How long do onion sets last?

In this article, we will answer the question “How long do onion sets last?”, and how to store onion sets?

This article also includes a brief guide on how to care for onion sets. Read on if you want to know what are the common onion set pests and diseases. 

How long do onion sets last?

Onion sets last for up to three weeks or a month if placed in a cool and dark place with no direct sunlight such as the basement or pantry.

Onion sets usually grow in the onion planting season so there is always a need to store them properly till the planting season. Selecting the type of onion bulb and storing it is the major task. 

Some opt for onion transplant and some go for onion sets. The major difference is that the onion transplants give large and big onions that take about 10 weeks to fully mature. On the other hand, in onion sets, we grow long onions with bulbs less than 1 inch wide.

To keep the set healthy, always follow proper storage practices so they could grow well when the season arrives, that is, between March and April. 

What are onion sets?

Onion sets are the onions that are not allowed to grow fully. The growers of onion set plant onion seeds very close together so the resulting onions grow very small because they are so crowded. 

Those who haven’t grown onion sets or seeds before often ask this question – how many onions grow from an onion set or seed? The answer is simple, only one onion grows from an onion set or a seed.

How to store onion sets?

First of all, take onion sets from the container and separate them based on their size; especially their bulb size. 

There will be two categories; one with a bulb size larger than a dime and; the other with a bulb size smaller than a dime.

Make a window on top of four bricks with each brick placed at the corner of the window. Place the onions on top of the screen and make a layer of it on top. Leave some space at corners and between the onion sets to allow air circulation,

Keep them in a dark, dry, and cool place to store them effectively. 

There is another three-step method that is efficient in growing onion sets till they are ready to be planted.

In the first step, take the onion sets and place them in the mesh bag. The same method could be used to store onions.

In the second step, look for a dark, dry, and cool place with no humidity. Basement is not the ideal or best choice because it is damp and can cause the rotting of the onions in the storage.

An attic, garage, or even uninsulated closet is a good place to store onion sets.

In the third step just keep on checking regularly that the onions are alright, there shouldn’t be any sign of damage or rotting or spoilage. If there is even a single case of deterioration, the whole lot will be at risk of spoilage.

If you find any bag rotting, immediately remove it from the storage and discard it otherwise it will spoil the others too. These three steps are basic and easy steps to store onion sets. 

How to care for onion sets?

Onions are very easily grown vegetables and they don’t need much attention as their foliage is minimal. The water requirement of onions in the growing season is quite high. You should take better care of onions, especially in the dry season.

In normal conditions like mild weather, mild humidity, onions require less amount of fertilizer and water. An average soil with fertilizer will do great in the growing season. Do not use nitrogen fertilizer as it will cause thick necks that will lead to neck rot.

In July, there must be an increase in the watering of onions because the onions will reserve and utilize this water in the Autumn and Winter. 

Keep the top of the onion sets as clean as possible because it contains some of the spoilage bacteria that will pose threat to the storage of onion sets. 

Onions set pest and diseases 

Different kinds of pests and diseases can spoil the onions set during planting. Damping-off is a major issue that can lead to purple blotch, fusarium basal/ twister diseases, etc

Other FAQs about Onions that you may be interested in.

How To Preserve Green Onions

What can I substitute for onion powder?

How to counteract too much onion in a recipe?


In this article, we answered the question “How long do onion sets last?”, and how to store onion sets?