If you're accustomed to purchasing your potatoes (Solanum tuberosum) from the grocery store, chances are you've only tasted a few common varieties. This starchy, round vegetable is a popular addition to meals in many countries, as it is easy to grow and can be prepared in a large variety of recipes. When you grow your own, you can also discover a whole world of flavors, colors, shapes, and sizes you may not be familiar with yet. With hundreds of potato varieties readily available for home gardeners to choose from, growing organic potatoes can help spruce up the ingredients in your kitchen with little effort compared to many other home-grown foods.
It takes about three to four months for potato plants to reach maturity, depending on the specific variety (some small potatoes can be harvested in just under two months). In southern states, seed potatoes are usually planted in the fall or winter, but those in northern climates should wait until right before the last frost of spring.
Potatoes have long been a staple ingredient of diets around the world, as they contain important nutrients like vitamin C, potassium, and vitamin B6. Like other plants in the nightshade (Solanum) family, potatoes contain glycoalkaloids that can become toxic to humans and pets when the plant is no longer fresh—so be sure to eat this vegetable while it's ripe. The leaves, stems, and skin have the highest concentration, meaning a spoiled potato with green skin is likely unsafe to eat.
|Common Name||Potato, Irish potato|
|Botanical Name||Solanum tuberosum|
|Plant Type||Annual, Vegetable|
|Size||1.5-3 ft. tall, 1.5-3 ft. wide|
|Sun Exposure||Full sun|
|Soil pH||Acidic (5.0 to 6.0)|
|Hardiness Zones||3-10 (USDA)|
|Native Area||South America|
|Toxicity||Leaves, vines, green skin are toxic|
How to Plant Potatoes
When to Plant
You should only plant certified disease-free seed potatoes, which are available in garden centers, nurseries, and catalogs (potatoes from the grocery store may be treated with a growth inhibitor). Some varieties of potatoes take longer to harvest than others: Early-season variants typically take about 60 days to reach maturity, while late-season variants can take more than 90 days. In northern regions, choose a planting time based on your potato variety and the average time of your area's last frost.
Cold-climate gardeners should typically plant potatoes in the spring once soil temperatures have consistently reached 40-50 degrees Fahrenheit. If you live in a warm climate, it's best to plant your potatoes in late summer or late winter: This helps to avoid the year's warmest temperatures during their growth. To continue harvesting over a longer period of time, you can plant both early- and late-season variants at the same time.
For an extra early start on early-season varieties, you can "chit" them. This simply means laying your tubers eye side up in a box in a cool, dry place for one to two weeks until the eyes sprout. You do not need to chit mid- and late-season potatoes; simply plant the tubers whenever you're ready.
Selecting a Planting Site
Potatoes should be grown in an area that gets at least six hours of sun per day in healthy soil that is acidic and well-drained. Heavy clay soils make it difficult for full-size tubers to form. The planting site should also be a spot in which you have not grown potatoes, tomatoes, peppers, or eggplants for the past two years to prevent the transmission of soil-borne diseases from other plants in the nightshade family.
Spacing, Depth, and Support
Small seed potatoes can be planted whole. Those larger than a chicken egg can be cut to retain one to three eyes per piece (though this isn't essential). Make sure that you let any cut seed potatoes sit out for at least 24 hours before planting so the cut sides can callous over and won't rot.
There are several methods for planting potatoes with various guidelines:
- Trench-and-hill method: Dig a trench six to eight inches deep, then place potatoes 12 inches apart, eyes facing up. Cover with four inches of soil. As the plant grows, "hill" the soil by adding more on top: Hilling ensures that the tubers stay underground and don't turn green. (Green potatoes are toxic.) Continue adding soil when your potatoes grow four to six inches until they flower, leaving the top few inches of leaves exposed.
- Individual hole or "scatter" methods: Dig individual holes six to eight inches deep and wide, place a potato in each hole, then cover it with four inches of soil or mulch. You can also place your potatoes directly on top of the soil before covering (scatter method). Like the trench-and-hill method, continue adding soil or mulch as the plants grow until they flower. Scattering can make your potatoes more susceptible to rodents, so choose whether to dig holes depending on common pests in your area.
- In containers, such as barrels, trash cans, or wire enclosures: Place six inches of soil in the bottom, place potatoes on top of the soil, then cover with an additional four inches of soil. Cover any exposed tubers with soil as your potatoes grow until they flower.
