How large can a potato be?

Select loose potatoes that are well formed, smooth, firm, with eyes, and no discoloration, cracks, bruises or soft spots. Red potatoes and some whites are sometimes treated with colored or clear wax to make them appear fresher than they are. Also avoid “green” potatoes. They have been exposed to light and have a bitter taste.

Potatoes are classified by shape, skin color and use. The long brownish ones are good for a variety of uses but are best for baking. Rounded or long whites are preferred for boiling and baking, and the small red ones are ideal for boiling. “New” potatoes, the small ones that are dug early before the skins have set, are best boiled or steamed.

The potato (Solanum tuberosum) is an herbaceous annual that grows up to 100 cm (40 inches) tall. As the potato plant grows, its compound leaves manufacture starch that is transferred to the ends of its underground stems (or stolons). The stems thicken to form a few or as many as 20 tubers close to the soil surface. The number of tubers that actually reach maturity depends on available moisture and soil nutrients. Tubers may vary in shape and size, and normally weigh up to 300 g (10.5 oz) each.

At the end of the growing season, the plant’s leaves and stems die down to the soil level and its new tubers detach from their stolons. The tubers then serve as a nutrient store that allows the plant to survive the cold and later regrow and reproduce. Each tuber has from two to as many as 10 buds (or “eyes”), arranged in a spiral pattern around its surface. The buds generate shoots that grow into new plants when conditions are again favorable.

Want to grow your own tasty spuds? You can, right in your own backyard! Here are the things you need to know to get a bumper crop this summer.

by Amber Kanuckel Updated: November 7, 2022

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Want to grow your own tasty spuds? You can grow all kinds of potatoes—russet, white, red, yellow, and even purple potatoes—right in your own backyard. And you don’t need a lot of space—you can grow them in bags and burlap sacks! Here are the things you’ll need to know to get a bumper crop this summer!

Whether you’re planting in a garden bed or bag, follow these easy steps.

Start With Seed Potatoes

Seed potatoes generally come in two different sizes: small, which are tubers that are between one and two inches in diameter, and large, which is anything over two inches. Small tubers can be planted directly—don’t worry about cutting them up.

If you purchase large seed potatoes, then you’ll need to cut them down to about the same size as a small seed potato. Cut them in half, or if the potatoes are really large, cut them into quarters. Make sure that each chunk of potato has at least one eye, which is a small depression in the surface of the potato where the roots sprout. If you need to cut seed potatoes, it is best to wait at least four to seven days before planting them. Let the cut surfaces “heal” in a cool, dry place to reduce the risk of your seed potatoes rotting.

When Should You Plant Potatoes?

Timing is important—both for the potatoes themselves and the soil temperature. If you wait too long before planting the seed potatoes, you may have trouble getting them to grow. How long is too long? Seed potatoes will grow well if the sprouts growing from the eyes are no more than 1/2-inch long. In other words, if there are no sprouts or short sprouts, then you are good to go. To prevent your seed potatoes from sprouting, keep them in a cool, dry and dark place away from other fruits and vegetables.

Potatoes like cool weather, so time your planting for when temperatures are right around 55 degrees at night. The soil temperature should be cool, but not freezing — 45 degrees is ideal.

Check out our Gardening by the Moon calendar for the Best Days to plant here.

Choosing the Right Soil

The key to planting potatoes is choosing the right soil. Soil shouldn’t be heavy or wet because the potatoes may rot, but it also shouldn’t be too dry because that will slow growth. Choose a location with moist, but not soggy soil—or use a potato growing box (there are many tutorials on how to build them online, see below) so that you can better control moisture throughout the growing season.

When it comes to planting in containers, it’s best not to use plain garden soil only in your container as it is too dense and will compact. It’s best to use a good potting mix, which you can find in 40 bags at most garden centers. A good mixture is 1/3 garden soil, 1/3 soilless potting mix, and 1/3 finished compost. 

Eyes Up!

Seed potatoes should be planted between three and four inches deep, spaced between nine and 12 inches apart, with the sprouts, or eyes, facing up. The farther apart you space each seed potato, the larger the tubers can grow.

Caring for Your Potato Plants

To keep your potato plants growing strong all summer, there are a few things that you should do. First, once the potato plants have grown to roughly 12 inches in height, you should mound soil around the base, calling “hilling,” to help protect growing tubers. Mound the soil up to 6 inches in height, out to 15 inches from the base of the plant.

You can also mulch your potatoes with straw to a depth of between four and six inches. This does two things: It helps keep weeds down, and it helps to keep the ground cool and moist throughout the summer.

Finally, you’ll need to keep an eye out for pests and diseases. To avoid bacterial or fungal disease, it is best to plant your potatoes in a new spot each year. The potato beetle is a common pest, but you can prevent an infestation by inspecting the undersides of potato leaves for eggs. If you spot a yellow to orange cluster of eggs, remove the affected leaves.

Harvesting Your Spuds

If you like “new potatoes,” then you can start harvesting within two to three months of planting, although most gardeners will only harvest a small portion of their crop while allowing the rest of the potatoes to keep growing. To harvest larger potatoes, find out what the recommended growing time is for the variety you chose—usually between 70 and 100 days. When the time is right, cut the potato plants back to the ground, water them one last time, and then wait two weeks to let the potatoes age and the skins toughen up — in the ground.

Harvesting your potatoes is easy. If they’re in a plot of soil in the garden, gently turn the soil with a spade or potato fork and pick up the potatoes you find. Brush off the dirt on each potato, then allow them to cure for another week or two in a cool, dry place. In containers, many potato bags have “windows” to access the tubers. If you’re harvesting new potatoes, they don’t need to be cured.

Remember: Potato plants (the green parts) are poisonous and are not to be ingested.

For added gardening success, be sure you check out our Best Days calendar here to pick the right day to plant potatoes.

Tips for storing potatoes.

Grow Potatoes In A Burlap Bag!

Potatoes can be grown in any number of different style planters. Bags are very popular. Check out this clever method of growing them right in burlap sacks!

About the author Related Posts

Amber Kanuckel

Amber Kanuckel is a freelance writer from rural Ohio who loves all things outdoors. She specializes in home, garden, environmental, and green living topics.

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