When growing vegetables in your garden beds, there’s nothing like the taste of fresh potatoes, but every new gardener has the same question: “When are potatoes ready to dig up?”
It isn’t a stupid question as you can’t see underground, yet harvesting at the right time means you can skip the high grocery store prices.
You can grow three different potatoes in a regular growing season. First earlies, second earlies, and maincrop are the three varieties.
New potatoes refer to the first and second early cultivars. They have a shorter growing season and are often smaller than maincrop, but they taste better. (Read Growing Potatoes Indoors Guide)
When the potatoes reach the desired size, you can harvest them. Depending on the temperature and the potato variety, “new” potatoes are usually ready 60-90 days after planting.
In our guide, you can learn how to tell when are potatoes ready to pick. By the end, you’ll know when do you harvest potatoes to get the fresh-tasting smaller ones or the larger type you can store for longer.
Do Potatoes Have to Flower Before Harvesting?
If your potato plants don’t have any potato flowers, don’t worry. Potato flowers aren’t required for the plants to produce tasty tubers underground. The blooms are linked to the production of small, green above-ground fruits that look like tomatoes.
Once the canopy flowers have blossomed, normally six to eight weeks after the potato plants develop, you can harvest “new” potatoes.
The diameter of these young potatoes ranges from one to two inches. Gently dig near the plants and remove a few tubers from each plant.
Then, cover the opening to allow the remaining tubers to mature. Harvesting a few new potatoes without destroying the plant is simple when you plant in straw.
Remove a few potatoes from directly underneath the straw layer, then reapply the straw layer.
Because the thin, immature skins of early varieties allow rapid moisture loss and disease viruses to infect them more easily and use new potatoes as quickly as possible after harvest.
New potatoes can be stored in the refrigerator for up to one week after being harvested. While tubers mature underground, new potatoes can be harvested continuously. (Read Can You Eat Potatoes That Have Sprouted)
Harvesting Main Crop Potatoes
Harvest potatoes when they are fully mature if you plan to store them for the fall and winter. Harvesting mature potatoes might take anywhere from 70 to 120 days, depending on the cultivar. The tubers have attained maturity when the stem and leaves of the potato plant turn yellow or brown.
When the tops of your potato plants die back, stop irrigating them. Pruning shears can clip the plant tops off at the soil surface level to promote wound healing and tuber maturity. In areas where potato harvesting is hampered by damp fall weather, this is a beneficial practice.
About two weeks after the vines have perished or been trimmed back, dig your potatoes. Irrigating the potato crop lightly before digging softens soil clods and lowers the risk of bruising and tuber damage during harvest.
To find the potatoes, carefully dig around the plants using a garden “lifting” fork. To draw out the potatoes, push the fork into the soil just outside the row and lift it under the potato plant.
When you dig up fully matured potatoes, you’ll see that the skin has hardened and is tough to remove. (Learn How To Plant Seed Potatoes)
Potatoes dug from warm soil (50°F to 65°F) are less likely to bruise than those pulled from cold soil (45°F or lower). Desiccants can be used in commercial settings to dry potato vines, yet rarely used in the home garden.
Potato Harvesting Tips
Here are some quick tips to make potato picking easier:
- Potato tubers can be harvested at any stage. New potatoes are harvested before they are fully matured, and harvesting can lead to more potatoes forming.
- The skins of potatoes stiffen as they mature older, and when rubbing a new potato, the skin easily peels away.
- A potato plant yields 3 to 6 regular-sized potatoes and many little potatoes.
- Digging maincrop potatoes using a spading fork is recommended. To avoid bruising or injuring the skins, gently lift the potatoes and harvest potatoes with your fingers.
- Although potatoes can be left in the ground as a fall crop, wait until the first frost, as they are most nutritious when harvested as mature tubers.
- Protect harvested potatoes from the sun; as exposed potatoes turn green and produce solanine, a bitter taste and can be harmful if eaten in quantity.
- Before storing potatoes, allow them to cure by placing tubers in a single layer at 50°F to 60°F in a dark place for two weeks.
- Potatoes should be kept at a temperature of around 40 degrees Fahrenheit.
- Save some of your best tubers for next season’s seed potatoes. Soft or discolored potatoes should not be saved, as any infected plants shouldn’t be saved.
- Rather than keeping your potatoes as seed potatoes, you can get certified seed potatoes. To get the best results, cut seed potatoes to have two eyes on each piece and then get planting.
- Potato seeds or eyes on your potatoes can be knocked off, yet it is better not to eat them, and you can use them as a seed potato.
How Long After Potatoes Flower Are They Ready?
When you do harvest, you’ll be astonished at how tasty the humble potato can be. Dark green leaves grow and are crowned by clusters of little white flowers with golden centers around two months after planting.
You’ll be rewarded with a fresh potato far superior to anything you’ll find from the store potatoes you can buy from the supermarket. Remember, sweet potatoes are not related and won’t be affected by the conditions.
As potatoes reach the desired size, you can harvest them. Depending on the weather and the potato variety, “new” potatoes can be ready for harvest 60 to 90 days after planting.
The emergence of flowers on the planted potatoes is a good sign the immature potatoes are ready. (Learn How To Store Potatoes After Harvest)
About 120 days after you plant potatoes, you’ll find potatoes ready to carefully dig up.
