Short answer: store apples and root vegetables cold and humid, in slatted or vented wooden bins raised off the floor with air space around them. Keep apples at about 32–38 °F (0–3 °C) with high humidity, potatoes at 38–40 °F (3–4 °C) in the dark, and carrots, beets and other roots as close to 32 °F (0 °C) and as humid as you can manage. Keep apples away from potatoes and carrots: the ethylene gas apples give off makes potatoes sprout and carrots bitter. Sort out damaged produce first, and check the bins every week or two.
Storage conditions by crop
Figures differ a little between sources: USDA's commercial storage handbook (Agriculture Handbook 66) aims for ideal cold rooms, and extension guides allow for home cellars. The ranges below cover both.
| Crop | Temperature | Relative humidity | Typical storage life |
|---|---|---|---|
| Apples (late varieties) | 30–40 °F (−1 to 4 °C); 32–38 °F at home | 90–95% | 1 to several months, by variety |
| Potatoes (cured, late crop) | 38–40 °F (3–4 °C) | 90–95% | 5–10 months |
| Carrots (topped) | 32 °F (0 °C) | 95–100% | 4–6 months or more |
| Beets, turnips, rutabagas, parsnips | 32 °F (0 °C) | 95% or higher | About 1–6 months, by crop |
| Storage onions | 32 °F (0 °C) | Dry, about 65% | 6–9 months |
| Winter squash, pumpkins | 50–55 °F (10–13 °C) | Dry, about 60% | 2–6 months |
The last two rows are a warning, not a bin plan. Onions and squash want dry air, so keep them out of a humid root cellar entirely.
Prepare the crop before it goes in
- Apples: pick late-season varieties just before peak eating ripeness, handle them like eggs, and store only sound fruit with unbroken skin. Wisconsin Extension notes that wrapping fruit individually in paper helps it keep.
- Potatoes: dig after the vines die. Cure them at 45–60 °F (7–16 °C) and 85–95% humidity for about 2 weeks to heal cuts and toughen the skin, then cool them to storage temperature. Store them dark: light turns them green. Below about 38 °F (3 °C) they tend to turn sweet.
- Carrots and other roots: cut the tops off and brush off excess soil. Store them packed in damp sand, sawdust or peat, or in perforated plastic liners, to hold humidity.
- Everything: discard or eat at once anything bruised, cut or showing rot. Decay spreads through a bin.
What not to store together
- Apples and pears give off ethylene, which makes potatoes sprout, carrots bitter, and cabbage yellow. USDA lists apples with potatoes, carrots or onions as combinations to avoid.
- Onions, cabbage and turnips give their odors to apples and pears.
- If you have one cellar, put the apples in the coldest, best-ventilated corner, or cover their bins with perforated plastic and keep them well away from the roots.
Choosing and sizing wooden bins
Wood is the traditional choice because it breathes, buffers humidity and stacks well. What matters is airflow and depth.
| Bin | Size | Best for |
|---|---|---|
| Bushel crate | About 1¼ cu ft (35 L) | Small harvests; holds about 40–48 lb (18–22 kg) of apples or about 60 lb (27 kg) of potatoes |
| Plywood Pallet Bin | 47 × 47 in (119 × 119 cm), 24 in (61 cm) inside depth | Apples and pears: the classic fruit-bin depth |
| Plywood Pallet Bin · 47 × 40 | 47 × 40 in (119 × 102 cm), 24 in deep | Fruit, where a narrower footprint fits better |
| Slatted Wooden Pallet Bin | 47 × 40 in, 36⅝ in (93 cm) tall | Produce that needs maximum airflow; open slat gaps on every side |
| Plywood Pallet Bin for Vegetables | 47 × 47 in, 42 in (107 cm) sides | Potatoes and firm roots, which tolerate deeper piles |
Depth matters. Fruit at the bottom of a deep pile bruises under the weight above it, which is why the 1971 USDA / American Plywood Association plans settle on 24 in (61 cm) of depth for most fruit, and go to 42 in only for the vegetable bin. A standard 47 × 47 in fruit bin is usually rated at about 20 bushels, roughly 800–900 lb (360–410 kg) of apples, so it's a forklift or pallet-jack load when full. For a home cellar moved by hand, fill large bins in place, or use several bushel crates.
Airflow, stacking and placement
- Get off the floor. Set bins on stringers, pallets or 2×4 sleepers so air moves underneath. The plywood pallet bin's slotted floor gives 100 sq in (645 cm²) of opening for this.
- Leave a gap of a few inches between bins and between bins and walls. Exterior walls are where condensation and freezing start.
- Stack on the bin corners. Pallet bins are built to stack, with 4×4 corner posts carrying the load. Keep stacks straight and stable, and don't stack hand-moved crates more than a few high.
- Vent the room low and high. In a root cellar, a low cold-air intake and a high exhaust let you pull in cold night air in autumn and close up when it's freezing outside.
- Keep humidity up. Damp gravel or an earth floor, a pan of water, or occasionally wetting the floor all help. Dry air shrivels apples and roots within weeks.
- Measure it. A min/max thermometer and a cheap hygrometer at bin height tell you more than guessing. Keep produce above about 30 °F (−1 °C) so it doesn't freeze.
Frequently asked
Can I store apples and potatoes in the same cellar?
You can, but not side by side. Separate them as far as possible, ventilate well, and expect potatoes to sprout sooner.
How deep should an apple bin be?
About 24 in (61 cm) of fruit is the traditional limit before bottom fruit bruises. Potatoes tolerate deeper piles.
Do bins need a lid?
Not usually. Leave them open for airflow, or drape perforated plastic or burlap over them to hold humidity and keep light off potatoes.
Storage figures from USDA Agriculture Handbook 66 and University of Wisconsin Extension (A3823); ranges vary by variety, so watch your crop and adjust.