How Many Onions Grow From One Bulb?

on January 26, 2023

Onions are a staple in many kitchens around the world, and for good reason. They add flavor and depth to a wide variety of dishes, and they’re also relatively easy to grow in a home garden. But have you ever wondered how many onions you can expect to get from one bulb?

On average, one onion bulb will produce about one new onions. Preformed bulbs are often sold at garden centres and referred to as onion sets. The primary advantage of the onion set is that it goes a little bit faster in the earlier part of the season and we’ll give an earlier harvest to the gardener. The disadvantage of using an onion set is it is significantly more expensive than growing onions from seed.

Additionally, growing onions from onions sets is also less space efficient and grown from seed because you can plant the onions in clumps which is a technique that is promoted by the well-known gardener Charles Dowding.

What Time Of Year Should Onion Sets Be Planted?

Onion sets, which are small bulbs that have been grown from seed the previous year, should be planted in the late winter or early spring. The ideal planting time varies depending on the climate and growing conditions in your area, but a general guideline is to plant them as soon as the soil can be worked.

In areas with moderate climates, onion sets can be planted as soon as the soil can be worked in late winter or early spring, while in colder climates, they should be planted a bit later in the spring, after the last frost date. In areas with hot summers, it’s best to plant onion sets in the fall for a spring harvest.

It’s also important to note that onions, like many other vegetables, prefer well-drained soil, and cool temperatures to grow best, so it’s recommended to plant them as early as possible to take advantage of this.

How Long Does It Take For Onions Grown From Onion Sets To Reach Maturity?

Onions grown from onion sets typically take between 60 to 90 days to reach maturity, depending on the variety of onion and the growing conditions. The ideal time to harvest onions is when the tops have started to fall over and turn brown. This is a sign that the bulbs have reached maturity and are ready to be harvested.

However, the actual time it takes for the onions to reach maturity will depend on the temperature, sunlight, and soil conditions. In general, onions grown in cooler temperatures will take longer to mature than those grown in warmer temperatures. Additionally, onions that are grown in full sun will generally mature faster than those grown in partial shade.

However, it’s important to know that onions are one of few vegetables that can be harvested at any point during its development and used in cooking so you can take an early harvest of spring onions or small bulbs or alternatively allow them to grow to full maturity.

How To Grow Onions From Seed?

Growing onions from seed is a more economical way of growing a large number of plants, and it also allows you to have a wider range of varieties to choose from. However, it takes a bit longer to grow onions from seed than from bulbs, as the seedling stage takes longer.

When growing onions from seed, it is important to start them indoors about 6-8 weeks before the last frost date. To do this start by filling the seed tray with a good quality seed raising mix and then plant the seeds at a depth of approximately half an inch.

When planting onions we recommend that you use a modular seed tray that has individual cells. In each cell plant 5 to 6 seeds, with the aim of getting 4 to 5 seedlings coming up.

These seedlings can be planted as clumps which will grow to reasonable sized without the need to split the seedlings up. This process is significantly more efficient than planting individual seedlings in terms of space and time and is well worth doing.

Once the seedlings have developed a good root system, they can be transplanted outdoors. The clumps seedlings should be spaced about 8 to 10 inches apart, and they should be planted at the same depth as they were in the seed tray.

In terms of growing conditions, onion should ideally be planted in full sun location in rich moist and free draining soil with plenty of nutrients. If you are unsure about the quality of your soil it is best to add a bag of compost to soil before planting the seedlings which will ensure that they have all the nutrients they require during the growing season.

To ensure that the seedlings develop properly it is also important to water regularly throughout the growing season. This will ensure that you get large onions that are in good conditions. Onions grown from seed will take about 110-160 days to reach maturity, depending on the variety.

When To Harvest Onions?

There are a few obvious signs that indicate it’s time to harvest your onions:

The tops have started to fall over and turn brown: This is a sign that the bulbs have reached maturity and are ready to be harvested.

The leaves have begun to yellow and dry out: This is a sign that the onion is no longer actively growing and is ready to be harvested.
Bulbs size: Onions that have reached the desired size can be harvested.
Bulbs skin color: Onions will start to develop a papery skin, this is a sign that they are ready to harvest.

Bulbs color: Some varieties of onions have a characteristic color when they are ready to harvest like red onions will turn deep red when they are ready.

How Do I Store Onions After Harvesting?

There are a few different ways to store onions after harvesting, depending on how you plan to use them and how long you need to store them.

Room Temperature: Onions that have been fully cured (dried) can be stored at room temperature in a cool, dry, and well-ventilated area. Keep them in a mesh bag or a paper bag to allow for air circulation. They can be stored in this way for several months.

Refrigeration: Onions can be stored in the refrigerator, but they should be kept in a plastic bag to prevent moisture from collecting on them. They will last for several weeks in the refrigerator.
Freezing: Onions can also be frozen for longer-term storage. Simply chop or slice them and place them in a plastic bag or container. They can be frozen for up to 8 months.
Root Cellaring: If you have a root cellar, you can store onions there as well. They keep well in a cool, dark, and humid place.

No matter the method, be sure to store your onions in a cool, dry place to prevent them from rotting. It’s also important to note that onions that are not fully cured should not be stored with other fruits and vegetables, as the ethylene gas they produce can cause other fruits and vegetables to ripen and spoil more quickly.