Food & Culinary

Why storing potatoes near onions makes them sprout faster

Dan Kauna 02nd August, 2026 02:54 PM

Storing raw potatoes and onions together in the same kitchen basket is routine in many homes. While placing your market buys in one spot keeps things organised, this setup actually shortens the shelf life of both vegetables.

The cause is ethylene gas, a natural plant hormone that onions release as they mature.

How onions break potato dormancy

Freshly harvested potatoes start with a natural resting phase called dormancy. This resting period keeps the tubers firm and stops unwanted shoots from growing.

When stored right next to onions, the continuous release of ethylene gas forces the potato eyes to wake up too early. In a study published in Plant Physiology, researchers observed that “Relatively short-term (less than 3 days) exposure to ethylene results in the premature termination of tuber endodormancy.”

Once this resting period ends, the potato redirects its internal energy toward growing shoots. This growth causes the potato to lose moisture, shrink, and turn soft.

Multiple onions in a container have turned soft, mushy, and discoloured due to moisture buildup from nearby sprouted potatoes.

The problem goes both ways. Potatoes release moisture as they breathe. When kept in a closed bin or tight cupboard next to onions, that extra moisture softens the dry outer skins of the onions.

The trapped dampness creates ideal conditions for mould and rot, causing onions to spoil quickly.

Storage tips to keep your produce fresh

Keeping these two kitchen staples separate is a simple way to reduce food waste and protect your household budget. Preventing early spoilage ensures that purchases stay usable for much longer.

Potatoes are stored neatly in a ventilated plastic crate on one shelf, while onions are kept separately in an open wire basket above.

To store them properly, keep onions and potatoes in separate containers placed a short distance apart. Open mesh bags, traditional woven baskets, or open wooden crates allow air to move freely, clearing away trapped gas and moisture.

Onions need dry, airy spots with good ventilation. Potatoes require a cool, dark place away from light, which turns the skin green and creates a bitter compound called solanine.

Checking your storage baskets twice a week helps you remove any damaged items before rot spreads to the rest.