-
-
Potatoes are one of the most widely used vegetables in the United States. However, the vegetable can be susceptible to a number of diseases and viruses. Knowing the proper method of how to grow potatoes is essential if you want to have a healthy and bountiful crop.
-
Growing Potatoes Tips
- Potatoes come in a variety of colors, including red, yellow and blue.
- Different varieties are good for different uses.
- Planting certified seed potatoes will help minimize problems with disease.
- Potatoes should not be grown in the same spot two years in a row.
- Careful harvesting is necessary to avoid post-harvest diseases.
-
Introduction
- The potato seems as American as apple pie and the bald eagle, but in reality it is grown around the world. While most people love to eat them, the potato has been used for other things such as powering clocks and embarrassing vice presidents.About.com: Potato Clock - Make a Potato Battery to Power an LED Clock Capital Century: 1992: Gaffe with an 'e' at the End No matter what you want to use them for, nothing is more satisfying than using the potatoes you grew yourself.
Types of Potatoes
- With over 500 varieties of potato on the market, you may find it difficult to choose just one. Usually, you should choose a variety of potato that is well-suited for what you plan on using it for. Here are a few of the more common ones you will find on the market.
Early Season
- Frontier Russet: Early to medium-early season russet potato with white flesh and shallow eyes.
- Resistant to verticillium wilt, fusarium dry rot and common scab but susceptible to early blight.NC University: Vegetable Cultivar Descriptions for North America: Potato The Potato Association of America: Frontier Russet
- Excellent for french fries at harvest and good for baking.Canada Food Inspection Agency: Frontier Russet
- Norgold Russet: Early season russet potato.
- Norland, Red Norland and Dark Red Norland: Early season red skinned potato with white flesh and shallow eyes.
- Red Norland and Dark Red Norland are clones or mutations of Norland.University of Nebraska–Lincoln: Norland: Characteristics
- Highly resistant to scab; resistant to leafroll and potato viruses A and Y.Cornell University: 'Dark Red Norland' Potatoes
- Excellent for boiling and frying; good for baking.The Potato Association of America: Norland
- Russet Norkotah: Early season russet potato.
- Tuber physiological disorders are very rare even in dry conditions.Oregon State University: Grow your Own Potatoes
- Highly resistant to common scab but very susceptible to verticillium wilt and blights.NC University: Vegetable Cultivar Descriptions for North America: Potato University of Nebraska–Lincoln: Russet Norkotah: Characteristics
- Superior: Early to midseason potato with white, white flesh and shallow eyes.
- Excellent for long storage.Cornell University: 'Superior' Potatoes
- Excellent for chipping; okay for baking, boiling and frying.Canada Food Inspection Agency: Superior
- Resistant to net necrosis and common scab; moderately resistant to internal heat necrosis; but susceptible to blackleg, fusarium, leafroll virus, verticillium wilt and some viruses.The Potato Association of America: Superior
Midseason
- Goldrush: Midseason russet potato with shallow eyes.
- Very resistant to drought, common scab, black spot bruising, verticillium wilt and hollow heart but susceptible to most common potato viruses and other potato diseases.Cornell University: 'Gold Rush' Potatoes The Potato Association of America: Goldrush
- Excellent for baking and boiling.Canada Food Inspection Agency: Goldrush
- Kennebec: Mid to late season potato with white skin and flesh and shallow eyes.
- Red Pontiac: Midseason red potato with deep eyes.
- Yukon Gold: Mid to late season potato with yellow skin and flesh and medium-deep eyes.
- Yukon Gold has become very popular recently.University of Nebraska–Lincoln: Yukon Gold: Characteristics
- Good for boiling, baking and french frying but not chipping.Canada Food Inspection Agency: Yukon Gold
- Resistant to mild mosaic and moderately resistant to the leafroll virus.The Potato Association of America: Yukon Gold
Late Season
- All Blue: Late season potato with blue to purple skin and flesh with medium to shallow eyes.
- Butte: Late season russet potato with white flesh shallow eyes.
- Katahdin: Late season potato with white skin and flesh and shallow eyes.
- Russet Burbank: Late season russet potato with medium-deep eyes.
