The most effective way to keep potatoes from sprouting is to store them in a cool, dark place with good airflow. Temperatures between 38°F and 45°F are ideal for fresh potatoes, and complete darkness is essential. With the right conditions, most potato varieties will stay dormant for weeks or even months. But temperature and light are just the starting point. Several other tricks, including one involving apples, can extend storage life even further.
Why Potatoes Sprout in the First Place
Every potato has a built-in dormancy period, a stretch of time after harvest when the tuber simply won’t sprout no matter what. Once that window closes, internal biochemical changes kick in: the potato’s metabolism speeds up, sugars accumulate, and the growing points (the “eyes”) start developing into sprouts. This shift is driven by hormones. While the potato is dormant, it maintains high levels of a growth-suppressing hormone. As that hormone breaks down over time, cell division resumes and sprouts emerge.
How long dormancy lasts depends heavily on the variety. In comparative studies, the Agata cultivar had a dormancy period of only about 15 days, while Kennebec lasted around 54 days and Agria about 62 days. That means some potatoes you buy are already closer to sprouting than others, and there’s no reliable way to tell from looking at them. The storage conditions you provide after purchase are what determine how much extra time you get.
Temperature Is the Single Biggest Factor
Cold slows down every metabolic process that leads to sprouting. The University of California’s Integrated Pest Management program recommends holding fresh market potatoes at 38°F to 45°F for long-term storage. That’s the range of a typical refrigerator, though most home fridges sit around 37°F to 40°F.
There is a tradeoff. Cold storage below about 40°F converts some of the potato’s starch to sugar, which can cause a sweeter taste and darker browning when you fry them. If you primarily roast, boil, or mash your potatoes, this isn’t a concern. If you’re making fries or chips and want to avoid excess browning, aim for the warmer end of that range (around 42°F to 45°F), or store them in a cool pantry, basement, or garage where temperatures hover around 50°F. Even at 50°F, sprouting is dramatically slower than at room temperature.
Wherever you store them, avoid temperature swings. Moving potatoes from cold to warm and back again accelerates the metabolic changes that end dormancy.
Keep Potatoes in Complete Darkness
Light does two harmful things to potatoes: it encourages sprouting and it triggers the production of glycoalkaloids, the bitter, potentially toxic compounds that accompany greening. Research published in Frontiers in Plant Science found that blue and red wavelengths of light (both present in ordinary daylight and most indoor lighting) were effective at inducing both chlorophyll and glycoalkaloid accumulation. Levels of these toxic compounds were detectable by day four of light exposure and reached their highest concentrations after seven days. Potatoes kept in darkness produced none.
This means a countertop, a shelf near a window, or an open pantry with a light are all poor choices. A closed paper bag, a cardboard box with the lid on, or a dark cabinet all work well. Avoid sealed plastic bags, which trap moisture and promote rot.
The Apple Trick Actually Works
You may have heard conflicting advice about storing fruit near potatoes. Here’s what the research actually shows: ethylene gas, the ripening signal released by fruits like apples, inhibits potato sprouting rather than promoting it. This is counterintuitive, since ethylene speeds up ripening in most produce, but potatoes respond differently.
A 2024 study published in Heliyon tested this directly by storing potatoes alongside apple fruit at room temperature. Potatoes stored with apples had significantly less sprouting than potatoes stored alone. In one trial, sprouting dropped from 70% in the control group to 45% in the apple group. The researchers concluded that apple fruit can serve as an effective, chemical-free sprout suppressant.
To use this at home, place one or two ripe apples in with your potatoes in a ventilated bag or box. Replace the apples as they soften and stop releasing ethylene. This won’t match the performance of cold storage, but it’s a useful addition, especially if you’re storing potatoes at room temperature.
Don’t Store Potatoes With Onions
While ethylene itself suppresses potato sprouting, onions are still poor storage companions. Onions release moisture and gases that raise humidity in enclosed spaces, promoting rot in both vegetables. The high-moisture environment is the real problem. Keep them in separate containers or different areas of your pantry.
Peppermint Oil as a Natural Sprout Inhibitor
If you’re looking for a more active approach, peppermint essential oil has shown strong sprout-suppressing effects. A 2023 study in the Journal of Food Science and Technology found that peppermint oil vapors inhibited potato sprouting even in the presence of a chemical that artificially triggers sprout growth. The effect persisted for an additional 30 days after the oil was removed, showing genuine residual protection.
The researchers applied the oil by placing a few drops on a small piece of paper inside a sealed container. At home, you could place a cotton ball with several drops of food-grade peppermint essential oil inside a closed (but not airtight) storage container and refresh it every few weeks. This approach is used commercially in organic potato storage, where a related compound called carvone (naturally found in mint oils) serves as an approved sprout suppressant.
Humidity and Airflow
Potatoes need relatively high humidity to avoid shriveling, somewhere above 85%, but they can’t sit in moisture or they’ll rot. The best approach is a container that breathes: a paper bag with the top loosely folded, a burlap sack, a wooden crate, or a cardboard box with a few holes. Never use sealed plastic. If your storage spot is very dry (common in heated homes during winter), a damp towel draped loosely near (not touching) the potatoes can help.
When a Sprouted Potato Is Still Safe to Eat
Small sprouts don’t automatically make a potato dangerous, but the sprouts themselves concentrate glycoalkaloids at extremely high levels, ranging from 2,000 to 7,300 mg per kilogram of sprout tissue. For context, the widely accepted safety limit for whole potatoes is 200 mg/kg, and toxic symptoms like nausea, vomiting, and abdominal pain can begin at a dose of about 1 mg of glycoalkaloids per kilogram of your body weight.
If a potato has small sprouts (under half an inch) and is still firm, you can cut the sprouts off completely, removing a generous margin of the surrounding flesh, and eat the rest safely. If the potato is soft, wrinkled, or extensively sprouted, or if the flesh beneath the skin has turned green, discard it. The green color itself is chlorophyll (harmless), but it forms under the same conditions as glycoalkaloids and reliably signals elevated levels. Peeling removes a significant portion of glycoalkaloids since they concentrate near the skin, but it won’t eliminate them entirely from a badly affected potato.
Quick-Reference Storage Checklist
- Temperature: 38°F to 45°F for maximum shelf life; up to 50°F in a cool pantry if refrigeration isn’t an option
- Light: Total darkness, using a paper bag, closed box, or dark cabinet
- Container: Breathable material like paper, cardboard, or burlap, never sealed plastic
- Companions: An apple or two can help suppress sprouting; keep onions separate
- Optional boost: A few drops of peppermint essential oil on a cotton ball inside the storage container
- Inspection: Check weekly and remove any potatoes that are softening, greening, or showing rot before they affect the rest