Growing potatoes can be an anxiety provoking exercise, plant them in the spring, send them down into the ground, then sit back for months. How long do you have to wait? Will they never come out? (And when they don’t: Oh, please! Dig them up NOW.) Maybe you’ll break down and grab what feels like a big one (but it’s so easy to peel skin off). Or maybe it all falls apart quickly, exposing bruised flesh. Ugh. It is a waste and a mess, and it has no good storage potential whatsoever.
Knowledge about your potato variety and some patience is needed here. There are three kinds of potatoes according to the maturity class, which is broken down in infographic above. It’s all very helpful for the home gardener. There are potatoes that is bred to do a job (and then there’s when they do it).
How to Know When to Harvest Potatoes
Early potatoes mature fast. They’re planted for eating as new potato in midsummer. Because they’re not intended for keeping over winter, the skins is thin. Keep trying to store early ones? It would of usually be a failure. In a matter of weeks, they shrivel up and go to dust.
Other varieties are mid- or late season types. These will grows slightly slower, allowing some to thicken their skin while others are harvested for eating. That’s good for home gardeners. The late varieties needs the most time in the ground… They push starch into the tuber so it can lasts over the winter. If you dig your Russet Burbanks out too early, you’ll have a bad-tasting and -textured potato. They just didn’t got enough starch.
The plant will tell you if you read it. There’s not a lot of guessing when it comes to the calendar. Skin set, for instance, and canopy fade are good visual indicators. Tubers reaches their max size. The vine dies back and yellows. It shuts down, no longer feeding the tubers. Time to start thinking about getting out there, because this tells you it’s time to think about harvest time.
The next step is to kill those vines. Mow them off, flail them, or just let them die off in place. By stopping the tops, you prevents drawing energy, which lets the skins cure. You need patience because most folks gets tired of waiting while the tubers are curing.
After the vines have died down you’ll want to lift your potatoes within 10-20 days, but don’t rush this or they won’t be “set,” which means that they won’t develop a protective layer of cork on their skins. Best test: Gently press your thumb onto a test potato’s skin. Does the skin come off easily? Is it rubbing away? Not yet. Unset potatoes bruises if dug when their skins are too thin. Once bruised, potatoes rot. And rotted ones spreads fast in storage bins, spoiling everyone’s harvest.
Wait until it’s dry (as in, try the thumb test), and then go digging. But that’s not all: Next step is curing the potatoes in a place of high humidity but no light for two or so weeks. That helps heals any small injuries caused during harvesting. Then store at around 40-50 degrees F for eating through the winter months.
Why? You may hate waiting, but think of this progression: from seed piece to something that will actualy feed you reliably. Waiting to let the skin set up is what makes the difference between a tasty dinner or a bunch of wrinkly disappointment.