- The most popular cultivar grown in the United States.University of Nebraska–Lincoln: Russet Burbank: Characteristics
- Excellent for baking and processing; stores well.The Potato Association of America: Russet Burbank
- Resistant to black leg and moderately resistant to common scab and fusarium dry rot.Canada Food Inspection Agency: Russet Burbank
Potato Variety Lists
- For more information about additional varieties of potatoes, check out one of the following lists:
- NC State University: Vegetable Cultivar Descriptions for North America: Potato
- Oregon State University: Variety Selection
- Cornell University: Vegetable Varieties for Gardeners: Potatoes
- Washington State University: Potato Varieties: A Comprehensive List
- Washington State University: Specialty Potatoes
- Potato Goodness.com: Potato Varieties Grown in the U.S.
Soil Requirements
- Potatoes need a well-draining fertile soil to thrive and should not be grown in the same location each year. Wait at least three years before planting potatoes in a spot where they have previously been grown.Penn State College of Agricultural Sciences: Growing Potatoes
- Potatoes do best with a pH level of 5.0 to 6.0.DIY Network: Selecting and Growing Potatoes
- Do not plant potatoes in areas with dry sands, shales or heavy clay loam soil.Penn State College of Agricultural Sciences: Growing Potatoes
- Soil should be fertilized with a 05-10-10 fertilizer.DIY Network: Selecting and Growing Potatoes
- Do not over fertilize, which can encourage potato scab.DIY Network: Selecting and Growing Potatoes
Cutting and Handling Seed Potatoes
- Potatoes are not true seeds, but are planted from stem tissue known as "tuber." You can purchase seed potatoes from your local garden center or through a mail order company.Penn State College of Agricultural Sciences: Growing Potatoes Most seed potatoes will need to be cut and dried before planting.
- Use certified seed potatoes. Certified seed is grown under strict guidelines and thoroughly inspected by state authorities.Penn State College of Agricultural Sciences: Growing Potatoes
- Do not use homegrown potatoes because they are likely heavily infested with viruses that will ruin your crop.Oregon State University: Grow your Own Potatoes
- Supermarket potatoes cannot be used because they are usually treated with chemicals that permanently inhibit sprouting or may harbor diseases, even organically grown varieties.Oregon State University: Grow your Own Potatoes DIY Network: Selecting and Growing Potatoes
- Certified seed is not guaranteed to be disease free, but rather will have a less percentage of disease.UC IPM Onlne: Seed Certification and Seed Tuber Handling
- Bacterial ring rot, blackleg, common scab, late blight, potato viruses, powdery scab, Rhizoctonia, root knot nematodes, silver scurf and wilt diseases can all be carried through infected seed tubers.UC IPM Onlne: Seed Certification and Seed Tuber Handling
- Try to purchase your seed potatoes two to three weeks before you anticipate planting them so you can "sprout" them.Penn State College of Agricultural Sciences: Growing Potatoes
- Place the potatoes one layer deep in a warm (70°F) area with direct sunlight.Penn State College of Agricultural Sciences: Growing Potatoes
- Turn the potatoes to "green" the skin's surface and allow 1/4 to 1/2 inch long sprouts to form.Penn State College of Agricultural Sciences: Growing Potatoes
- This should cause your plants to emerge one to two weeks earlier.Penn State College of Agricultural Sciences: Growing Potatoes
- Seed potatoes come in a variety of sizes. B-sized tubers weigh only an ounce or two and do not require cutting.DIY Network: Selecting and Growing Potatoes
- Larger seed potatoes should be cut into smaller pieces.
- Your ideal seed piece should block shaped, weigh between 1 to 2 ounces (about the size of a golf ball or ice cube) and have at least two "eyes" or buds on it.Oregon State University: Grow your Own Potatoes
- Make the first cut lengthwise in order to divide the cluster of buds at the end of the potato.Penn State College of Agricultural Sciences: Growing Potatoes
- Cut the potato as little as possible.Oregon State University: Grow your Own Potatoes
- Smaller-sized pieces can result in weaker plants and make them more vulnerable to late frost injuries.Penn State College of Agricultural Sciences: Growing Potatoes
- Each pound of seed potatoes should contain about eight to ten seed pieces.Penn State College of Agricultural Sciences: Growing Potatoes
- Store the cut pieces for one to seven days before planting to allow the surface to dry and form a callus, which will decrease the chance of rot.UC Davis: Potato, white
- Pieces should be stored at room temperature (60 to 70°F) in an area with high humidity and good ventilation.Penn State College of Agricultural Sciences: Growing Potatoes
- A closed (but not sealed) cardboard box with ventilation holes is an ideal location to store cut pieces.Oregon State University: Grow your Own Potatoes Pieces can be piled about 6 inches deep.
