You cure potatoes after digging by placing them in a dark spot at 50 to 65°F (10 to 18°C) with high humidity for 10 to 14 days. This waiting period lets the skins toughen up and any nicks from harvest heal over. Proper curing can double or triple how long your potatoes last in storage.
I set up a curing station in my basement every fall. I use large cardboard boxes lined with newspaper. A simple thermometer hung on the wall helps me track the curing temperature potatoes need to heal well. I drape damp burlap sacks over the top of each box to keep the air moist. The whole setup costs almost nothing but makes a huge difference in my storage success.
The potato curing process works because of the same chemistry that toughens skins before harvest. When you dig potatoes, you nick and scrape some of them no matter how careful you are. These small wounds let moisture escape and invite rot organisms inside. During curing, the tubers form new layers of suberin over these damaged spots. This waxy coating seals the wounds and protects the potato.
Iowa State research spells out the ideal conditions clearly. Cure at 50 to 60°F (10 to 15°C) with 85 to 90% humidity for about two weeks. The temperature range matters because it's warm enough for the healing process to work but cool enough to prevent sprouting. The high humidity keeps tubers from drying out while their skins set.
Don't wash your potatoes before curing. I know it's tempting to clean off all that dirt. But the water promotes rot instead of healing. Just brush off the loose soil with your hands or a soft brush. Leave some dirt on the skins if it's stuck there. You can wash the potatoes later when you're ready to cook them.
Find the right spot in your home for curing. A basement works great in most climates. A garage can work in fall when temperatures drop. An unheated spare room or closet might do the job. The key factors are darkness, moderate cool temps, and decent moisture in the air. Avoid spots that get too warm or too dry.
I learned the hard way what happens when you skip curing. My first year growing potatoes, I washed them all and put them straight into bins in my cold cellar. By Christmas, half had soft spots or mold. The tubers I had nicked during harvest rotted first. Those small wounds needed time to heal but I never gave them the chance.
Check on your potatoes a few times during the curing period. Remove any that show signs of rot or soft spots. One bad tuber can spread decay to the ones touching it. Keep the burlap or covering material damp but not dripping. Add a spray of water if things feel too dry.
After two weeks, move your cured potatoes to long-term storage. The curing temperature potatoes needed for healing is warmer than the cold temps needed for storage. Drop them down to 35 to 40°F (2 to 4°C) for the best keeping. Your properly cured crop can now last four to six months or even longer.
The potato curing process takes patience but pays off big. Those two weeks of waiting let your harvest heal up and prepare for the long haul. Rush this step and you lose potatoes to rot all winter long.
Read the full article: When to Harvest Potatoes: 6 Key Signs
