Why You Should Store Onions Away from Potatoes

Should onions be stored with potatoes?

No Onions and Potatoes should not be stored together. While there is some debate of the effects of ethylene, a naturally occurring gas produced by certain fruits and vegetables, on potatoes and onions what is obvious is that by being stored together their sprouting and decay is hastened. Potatoes should be stored in a dry place while onions actually last longer if kept in the refrigerator.

The Truth of Storing Onions and Potatoes in Regards to Ethylene Gas

Many of the articles you find online will state that the reason you should not store onions and potatoes together is that onions release Ethylene which will hasten the sprouting of potatoes. At the same time other articles say that onions do not produce Ethylene.

Because of this I decided to look further into actual research conducted by various universities.

In the first document I examined the UC SanDiego School of Medicine indicates in their flyer that potatoes are only minimally affected by ethylene. That same publication indicates that Onions are not ethylene producers and that they are sensitive to ethylene.

However, this is in direct contradiction to this article produced by Gebhard Bufler and hosted in the Annals of Botany. In his article Gebhard Bufler indicated that onions did produce small amounts of ethylene similar to that produced by potatoes. 

His research indicated that this production of ethylene coincided with the onion bulbs sprouting almost as a timing mechanism. If additional ethylene was applied the onions took longer to sprout. While inhibiting this ethylene release would cause the onions to sprout faster.

In his research he cited Irena Rylski in a study that indicated a similar type effect on potatoes. During that study it was indicated that while potatoes do produce ethylene it is more of a timing mechanism. Disturbing this natural amount can either hasten or delay sprouting depending on the concentration.

The Results of My Investigation into Ethylene Gas on Onions and Potatoes

Based on the research I located I feel that storing onions and potatoes together is likely to cause issues due to disturbing the natural levels of ethylene produced by both potatoes and onions.

Combining these two items in a small space is likely to cause premature sprouting; however, it is important to note that this same effect is likely if the potatoes or onions are stored in a confined air space on their own.

This means that if you were to store your potatoes in closed buckets they are more likely to sprout sooner than if you left them sitting in an open topped crate. The same goes for onions and being in an enclosed space.

Is Ethylene the Only Reason You Should Not Store Onions and Potatoes Together?

Another argument that arises when discussing storing onions and potatoes together is that they both release moisture and this causes rot. 

While it is true that both release moisture this is no more a factor between onions and potatoes than it would be with a larger harvest of just potatoes or just onions. The same moisture levels would be there.

The real reason beyond ethylene to store them separately is that both onions and potatoes prefer different conditions.

While both prefer dark dry places their temperature needs vary. Check the following chart for a rough comparison on their expected storage times in various conditions.

	Room Temp	Dark 50-60 Degrees	Refrigerator	Freezer
Onion	1 – 2 weeks	1-2 months	3-4 months	6-9 months
Potato	1 – 2 weeks	3-6 months	2-3 weeks effects taste	Only if Cooked

As you can see from the chart, onions actually do better if stored in the refrigerator. This will inhibit them from sprouting. At the same time potatoes last longer when stored in a dark corner of the pantry.

In both cases if possible make sure that air can flow around both potatoes and onions. This will help minimize the effects of ethylene.

Conclusion of Why You Shouldn’t Store Onions with Potatoes and How It Effects Storage Life

While it is not the sole cause of sprouting and decay ethylene does play a role in the sprouting times and beginnings of decay on both onions and potatoes.

The main take away both for the everyday person and the prepper in you is that they should be stored separately in accordance with their preferred environment.

Keep your onions in the crisper drawer of the refrigerator and your potatoes in the bottom back of your pantry, or better yet a root cellar if you have access to one.

Last, keeping your onions and potatoes separate does not extend to when it is time to eat them. Fried Potatoes and Onions are a delicious combo.