Harvest potatoes after plants turn brown
Question: We grew potatoes for the first time this year. We didn't get to plant them until pretty late in the season, but the plants are now starting to die. Is it time to dig up the potatoes, or do we have to wait until the plants get frosted? Can we just keep them in the ground and dig them up as we want to use them, or do we have to take them all out at once?
Answer: Mature potatoes are typically ready to harvest two to three weeks after the plant's foliage has turned completely brown, but you can harvest young “new” potatoes soon after the plants come into flower. If you harvest these new potatoes from young plants, you'll need to eat them within a week or two of harvest, but if you allow the potatoes to sit in the ground for a few weeks after the vines die, the skins will cure and you can store the potatoes for several months.
Because it's so late in the season and your plants have already started to die back, your best option is to let the vines continue to brown for a few more weeks, even if they're subjected to a few frosts. The tubers will be snug under the soil, where their skins can continue to cure.
If possible, pick a dry day to harvest your spuds. Use a digging fork to gently pry up the plants, being careful not to stab any tubers. Make sure you get way down under the plant so you can lift the potatoes right up out of the soil. Then, dig through the loosened soil to find any remaining potatoes.
After you dig them up, eat any blemished tubers right away and store the rest for later use. Do not wash dug potatoes. Simply brush off any excess soil with your hands. Spread the harvested potatoes in a single layer in a dry, well-ventilated room for four or five days. Then, pack them into a cardboard box, plastic crate or basket.
Potatoes should be stored in a dark, cool room. Don't keep them in the fridge and don't allow them to freeze. A cool basement or dark garage would work, as long as they tubers are protected from light. The ideal storage temperature is 45 to 55 degrees.
If you decide not to dig them up, potatoes can be stored in the ground and dug as needed. But there's an increased risk of rot when you go this route. If we get a lot of rain in the early winter, or if the ground freezes solid, the tubers will rot. If you decide to keep them in the ground, mulch the area with a thick layer of straw after the plants die back completely. Potatoes stored in the ground also might fall victim to voles, mice and chipmunks.
Horticulturist Jessica Walliser co-hosts “The Organic Gardeners” at 7 a.m. Sundays on KDKA Radio with Doug Oster. She is the author of several gardening books, including “Attracting Beneficial Bugs to Your Garden: A Natural Approach to Pest Control” and “Good Bug, Bad Bug.” Her website is jessicawalliser.com. Send your gardening or landscaping questions to firstname.lastname@example.org.