What Happens If You Harvest Potatoes Too Early?
When the foliage dies back, regular potatoes are ready to harvest. Before you harvest, the plants’ tops must be fully dead.
2 to 3 weeks after the plants stop flowering, “new potatoes,” which are potatoes harvested early for their smaller size and sensitive skin, will be ready to harvest. New potatoes should not be cured and consumed within a few days of harvest since they do not keep for long.
By not watering potatoes much after mid-August, you can toughen up for storage before you harvest mature potatoes.
Potatoes may tolerate light frost, but when the first strong frost is predicted, it’s time to start potatoes with shovels.
Leave the potatoes for 10-14 days before harvesting the brown foliage. To get a thick enough skin on the potatoes. Wait too long, and the potatoes will rot in moisture-laden soil.
A dry day digs potatoes. Gently dig up, not damaging the tubers. Cut or bruise potato skin. Damaged potatoes rot in storage and should be used immediately. Digging should be easy due to loose soil.
If the soil is soaked, let the potatoes dry completely before storing them.
If you leave your harvest potatoes in the sun for too long, they turn green. Green potatoes are bitter and contain solanine, which can cause vomiting and diarrhea if eaten in excess. Small spots can be trimmed, but large green spots should be discarded.
Keep potatoes in a dry, cool, dark place (45-60°F/ 7-15°C) for up to two weeks. This allows their skins to cure, extending their shelf life.
After curing, brush off any soil that clings to the potatoes.
Wash potatoes right before using them, whether you dig them yourself or buy them. Only do it here, as washing potatoes reduces storage life.
After curing, do not store potatoes near apples; the ethylene gas from the apples will cause potatoes to spoil.
Potatoes are a cool-weather crop. They are grown in temperate, subtropical, and tropical climates. The life cycle of your potato crop depends on your climate.
For example, in a USDA Zone 6a area, white potatoes mature in 135 days.
- Early potatoes need 60-100 cool days to mature, and early potatoes are best for hot summers in the south.
- Mid-season potatoes take 101 to 135 cool days. These varieties need 135-160 cool days to mature.
- Late-season potatoes are ideal for northern regions with mild summers.
The minimum and maximum temperatures in your area, as well as the potato varieties you select to plant, will be the major factors in growing potatoes. In temperate zones, you start growing potatoes in early spring, while in warmer regions, they are sown in late winter. Homegrown potatoes grow best in cooler months of the year in tropical regions.
When planting potatoes in some subtropical highlands with mild temperatures, you can grow potatoes all year round. Such areas comprise central Europe, coastal northwestern North America, South America, and other regions.
Mature storage potatoes can mature in 90 days when grown under optimum conditions (60° to 70°F). However, you can be ready for freshly dug potatoes up to 150 days from planting in milder temperate settings.
Depending on your garden’s availability to light and soil conditions, planted red potatoes will reach different days to mature. You need to select a planting cycle and a potato variety that matures in your garden between 80 and not below 40 degrees Fahrenheit.
What Do Potato Leaves Look Like When Ready to Harvest?
Toughen up potatoes for storage before harvest by not watering them much after they flower. Let the potato plants and the weather tell you when to harvest them. Wait until the tops of the vines have completely died before you harvest.
Leaving potatoes until the vines are dead is a sign the potatoes have finished growing and are ready to be harvested. Potatoes are tubers, and you want your plant to store as much of that flavorful starch as possible.
By avoiding watering potatoes much after they flower, you can toughen them up for storage before harvest. Allow the weather and the potato plants to tell you when to harvest them. Before you harvest, wait until the vines’ tops have totally perished.
When the vines die, it means the potatoes have reached the end of their growth cycle, and you are ready to harvested potatoes. Maincrop potatoes are tubers, and you want your plant to store as much delicious starch as possible. (Learn How To Grow Sweet Potato)
To determine how mature the raw potatoes are, dig potatoes up in a test hill. Potato skins are thick and firmly adhered to the flesh of mature potatoes. New potato skins can be rubbed off easily and take a few more days before you can harvest potatoes.
If you leave any potato varieties in the sun for too long after they’ve been dug up from your garden, they’ll turn green. Avoid eating green potatoes as they have a harsh taste and can cause vomiting and diarrhea if consumed in large quantities. Small patches of greening can be cut away, but they should be discarded if the potato is significantly greened.
Potatoes may withstand light frost, but when the first strong frost is predicted, it’s time to start potatoes with shovels. Be careful not to scratch, bruise, or cut the potatoes as you dig since damaged potatoes rot if left in storage, so use them as soon as possible.
Your own potatoes must be cured on harvesting, so keep them two weeks at temperatures ranging from 45 to 60 degrees Fahrenheit. This will allow the skins to harden and small wounds to heal. Be sure to check it isn’t potato scab, as this could affect all the potatoes in your root cellar.
- After harvesting, store potatoes in a cool, dark place as grown potatoes will turn green when exposed to too much light.
- To keep the potatoes from becoming green, cover them with soil, or you can harvest your new potatoes, which are baby potatoes that range in size from 1 to 2 inches in diameter.
Remember, when you start digging potatoes at this age because the small potatoes taste so good with their tender skin, you’ll have fewer storage potatoes later in the season.