Potato Plant Care
Grow your potatoes in full sun, ensuring that they receive at least six hours of direct sunlight per day. Always ensure that the tubers themselves are covered with soil or mulch to avoid turning green. Allow the plant's foliage to soak up plenty of sunlight to feed the potatoes growing underground.
Plant potatoes in neutral to acidic soil with organic matter to offer plenty of nutrients. Ensure the soil is well-draining (use a pot with drainage holes if planting in a container). The pH should be between 5.0 and 6.0 for best results—less acidity in the soil can cause rough spots called "scab." Regions with clay soil can still create bountiful harvests, but it's important to prepare it by spreading two to four inches of organic matter in your garden, trench, or planting holes first to increase drainage and aeration.
Potatoes only require one inch of water per week, but they can be affected by drought if not watered consistently. You can mulch the area to retain more water or utilize an automatic irrigation system when growing larger amounts of potatoes. Be sure that the plants receive plenty of water when flowering to encourage the healthy growth of tubers.
Temperature and Humidity
In cold climates, wait until the soil temperature has reached 40 to 50 degrees Fahrenheit before planting. Since your potatoes will stop growing once the soil reaches 80 degrees or higher, warm-climate potatoes are best planted in the late summer or late winter. In the southernmost parts of the U.S., it's best to grow your potatoes during the winter (or add a thick layer of mulch above them to cool the soil up to 10 degrees).
If you've amended your soil with compost, your potatoes won't require fertilizer. If you haven't been using compost or other organic matter, you can mix a balanced organic fertilizer, diluted liquid fertilizer, or other natural options like fish emulsion into the soil (following the label instructions).
Potato plants are self-fertilizing, meaning that you won't need to take any extra pollination steps to ensure yours grow to maturity. Tubers grow underground while both male and female flowers form on the foliage of the plant, which may receive additional pollination by the natural environment (but isn't necessary for its growth).
Types of Potatoes
While more than 4,000 types of potatoes exist around the world, there are a few common varieties that you're more likely to encounter as a gardener. Here are some popular variants to grow:
- Russet potatoes are the type that most gardeners in the U.S. are familiar with, featuring a rounded shape and thick, dense feeling to the touch until cooked. 'Norkotah' and 'Burbank' are popular varieties.
- Red potatoes grow smaller than russet potatoes and feature a reddish tint to their thin skin. 'Red Pontiac' and 'Viking' are varieties known for their easy growing habits, while 'Chieftan' and 'Norland' varieties are more resistant to potato scab.
- Yellow potatoes are versatile for cooking in a wide range of recipes, and their flavor has hints of sweet butter. 'Yukon Gold' is a popular variety in the U.S. that grows with thin skin and no eyes,
- Sweet potatoes have a naturally sweet flavor that makes them a common pick for dessert recipes and spiced seasonings. 'Beauregard' and 'Jewel' are popular varieties for gardeners to grow.
- Fingerling potatoes are easily identifiable by their long, thin shape that is thought to resemble fingers. 'French Fingerling' is a red variety that is often cooked without peeling, while 'Ozette' features a golden color with a nutty taste.
Potatoes vs. Yams
While potatoes and yams have many similar characteristics, yams are actually members of the Dioscorea family rather than the nightshade. They're often confused with sweet potatoes, which feature a red tint to their skin with sweet-tasting flesh that grows in a variety of colors. The easiest way to differentiate between the two is their skin: Yams have rough, brown skin that feels like bark, and they feature white flesh similar to russet potatoes.
One plant will typically yield between two and 10 pounds of potatoes. Once your plant has reached about one foot in height or 50 days since planting, it's safe to harvest a few small potatoes. New potatoes are small, and they can be harvested in larger numbers at any time during the season once you see blooms on the plant. After the foliage above ground dies, it's safe to harvest the entirety of your potatoes.
If you are growing potatoes to store, let the foliage turn brown. Cut it back, then leave the potatoes in the ground for a few more weeks (being sure to harvest before your region gets a hard frost).
The best way to harvest potatoes is to use a digging fork and start at the outer edge of the hill or trench. Try to get the fork as deep into the soil as possible, then lift up to harvest your potatoes. Separate any potatoes that have been penetrated with the fork: Once the skin is broken, they won't stay fresh long, so it's best to eat these first.
You can save seed potatoes from your garden from year to year. Simply store healthy tubers in a cool, dry spot. Do not wash before storing. Let the potatoes sit out for a few days after harvesting so that any soil clinging to the tubers dries thoroughly. The benefit of storing seed potatoes is that over time, you'll end up with a strain of potatoes that is particularly suited to conditions in your garden.