- Do not store pieces in an airtight container.Oregon State University: Grow your Own Potatoes
How to Plant
- Once the seed potatoes have been properly prepared, you are ready to plant your potatoes.
When to Plant
- Potatoes can be planted any time from from March until mid-June.Oregon State University: Grow your Own Potatoes
- The morning soil temperature should be at least 48 to 50 degrees F at a depth of 4 inches before planting.Penn State College of Agricultural Sciences: Growing Potatoes
- Planting too early can cause seed pieces to rot.University of Illinois Extension: Watch Your Garden Grow: Potato
Spacing
- Rows should be spaced 2 to 4 feet apart.
- Seeds should be spaced between 6 to 15 inches apart.
- Seed spacing depends on the variety of potato, depth of soil, soil fertility and moisture levels of the soil during the season.Penn State College of Agricultural Sciences: Growing Potatoes
- Allow more space between your seeds if you want larger potatoes; less space for smaller potatoes.Oregon State University: Grow your Own Potatoes
Planting Tips
- Till the soil about 6 to 8 inches deep before planting. Do not over till, which can cause the soil to seal over and lead to seed piece suffocation and death.Oregon State University: Grow your Own Potatoes
- Potatoes should be planted in furrows at a depth of about 2 to 4 inches.
- Plant the cut side down with the eyes pointing up.DIY Network: Selecting and Growing Potatoes
- Rows should be slightly mounded to allow water to drain from the seed pieces and reduce decay.Oregon State University: Grow your Own Potatoes Penn State College of Agricultural Sciences: Growing Potatoes
- If a late, severe frost is expected, protect young plants with a temporary covering of straw or newspaper.Penn State College of Agricultural Sciences: Growing Potatoes
Straw Potatoes
- A special method of growing potatoes that does not require cultivation or hilling is called "straw potatoes." This involves placing the seeds and rows the same way as listed below, but instead of burying the seeds they are covered with 4 to 6 inches of straw, cornstalks or other mulch type material.Penn State College of Agricultural Sciences: Growing Potatoes This method is often used by gardeners who are growing potatoes for competition because the tubers are better shaped.University of Illinois Extension: Watch Your Garden Grow: Potato
Potato Plant Care
- The two most important areas of potato plant care are cultivation and watering. Cultivation allows you to eliminate weeds, loosen the soil and hill the plants.
Cultivation, Hilling and Weed Control
- Cultivation will help break up the soil around your plants. This will get rid of weeds, help aerate the soil and allow you to ridge the row.University of Illinois Extension: Watch Your Garden Grow: Potato This process is known as "hilling" or "dirting." Hilling is done to cover areas of the stem so potatoes can develop.Penn State College of Agricultural Sciences: Growing Potatoes It will also reduce the number of "sunburned" or green tubers.University of Illinois Extension: Watch Your Garden Grow: Potato
- Hilling should begin when plants are about 6 to 8 inches high.Penn State College of Agricultural Sciences: Growing Potatoes
- Mound the soil around the base of the plant to form a ridge.
- You can either leave a few of the upper leaves exposed or bury the entire plant under the soil.DIY Network: Selecting and Growing Potatoes
- You will probably need to hill two to three times during the season to ensure that new tubers do not push out of the soil.DIY Network: Selecting and Growing Potatoes
- By the time the plants are 15 to 18 inches tall, the ridge should be between 4 to 8 inches high and 10 to 12 inches across.Penn State College of Agricultural Sciences: Growing Potatoes Oregon State University: Grow your Own Potatoes
- Cultivation should be at depths of less than 2 inches.Penn State College of Agricultural Sciences: Growing Potatoes
- Be careful when hoeing around potato plants as they can be easily damaged.University of Illinois Extension: Watch Your Garden Grow: Potato Cut tubers are more likely to develop disease and viruses.
- Stop cultivation and hilling after the plants have bloomed to avoid damaging the roots.Oregon State University: Grow your Own Potatoes
- Avoid using herbicides to control weeds. No herbicide can be used safely around all types of vegetables and are difficult to apply at proper rates in small areas.Penn State College of Agricultural Sciences: Growing Potatoes
- Mulching is an effective measure for weed control around potato plants and will help conserve soil moisture while helping to maintain a uniform soil temperature.Penn State College of Agricultural Sciences: Growing Potatoes
Watering
- Proper moisture is essential to potato growth. The exact amount of water that potatoes need depends on soil type, temperature, wind and other factors.Penn State College of Agricultural Sciences: Growing Potatoes However, on average they will need between 1.5 to 2 inches of water per week until just before harvesting.Oregon State University: Grow your Own Potatoes
- Do not water before plants emerge unless necessary. Wet soils can lead to seed decay.
