Is It Time to Harvest Those Potatoes Yet?

If you're not a big fan of surprises or suspense, then growing plants that produce underground might be more stressful than exciting. Potatoes have all the mystery of radishes and carrots, only you have to wait so much longer to harvest them.

By the time you get to stick your pitchfork in the soil and dig up some spuds, it'll feel like that moment in the game of hide-and-seek when you're about to pull back the shower curtain, unsure of what will be on the other side. You'll have no idea what's been growing (or not growing) under the ground all these months.

Fortunately, potato plants give us some really obvious signs that they're ready to be harvested. Whether or not you'll be harvesting the tubers of your dreams or some shriveled-up roots, well, that's a different story.

Here are three signs your potato plants are ready to be dug up and reveal to you the hidden treasure they've been guarding all summer.

How Long Do Potatoes Grow Before Harvesting? 

Most potato varieties need about 90 to 120 days to reach maturity and be ready for harvest, though some, like Yukon gold, can be ready in as few as 75 days. Other varieties, like the russet potato that gives us our beloved baked potatoes, can take up to 135 days. In the gardening world and in life, good things take time, you know?

If you’re feeling impatient, remind yourself that potato plants have to grow underground and above-ground stems. Then they have to form half a dozen exact copies of themselves at the edge of those underground stems. I mean, imagine if humans could clone themselves from their fingertips—that would definitely not be a fast process!

You’re Nearing the Days to Harvest for the Type of Potato You’re Growing

Check the growing information from the company you purchased your seed potatoes from. They should tell you the time to harvest for the variety you’re growing. Since different potato types can take a whole month longer than others, it's a good idea to have at least an idea. Keep in mind, however, that this time assumes your potatoes have been grown under ideal conditions. 

Count forward from the time of planting based on the number of days till harvest. When you’re nearing the anticipated harvest time for the type of potatoes you’re growing, start checking for the next two signs. 

The Potato Leaves Turn Brown and Papery

A change in color of the leaves on your plant is a telltale sign that the plant is nearing the time when your buried treasures can be dug up.  

When all those spuds have formed underground, the leaves of the potato plant will begin to turn brown, dry out, and die. Pale, papery leaves are certainly not going to do any more photosynthesis or grow larger. You’ll also notice the leaves are dropping toward the ground. Once the leaves are lying down on the job, your plant is done. Wait for the foliage to fully die back before harvesting.

If your leaves are starting to lose their bright color, lean over, and become dry to the touch, you’re probably a couple weeks away from harvest. Your potatoes are finishing up. Now is a great time to stop watering your plants so that the tubers can begin to toughen up a bit before harvest. 

If the foliage on your plant is still nice and bright green and upright like in the picture below, then you won’t be harvesting your potatoes anytime soon.

The Potato Skins Are Thick and Firm

The great thing about a crop like potatoes is that you can dig a couple up, check them for readiness, and cover them right back up with dirt if they’re not ready. 

If the plants are in the ground, you’ll need a pitchfork or large shovel to harvest your first set of potatoes. If they’re growing in a container, barrel, or grow bag, you can probably just use your hands to pull them up, especially if the plant is still intact. 

Do a little inspection of the first spuds. A mature potato has thick, firm flesh. If the skins feel too delicate and can be easily rubbed off with your thumb, those potatoes are not finished. While you can go ahead and harvest these little guys (they’re considered “new potatoes”), you won’t cure them and should eat them as soon as possible. Root crops with delicate skins are not storage material. It’s a good idea instead to leave the rest of the potatoes in the ground for a while longer. 

Actual potato size is not a good indication of the plant’s maturity. Some spuds might not be as large as you’d like, but if the plant is dead, they’re done growing and need to be harvested within a week or two.

When Do You Harvest "New Potatoes"?

Baby or "new potatoes" are harvested once the tubers have formed but before they've grown to their full size and hardened their skins. Look for your potato plant to form flowers. That's a good indication that there are lots of little spuds underground. Be extra careful when harvesting and handling these babies. The qualities that make them so tender and creamy also make them fragile, so enjoy them as soon as possible rather than trying to store them.

Should You Harvest All of Your Potatoes If Frost Is Coming?

If frost is in the forecast, go ahead and harvest your potatoes before the freeze hits. Even if the leaves haven’t fully dried up yet, grab your pitchfork and start digging. You might end up with a lot of baby potatoes that need to be enjoyed sooner rather than later.

How Many Potatoes Does Each Plant Produce?

Each tuber piece or seed potato you planted will now be attached to more tubers via its underground stems. You can expect at least five to six new potatoes for each potato you planted. If only every plant multiplied this way!

Why Do You Have to Stop Watering a Potato Plant Before Harvest?

You need to let the ground and the potatoes themselves dry a bit and do what's called "setting" their skin before harvest. If you skip this part, you could end up harvesting a too-wet tuber that will only end up molding in storage. You also want to wait for a day when the ground is dry to harvest.

What's the Best Way to Harvest Potatoes?

We've got a whole post about how to harvest and cure potatoes.

It's Potato Harvest Time!

Grab your pitchforks, folks! Digging up potatoes after waiting for three or more months for them to grow is one of the most delightful (and maybe a little suspenseful) things you can do in the garden. Grab your kids, grab your camera—it's gonna be the best type of treasure hunt in your own backyard!