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Long Term Storage of Your SFG Potatoes, Onions, Winter Squash

By February 8th, 2024No Comments

Written by Chris McLaughlin

red onionYou did it! You grew your own food from teeny tiny seeds and now you’re wondering how you’re going to eat, freeze can or dry it all. Did you know some vegetables are great candidates for long term storage just as they are? Prepared and stored correctly, potatoes, onions, and winter squash will keep for months. 

First Steps to Smart Food Keeping

Don’t wash squash, potatoes or onions, gardeners! As you harvest, keep that in mind along with these pointers for successful long-term storage.  

  • Harvest fully mature vegetables.
  • Handle your crops gently. (No pitching them from your Square Foot Garden bed into a basket ten yards away.)
  • Give ‘em room while you harvest. Use several shallow containers as you collect your bounty, versus piling them on top of each other. 
  • Gently brush off your vegetables instead of washing or rinsing them.
  • ‘Cure’ the appropriate crops. Curing is just another way of saying ‘prepare them for storage.’ (NOTE: Not all crops require curing.) 

Potato Prep and Storage

Cure: Begin preparing your potatoes by not watering the plants the last two weeks before harvesting. This helps toughen them up for storage later. Let the vines die back completely before collecting the tubers. Gently brush soil from the potatoes and avoid washing or rinsing. Place completely dry potatoes in a dark, dry area with high humidity (85-90%) for a week. Measure your humidity with an inexpensive gauge, available online for under $20.

Store: Keep potatoes in a dark, well-ventilated area around 45-55 degrees. They like a bit of humidity (lower than the cure stage) versus a bone-dry environment, if that’s possible where you live.


Onion Prep and Storage

onion winter storage

One way to store onions? Crates with newspaper layers for circulation.

Cure: Brush off soil and debris from the bulbs and leave onion roots intact. Cut the dead tops from the onions leaving a 1” stem on top. Place them in a warm, dry, well-ventilated area for three weeks. Spread them out on newspaper so that the bulbs aren’t touching. The goal is to toughen up the outer skins without losing the moisture on the inside of the bulb.

Store: Keep onions in a well-ventilated area at 56-76% humidity (ideal) and between 45-55 degrees. Place them in hanging mesh bags, wooden or plastic open crates, or a cardboard box with ventilation holes poked into all sides of the box. Any onions that get a soft spot or look like they are going to sprout should be used immediately.


Winter Squash (But Acorn Squash Are Different)


There are many winter squash varieties you can grow vertically in your SFG.

Cure: While harvesting, brush soil off and leave a 1” stem on each fruit. Winter squash can be cured before storing, except for acorn squash. Why? The high temps and humidity of curing reduces the storage life of acorn squashes. Cure butternut, hubbard, spaghetti, delicata and other winter squashes in a warm well-ventilated area for ten days to harden the shell and heal any cuts (80-85% humidity is ideal). 

Store: Keep winter squashes (including acorn squash) stored in dark, well-ventilated areas that are 50-55 degrees and about 75% humidity. How long they last in storage depends on the variety.

  Four Storage Tips for Potatoes, Onions, and Winter Squash

  1. Give your stored veggies good air circulation. One of the best ways to do this is to NOT stack them. Moisture-rich root crops like onions and potatoes can spoil the entire harvest quickly if one starts to rot. 
  2. The best storage temperatures are between 45-55 degrees. (Below 60 degrees, but above freezing.)
  3. Don’t be tempted to store diseased veggies with your healthy ones. This is the quickest way to lose a whole season’s crop. 
  4. Avoid storing these vegetables near fruit. Ripening fruit produces ethylene gas which will make potatoes and squash over-ripen too quickly.

Remember – don’t let less-than-perfect temperatures or humidity stop you from storing your home-grown onions, potatoes, and winter squash. Your basement or a cool corner of the garage will do just fine. Here’s to delicious eating all winter long!

If you find this blog informative, consider donating to the Square Foot Gardening Foundation. Your support helps us to continue providing tips, resources and the mission of Square Foot Gardening.  

Chris McLaughlin

Chris McLaughlin is a writer and author of nine books on gardening and small livestock. Her primary focus is on regenerative gardening and wildlife habitats. Chris’ current project, The Good Garden: How to Nurture Pollinators, Soil, Native Wildlife, and Healthy Food - All in Your Own Backyard (Island Press). Chris lives on their small family farm in Northern California's Gold Country.

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