plant to photosynthesize and produce larger bulbs. You can also use fertilizers that are high in phosphorus during the bulb-forming stage as this will help improve the size and quality of the onion bulbs.

Harvesting Your Red Onions

Harvesting Red onions

After you’ve planted your red onion bulbs, fertilized and watered them, and waited patiently for them to grow to maturity, it’s time to harvest them. Red onions are ready to be harvested when their tops start to yellow and become weak, wilt, and fall over.

To harvest your red onions, gently lift them from the soil using a garden fork. Avoid pulling on the tops as this can damage the bulbs. Once you’ve lifted the onions from the soil, allow them to dry off in the sun for a few hours before trimming off the tops and roots. Store your onions in a cool, dry, and dark area to keep them fresh for an extended period of time.

In conclusion, growing red onions can be a rewarding experience as long as you follow the right tips and techniques. Make sure you choose a variety that suits your climate conditions, take care of your soil quality, use the right fertilizer, and be patient while waiting for your onions to grow. By following these tips, you should be able to produce a healthy yield of vibrant red onion bulbs.

Harvesting Red Onions: When are They Ready?

Red onions harvest

Red onions are a great addition to any meal. They have a distinct flavor and are a staple ingredient in many recipes around the world. If you’re thinking of growing red onions in your garden, you may be wondering how long it takes for them to grow and when they are ready for harvesting.

Growing red onions takes some patience, but it’s rewarding to see them develop from tiny bulbs into fully grown onions. Typically, red onions take around 100-120 days to reach maturity and be ready for harvesting.

1. Check the tops

Onion top

One way to know when your red onions are ready for harvesting is to watch the tops. When the leaves start to yellow and fall over, it’s a sign that the onion is mature and almost ready to be picked.

You can also gently brush away the soil from the top of the onion to check the size. If the onion is the size you want and the tops are starting to fall over, it’s time to prepare for harvesting.

2. Feel the bulb

Onion bulb

Another way to check for maturity is to feel the bulb. When the onion is ready for harvesting, it will feel firm and the outer layers will be dry and papery. If the bulb is still soft and the outer layers are moist, it’s not ready yet.

3. Check the weather

Weather conditions for red onion harvest

The weather also plays a crucial role in determining when your red onions are ready for harvesting. It’s best to wait for a dry day to harvest the onions to avoid any chance of mold or rot. If the soil is too wet, it will be challenging to clean the onions, and they may not store well.

4. Timing is everything

Onion field

The timing of harvesting red onions is essential to ensure that they store well and last for an extended period. It’s best to wait until the bulbs are entirely mature and the tops have fallen over. But beware, if you leave them in the ground for too long, they may start to rot or split.

Be sure to avoid damaging the bulbs during harvesting as this can cause the onions to spoil. Once you’ve harvested your red onions, let them dry in the sun for a few days before storing them in a cool, dry place.

It’s essential to keep your onions in a dry place, away from any moisture, light, or heat sources. Stored correctly, red onions can last for up to six months.

Harvesting red onions is a rewarding process that requires some patience and attention to detail. By following these tips, you can ensure that your red onions are ready for harvesting at the right time, and you can enjoy their delicious flavor all year round.

How Long Do Red Onions Take to Grow?

red onion growth

Red onions are an easy-to-grow vegetable, which is why they are a popular choice among amateur gardeners. The time it takes for a red onion to grow, however, can vary depending on various factors, such as the climate, soil conditions, and the variety of onion planted. In general, red onions take between 90 and 120 days to grow from seed to maturity.

Varieties of Red Onions and Their Growth Rates

red onion varieties

There are several types of red onions, each with different growth rates. For example, early-maturing red onions, such as Red Baron, take around 60 to 70 days to produce bulbs. On the other hand, late-maturing varieties, such as Red Wing and Red Bull, take between 100 and 120 days. These maturation periods are also affected by the planting dates. Onions planted during the summer take a shorter time to grow compared to those planted during the winter months.

Harvesting Red Onions: How Do You Know When They’re Ready?

harvesting red onions

Once the red onions have matured, it’s time to harvest them. But how do you know when they are ready? One way is to look at the leaves. When the leaves turn yellow and begin to wither, it’s a sign that your onions are ready to be harvested. Another way is to look at the bulbs. When the bulbs are firm and the tops have fallen over, it’s time to pick them up and cure them.

Curing and Storing Red Onions

curing red onions

Curing is the process of allowing the onions to dry out before storing them in a cool, dry place. This helps to prolong their shelf life and maintain their quality. To treat red onions, you should lay them out in a single layer in a warm, dry, and well-ventilated area for around two to three weeks. During this time, the outer layers of the onion will dry out and form a protective layer, which helps prevent decay and rot during storage. After the curing process is complete, store the red onions in mesh bags or containers in a cool, dry place away from direct sunlight.

How to Extend the Shelf Life of Red Onions

Storing red onions

If you want your red onions to last longer, follow these simple rules while storing them. First, store them in a place with a consistent temperature of 45 to 55 degrees Fahrenheit. Second, ensure they are stored in a dry area. Don’t store them in a place where humidity is high, such as the refrigerator. Finally, avoid storing them near other produce that produces ethylene gas, such as apples and bananas. This gas causes onions to ripen quickly and go bad.


Red onions take between 90 and 120 days to grow from seed to maturity depending on various factors such as soil conditions, climate, and the onion variety planted. Ensure you choose a good variety, plant them at the right time, and give them optimal growing conditions to grow healthy. Lastly, store your onions properly by first curing them and then storing them in a cool, dry area away from other produce that releases ethylene gas.