by Marilyn Odneal, Horticulture Adviser
(Mountain Grove) – Growing potatoes in grow bags and harvesting them right out of the sack is the easy way for sure. You don’t have to worry about damaging the spuds as you dig them from the ground. All you do is dump the bags and pick up potatoes! You still need to be gentle and not bruise the potatoes when you dump the bags.
I planted potatoes in bags in March. Since most potatoes take 100 to 120 days to mature, mine were ready to pick after the vines died down in July. However I did not get around to it once it began to rain almost every day – so I worried if the crop would be ruined. After all of the rain, however, the vines started growing again so I waited until August to harvest. Once the potatoes were harvested, only a few that had to be discarded. I also found that I had a crop of mature potatoes along with a crop of small “new” potatoes. I think the “new” potatoes were a result of the late flush of growth promoted by the heavy rains.
The potatoes were left outside on the tarp for about an hour. Then I put them in a dark part of the house on a couple layers of newspaper to cure for a while. Since mine was a small, early crop, I did not need to cure them for long storage. I let them sit on the newspapers for three days and then sorted the “new” potatoes from the mature ones.
Late potatoes are best to grow, harvest and cure for winter storage. Harvest potatoes for storage about two weeks after the vines die down in midsummer. Storage potatoes should have a curing period of one to two weeks to heal bruises. To cure, keep the tubers in a dark place with temperatures between 55° to 60° F with high humidity of 85 – 95 percent if possible. After curing, potatoes are best stored in cool, 40° to 50º F temperature and humid (85 – 95 percent) conditions for six to eight months in an area with adequate ventilation. A good way to keep potatoes for long storage is in wood or plastic boxes with slatted sides and bottoms for good air circulation. Also, fill the boxes only 6 to 8 inches high and store in a basement or root cellar. Sprouting can be a problem when potatoes are stored at higher temperatures.
So why do we keep our potatoes in the dark? When potatoes are exposed to light their skins start to turn green signaling that the toxic substance called solanine is developing. Solanine can be removed by peeling the green area off, so it is not a major problem. I am planning to grow a few more cultivars of potatoes in bags next year since it is so much fun harvesting them the easy way.
Please direct comments or questions concerning this column to Marilyn Odneal via email at MarilynOdneal@missouristate.edu; write to Missouri State Fruit Experiment Station, 9740 Red Spring Road, Mountain Grove, Mo. 65711; or call (417) 547-7500. Visit our Web site at http://mtngrv.missouristate.edu.