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Harvesting potatoes

As summer is sliding towards fall it means we can likely harvest our potato crop soon. Most gardeners have likely been enjoying munching on new potatoes from the garden to enhance summer barbecues.
potatoes
With proper storage, a potato crop will keep well into late winter. Photo by Patricia Hanbidge

As summer is sliding towards fall it means we can likely harvest our potato crop soon. Most gardeners have likely been enjoying munching on new potatoes from the garden to enhance summer barbecues. This year, yet again, my potatoes were planted well into June.

For those serious gardeners out there who grow potatoes like my grandfather did, you have a big job ahead of you. My grandfather, who farmed, had a philosophy that you will never go hungry if you plant lots of potatoes. That thought conjures up the Irish potato famine, so let us instead talk about how to best harvest those staples in our diets.

One of the common questions asked about this time of year is: "Should I chop off the tops of my potato vines?" In answer, I first asked if her potatoes were ready to harvest. I shared that the leaves of any plant are like the factory that produces food, so without the leaves, there is no food produced and the potatoes will no longer grow. So, keeping that in mind, harvest your potatoes after the vines have been frozen or dried up.

When you are ready to harvest, wait for a warm, dry day, preferably after several days without rain. It is not a pleasant task to dig potatoes in muddy soil. Use a potato fork with flat tines if you have one as you will damage fewer potatoes by spearing them while digging. Dig well outside of where the vine grew to determine the expanse of the wealth of potatoes underground.

If you do damage a potato or two, ensure that those potatoes get eaten in the near future and are not put into storage. To ensure good storage, potatoes need to be cured before storing. Curing allows the skin to thicken and form a protective layer to the inside. Minor cuts and bruises will heal during this curing process.

Spread the potatoes on a flat dry surface for three to five days or until they are thoroughly dry. Some people like to wash the potatoes at this stage but even wearing a pair of gloves the dried soil that might still adhere to the potato will easily rub off. When it comes to storage, think cool and dark with good air circulation. Potatoes are not dead - they still are respirating, which is a process that gives off moisture and heat. Therefore, the air circulation is essential to prevent rotting.

Bins with slatted wooden floors, raised off the floor, and with slatted sides provide for air movement. Pile potatoes no deeper than eight to 12 inches. Potatoes store best at temperatures of 4-10 C, with a relatively high humidity. Warmer temperatures encourage sprouting and as the potatoes sprout, they will shrivel. Above 7 C, the starches in the potatoes change to sugar and the potatoes will turn dark when cooked. Too much light exposure, either in the garden or in storage, turns potatoes green. The green area contains solanine, which tastes bitter and can cause illness. When preparing potatoes for use, cut away and discard any green areas. 

 As you move your crop into storage, look for and remove any that are blemished, shriveled or soft. If possible, check every few weeks for any signs of spoilage. Rotten potatoes stink, and one rotting potato quickly becomes three and four rotting potatoes. If you can come close to meeting the storage needs of "this living breathing organism named potato,” as someone has described it, you will have potatoes from your garden until well into late winter.

— Hanbidge is a horticulturist with the Saskatoon School of Horticulture and can be reached at 306-931-GROW(4769); by email at growyourfuture@gmail.com or check out our website at www.saskhort.com.