- Potatoes should be watered by mid-day so that the leaves dry before nightfall and avoid encouraging fungal and bacterial diseases.Oregon State University: Grow your Own Potatoes
- During dry weather, watering is essential when the vines are 6 to 8 inches tall and about two weeks before harvesting.Penn State College of Agricultural Sciences: Growing Potatoes
- Regular watering will reduce knobbiness, second growths, cracking and hollow cavities in tubers.Penn State College of Agricultural Sciences: Growing Potatoes
- Because roots do not penetrate more than 18 inches into the soil, you can generally will only need to water once a week.Oregon State University: Grow your Own Potatoes Sandy soils may need watering more often.
- Avoid frequent, light waterings that wet the surface but leave the roots dry.Oregon State University: Grow your Own Potatoes
Dealing with Disease
- Disease control has more to do with planting correctly and controlling insects since seed tubers and pests carry many of the diseases listed below.Oregon State University: Grow your Own Potatoes Potato disease can be broken down into three major categories: foliage diseases, tuber and stem disease and viruses. Only the more common diseases will be discussed here; however, links to information on less common varieties can be found under Other Diseases. Information on diseases that affect potatoes during storage is found under Harvesting and Storage.
Foliage Diseases
- Foliage diseases generally affect the leaves of the potato plant, but may affect the tubers as well.
- Early Blight
- Early blight is caused by the fungus Alternaria solani. It very common and found in most areas.Vegetable MD Online: Potato Early Blight (Alternaria solani Sorauer)
- Symptoms appear on older foliage first. Leaves develop circular to angular dark brown lesions about 1/5 inch in diameter.UC IPM Onlne: Early Blight Rings often form in the lesions to produce a pattern similar to a bulls-eye.
- Fungicide programs used to control late blight are usually effective against early blight.Michigan State University: Early Blight
- Late maturing cultivars are typically more resistant to early blight. Some highly susceptible cultivars include Red Norland, Norchip and Superior.Michigan State University: Early Blight
- Late Blight
- Late blight caused the Irish potato famine in the mid-nineteenth century and an epidemic in the 1840s in the United States.Vegetable MD Online: Late Blight of Potatoes and Tomatoes
- First appears as small pale to dark green water-soaked lesions that are irregular in shape and surrounded by yellowish tissue.UC IPM Online: Late Blight
- Late blight lesions are more watery and spread down the petiole and the stem than early blight lesions.Michigan State University: Foliar Diseases/Conditions of Potato
- Development of late blight is favored by high moisture or humidity above 90 percent with moderate temperatures (50 to 80°F for periods of at least 8 to 10 hours).Vegetable MD Online: Potato Late Blight (Phytophthora infestans)
- New strains introduced from Mexico in the 1990s have increased the severity of late blight on tomatoes and potatoes in the United States and Canada.Vegetable MD Online: Late Blight of Potatoes and Tomatoes
- Control of late blight is usually done with fungicides.Vegetable MD Online: Late Blight Concerns for Potatoes in 2003
- You can find research publications, extension publications and recent publications from Michigan State University on potato diseases on its website. Michigan State University: Research Publications Michigan State University: Extension Publications Michigan State University: Recent Publications
- Verticillium Wilt
- First signs are usually when the lower leaves on the vine turn yellow and wither.UC IPM Online: Verticillium Wilt It can also cause chlorosis and discoloration of the vascular ring in both the stem and the tuber.Michigan State University: Foliar Diseases/Conditions of Potato
- Most potato varieties are not resistant to this disease, especially Kennebec.North Dakota State University: Management Of Potato Diseases in the Home Garden
- Verticillium can be controlled using clean seed, seed treatments and crop rotation.Michigan State University: Foliar Diseases/Conditions of Potato
Tuber and Stem Diseases
- Tuber and stem diseases can be more difficult to detect because their signs are not as noticeable. Often you won't be aware that there is a problem until after harvesting the potatoes. However, since many of these diseases can occur year after year, it is important to know what their signs and symptoms are in order to prevent it from occurring again.
- Bacterial Soft Rot and Blackleg
- Both caused by varieties of the bacterium Erwinia carotovora.
