Unlike red sweet potatoes, red potatoes belong to the same nightshade (Solanaceae) family as white, russet, and every other regular potato variety. Sweet red potatoes belong to the morning glory (Convolvulaceae) family and have slightly red flesh. While they both have red skins, red potatoes have yellow, off-white, or white flesh.
Red potatoes have a lot in common with ordinary white and russet potatoes including when they are ready for harvest. A good rule of thumb for establishing when red potatoes are ready to harvest is to wait for the plants to die. When you see the foliage turn yellow, this is a reliable signal that the harvesting season for your potatoes is close.
How Do You Know When Your Red Potatoes Are Ready to Harvest?
Red potatoes, like other potatoes in the Solanaceae family, are a cool-weather crop. They take between about three and four months (anything from 75-135 days) to mature, depending on the variety. On average:
- Early season varieties reach maturity in 75-90 days
- Mid season varieties take 95-110 days
- Late season varieties take 120-135 days
Ultimately, it stands to reason that your red potatoes will be ready to harvest three to four months after you planted them. The best time to harvest them is on a dry, warm day.
The Texas University A&M AgriLife Extension advises digging them out of the ground when the soil is moist but not wet. When the soil is very dry, the clods of the earth may bruise the potatoes you are harvesting.
When to Harvest New Potatoes
If you want young, so-called new potatoes, you can harvest them as soon as they are large enough for your pot. This will usually be about 50 days after you have planted them when the flowers are still blooming.
When to Harvest Potatoes for Storage
Immature, new potatoes should be eaten as soon as possible after harvest. If you want to store your potatoes, you must allow them to fully mature.
The other factor is that the skin of your potatoes should be set. You can check this by rubbing the skin with your thumb. If the skin doesn’t come off, it is set.
As mentioned above, it takes three to four months for a mature potato crop to be ready to harvest. If you are planning to store your crop, let the potatoes grow for as long as possible.
The Michigan State University (MSU) Extension advises toughening up potatoes to be stored by not watering them much after they have flowered.
In any case, don’t dig the mature tubers out of the ground until two weeks after the vines have died. It doesn’t matter whether they are killed by frost or simply because they have stopped growing.
The Oregon State University (OSU) Extension Service points out that this will allow the red skins of the mature tubers to toughen. This, in turn, will make it less likely for the skins to be bruised or damaged when you harvest the potatoes.
What Happens If You Don’t Harvest Red Potatoes?
If you don’t harvest your red potatoes after your potato plants have died, there’s a good chance they will rot. If you live in a cool climate, frost may kill them.
If some potatoes are left in the ground, pull them up when they sprout in spring. Generally, potatoes that have been left in the ground will be tough and may even be diseased.
How to Harvest Red Potatoes?
We sometimes plant potatoes in raised beds or in a hill surrounded by a shallow trench about four inches (10 cm) deep. Alternatively, it’s possible to cover the growing plants with mulch, like straw.
If you have opted for mulch, you can remove the mulch once the foliage has died when it comes to harvesting potatoes. This makes the process simpler.
Otherwise, you will need to use a pitchfork or shovel to dig your red potatoes out of the ground.
Like white potatoes, red potatoes have quite thin skin, so keep your spade or fork about eight to 10 inches (20-25 cm) away from the tubers. Then raise the potatoes and pull them out of the ground.
If you damage any of them, cook them as soon as you can.
Should You Wash Red Potatoes after Harvesting?
If you are going to eat your red potatoes soon after harvesting, you should wash them. But never wash potatoes that you are going to store unless your soil is a sticky clay type.
Wet potatoes will decay very easily, and there is no practical reason to wash them. You should, though, clean them by brushing off the dirt before you store them.
The OSU Extension Service advises that potatoes grown in fine, sticky clay might need washing. If you do wash them, you must be 100% sure that they are completely dry before you store them.
Can You Eat Red Potatoes Immediately after Harvesting?
Yes, you can eat red potatoes immediately after harvesting. In fact, if you are harvesting potatoes that are immature (either new potatoes or small to medium potatoes that aren’t fully grown), you must eat them very soon after harvesting.
If you aren’t going to eat your red potatoes immediately or soon after harvesting them, you will need to store them correctly.
Storing Red Potatoes
Some stored potatoes will last for seven to eight months in the right conditions.
Red potatoes won’t last this long in storage. But if you have a big crop of mature potato plants, it’s a good idea to store at least some of them for the winter months.
Thick-skinned varieties like russets will last a lot longer than thin-skinned white and red potatoes. Also, early maturing red potatoes won’t store and mature later in the season.
Before storing red potatoes long-term, sort them and remove any that aren’t 100% healthy. Put all the decent potatoes into well-ventilated containers in a cool, dark environment like a basement or garage.
Low storage temperatures under 45°F (7°C) will often sweeten mature tubers. High temperatures, on the other hand, will result in rot, shriveling, and unwanted sprouting.
Light leads to the development of chlorophyll, which will turn a mature potato green. Although it is harmless, it often combines with high levels of a toxic alkaloid called solanine, which contains high amounts of nitrogen.
Red potatoes are a staple crop that you can eat immediately after harvesting or store for several months to keep you going for the winter months.
Our gardening tips contain loads of advice that will help you harvest your mature potato crop at the right time. They also walk you through the harvest process, to ensure that you maximize the fruits of your labor.