JoAnne Skelly: Don’t dig potatoes prematurely

I planted potatoes this year for the first time in a few years. I have been waiting for the plants to bloom, as that usually indicates it’s time to harvest new potatoes. However, my plants have never bloomed.

I found out that some varieties bloom late or not at all. To check whether there are new potatoes big enough to dig up, I will have to gently dig into the ground and feel around for them.

If you planted potatoes for storage and winter use, wait until the vines have died down and the potatoes are mature before digging them.

“If the skins on the tubers are thin and rub off easily, the crop is not fully mature and will not store well. Wait a few more days before harvesting,” said Richard Jauron from Iowa State University.

Mature potatoes have skin that is firmly attached. Frost encourages maturation. Potatoes should remain in the soil for about two weeks after the tops have died down. Don’t water at this time so the skins will set.

Avoid damaging potatoes you plan to store, although you can cook damaged potatoes right away. You don’t want any bruises, scrapes or cut surfaces, so be careful not to hit them with a shovel or fork when you dig. Once you have the potatoes out of the ground, they need to be cured at a temperature of 45 to 60 degrees and a humidity of 85 percent to 95 percent for two weeks. This allows minor cuts and bruises to callus and the skin to thicken. After curing, discard any soft or shriveled tubers because they are likely to rot in storage.

Store potatoes in the dark at 40 to 45 degrees. Potatoes will turn green if exposed to the light and sprout at temperatures higher than 45 degrees. When stored below 40 degrees, your potatoes may taste quite sugary. Leaving them at room temperature for a few days before cooking will restore the original flavor. The ideal storage humidity is 90 percent, which might be hard to achieve in Nevada. A cool garage may be the best option. Don’t store potatoes with apples or other fruits because the ethylene gas the fruits give off will cause potatoes to sprout.

JoAnne Skelly is the Carson City/Storey County Extension educator for the University of Nevada Cooperative Extension and may be reached at skellyj@unce.unr.edu.