How to Grow Potatoes in Pots
If you don't have the space in your garden, you can easily grow potatoes in containers. Choose a tall option—clean garbage can, barrel, five-gallon bucket, or planting bag specified for potatoes—and start with six inches of soil. Like growing potatoes in the ground, it's important to ensure the tubers don't reach sunlight. Spread seed potatoes across the first layer of soil before covering them up with additional layers of soil, peat moss, or a combination of both (thanks to its acidic nature, peat moss helps prevent potato scab). Every time the foliage grows between four and six inches, add another layer. Harvest the potatoes once the plants flower.
Pruning is not necessary for potato plants, but some gardeners use various methods of pruning to change the outcome of each potato. To grow your potatoes larger, allow the stalks to grow fully and flower, as the foliage above ground feeds the potato below by soaking in sunlight and nutrients. For smaller potatoes, trim the stem just below the flowers. Do a size test by harvesting one potato. Once they've reached your desired size, cut the remaining length of the stalk to keep them from growing further.
Since the seed potatoes themselves are planted, you'll have to propagate potatoes from an existing plant or buy seed potatoes intended for gardening to begin. Once you've harvested the first round of new potatoes from your plant, you can plant them whole or cut them into smaller pieces to grow new plants.
Ensure that each piece retains at least a few eyes (up to three). It's helpful to leave cut pieces out for a few days to allow the sides to callus over—this prevents rotting if the soil is cold or retains too much moisture.
Potting and Repotting Potatoes
Many gardeners transplant their potatoes into new containers when the plants are becoming too crowded. To repot your potatoes, it's important to first determine the timing: Avoid repotting potato plants during the winter, and wait until a week or two before the last frost to ensure optimal temperatures.
Repotting is best done before the roots have matured in the soil, so plan to move these plants while the foliage is young. If you need to repot an established potato plant, it's helpful to trim back some of the leaves (carefully ensuring to leave any budding flowers intact) to lessen the weight on the stalk.
Because potatoes can be harvested at any time during the growing season, you can cut their stalks down to the soil level to keep them as long as needed until winter. Once colder temperatures hit your region, it's important to harvest your potatoes before the ground freezes. To keep excess potatoes fresh and safe to eat over the winter, allow the plant to completely mature through its growth cycle (letting the foliage die at the end of the season) before harvesting. Store the potatoes in a place with high humidity for one to two weeks before moving them to a cold, dry space with just above freezing temperatures where they can be kept throughout winter. Use brown paper bags as a container in winter, and ensure your potatoes are kept away from stored fruits.
Common Pests and Plant Diseases
Several pests are known to infest potato plants, and many can be prevented by covering your potato patch with a floating row cover to help protect them. Common pests and diseases for potatoes include:
- Colorado potato beetle: Handpick beetles, larvae, and eggs from plants.
- Flea beetles: Keep the area weed-free so you don't provide cover for flea beetles. Spray infested plants with insecticidal soap.
- Redworms: Since redworms infest potatoes underground, change the planting location from season to season to prevent returning pests.
- Leafhoppers: Spray with water from the hose.
- Aphids: Monitor the underside of the plant's foliage for eggs. These can be removed by hand or sprayed from the plants with a hose.
- Scab: Practice crop rotation to avoid transmission, or plant resistant varieties (e.g., 'Norland', 'Chieftain', and 'Russet Burbank').
- Late blight: Late blight was the cause of the Irish potato famine. This disease covers the plants' foliage in a dark black, moldy substance. Practice crop rotation and clean up the previous season's foliage and tubers. Also, plant resistant varieties (e.g., 'Sebago', 'Elba', and 'Allegheny'). If your plants experience late blight, burn the foliage rather than composting to prevent any spread.
Are potatoes easy to grow?
Potatoes are known for their easy growth habits. They can be grown in many regions of the world, and with plenty of direct sunlight, the plants typically produce between two and 10 pounds of potatoes.
How long does it take to grow potatoes?
Some early-season varieties of potatoes can be harvested in about two months, while late-season varieties can take between three and four months to mature.
Can you grow potatoes indoors?
Potatoes can easily be grown in containers indoors as long as they receive proper sunlight. Choose a sunny, south-facing window to grow your plants, or opt for a grow light in darker rooms to produce a full harvest.
The Problem With Potatoes. Harvard School of Public Health.
Pei, Diana M. Are Sprouted Potatoes Safe to Eat? Poison Control.
Potato Facts and Figures. International Potato Center (CIP).