Precise practices preserve produce

Storage methods cater to differing traits

Ray Mueller
Jan Erdman

CUSTER – Careful attention to storage practices for root crops and other vegetables can preserve their quality and extend their edibility for many months, experienced gardeners Larisa Walk of Winona, MN, and Jan Erdman of Menomonie told attendees at the 2017 Energy Fair.

The two women shared differing practices on how they handle certain items but they agreed on the importance of knowing the traits on how various vegetables and fruits handle storage.

Erdman said she is motivated by the idea of storage methods because it means less work at the time of harvest and less canning of the produce.

A practice that Walk has discovered is using insulated picnic coolers once the summer is over for storing vegetables such as beets, carrots, cabbage, kohlrabi, and potatoes – each of which should be in a separate container.

Walk cited the ease of moving the coolers to new places at the appropriate temperature as the weather changes and pointed out how the coolers buffer temperature and humidity extremes. She also has a root cellar that was constructed under a sun porch.

Staying alive

Once certain species are removed from the garden, they want to remain alive in storage, Erdman and Walk pointed out. This applies to root crops and tubers along with leafy cole crops and the biennials such as carrots and parsnips which produce seed in a second year of growth, they explained.

With carrots, Erdman processes those of poor quality and prepares the remainder for longer term storage. In order to maintain the cleanliness of her facilities, she washes the soil from her carrots with a hose, trims the top one inch, dries them, and then stores them in plastic bags.

Larisa Walk

Walk partially washes the carrots dug from her clay soil, does not trim the tops, and dries them for storage with the help of sawdust. She said it is important to chose the carrot varieties which are suitable for long term storage.

Additional hints

One cardinal rule of storage is to avoid having apples and potatoes close to another, Walk and Erdman pointed out. That's because apples, along with tomatoes, honeydew melons, peaches, plums, cantaloupes, and pears emit an ethylene to which potatoes, summer squash, zucchini, cucumbers, and beans are sensitive.

With awareness of the storage life of differing varieties of apples, Walk likes to use the coolers for storage. She finds that putting layers of newspapers between the apples is a good practice.

For potatoes, Erdman chooses plastic bins (not wood ones) and Walk uses milk carton crates, making sure the storage site temperature is not below 45 degrees.

While those foods thrive on high humidity in storage, lower humidity is appropriate for onions and garlic, the presenters noted. Walk pointed out that onion storage varies with the variety, meaning that the Vidalia is not a candidate for long term storage. Both need to be cure dried before being put in a dark place with 60 to 70 percent humidity.

Dried shelled beans also enjoy the dark in sealed jars.

Season extenders

In addition to enhancing the storage window by harvesting as late as possible, Walk and Erdman cited the possibility of harvesting root crops such as carrots, turnips, and parsnips throughout the winter if they are covered to prevent freezing of the soil.

With a bit of covering during the winter, spinach plants can survive the winter and provide fresh greens early in the spring, Walk pointed out.

Erdman mentioned the harvesting of kale in November and December in most years. While noting it's a risky practice, she cited one success with planting peas in August.

Walk advised growing pea sprouts indoors and harvesting them throughout the winter as fresh produce.

Plant growth will virtually cease when there are less than 10 hours of sunlight per day but there are ways to keep species such as lettuce alive during those times, the presenters indicated. They explained each added layer of protection such as a cold frame unit, a blanket, plastic row cover, low tunnel building, or hoop house in effect adds one growing zone to the possibilities at a given site.

Walk provides insights on a “four season pantry” on her website. She can be reached by e-mail to