- Blackleg usually affects young plants that are planted in cool, wet soil.UC IPM Online: Bacterial Soft Rot and Blackleg
- Soft rot occurs when bacteria enters the tuber through a wound or other point of entry.Michigan State University: Tuber and Stem Diseases/Conditions of Potato
- Controlling these diseases is done primarily by planting certified seed, controlling moisture, crop rotation and proper planting.Penn State College of Agricultural Sciences: Growing Potatoes North Dakota State University: Management Of Potato Diseases in the Home Garden
- Black Dot
- Black dot is caused by the fungus Colletotrichum coccodes' and is both tuberborne and soilborne.Vegetable MD Online: Black Dot Disease of Potatoes
- First appears as a yellowing and wilting of plants in the middle to late season.UC IPM Online: Black Dot
- Seed-piece fungicides are not effective in controlling black dot.Vegetable MD Online: Black Dot Disease of Potatoes
- Black dot can also affect tomatoes, eggplants and peppers.
- Black Scurf and Rhizoctonia Canker
- Both diseases are caused by the soil fungus Rhizoctonia solani.
- Most noticeable signs are wilting plants or hard black crusty spots resembling dirt on the tubers that can't be washed off, called "scurf."North Dakota State University: [Management Of Potato Diseases in the Home Garden] Vegetable MD Online: Rhizoctonia Disease of Potato
- Control can be achieved through seed treatments, crop rotations, using clean seed and soil fumigation.Michigan State University: Rhizoctonia Stem Canker and Black Scurf of Potato
- Common Scab
- Common scab is caused by Streptomyces scabies, which is present in almost all soils.Vegetable MD Online: Potato Scab
- Symptoms of common scab vary in extent and appearance but include some type of leisions.UC IPM Online: Common Scab
- The disease is worse in alkaline soils and during droughts.Penn State College of Agricultural Sciences: Growing Potatoes
- Resistant potato varieties include Russet Norkotah or Goldrush; Moderately resistant varieties include Norland or Superior.North Dakota State University: [Management Of Potato Diseases in the Home Garden]
Viruses
- Viruses can infect potatoes and cause numerous problems such as leaf or tuber malformations, growth problems and reduce yield.Vegetable MD Online: Virus Problems of Potatoes You can greatly reduce the chances of viruses by planting only certified seed and controlling insects.Penn State College of Agricultural Sciences: Growing Potatoes The most common virus that affect potatoes include:
Dealing with Pests
- Although there are several different types of pests that can attack potatoes, only one or two insecticides are necessary to control almost all of them.Oregon State University: Grow your Own Potatoes Often you can control them with insecticidal soap.UC Davis: Potato, white Mesh row covers are another method of controlling insects, but are expensive and inconvenient to use. If you do use insecticides, spray them early or late in the day when bees are less active since most insecticides are toxic to honeybees.Oregon State University: Grow your Own Potatoes
Other Diseases
- Potatoes can be susceptible to a few other disease not listed above, although they are less common. These diseases include:
Aphids
- Aphids are small soft-bodied insects that suck the sap out of plant leaves and stems. They come in various colors but are usually green, pink or gray and may or may not have wings.
- Aphids often carry viral diseases.
- Green peach aphids and potato aphids are the two most common varieties found on potatoes.UC IPM Online: Aphids
- Aphids cluster on the undersides of leaves and shoot tips.Oregon State University: Grow your Own Potatoes
- Vines of infested plants often become covered with a thick, sticky honey dew that is excreted by aphids.Oregon State University: Grow your Own Potatoes
Colorado Potato Beetles
Flea Beetles
- Flea beetles are very small (1/16 inch) black beetles that can leave holes or white streaks on leaves in the late spring.University of Illinois Extension: Watch Your Garden Grow: Potato
- They will also attack cabbages, eggplants, radishes, spinach, sweet corn and turnips.
- Severe cases can kill off leave and decrease your yield.University of Illinois Extension: Watch Your Garden Grow: Potato
- Good sanitation around your garden will help control flea beetles.Penn State College of Agricultural Sciences: Growing Potatoes
- Special controls for flea beetles is rarely necessary since damage is not usually noticed until after harvest.UC IPM Online: Flea Beetles
Leafhoppers
- Leafhoppers (also known as beet leafhoppers) are green, wedge-shaped insects about 1/10 to 3/8 inch long.
- Symptoms of infestation include curled or crinkled foliage and "hopper burn," which turns the edge of the leaves brown.University of Illinois Extension: Watch Your Garden Grow: Potato Older leaves will be affected first.Penn State College of Agricultural Sciences: Growing Potatoes
- They also attack beans, carrots, cucumbers and muskmelons.
- Leafhoppers spread the curly top virus.UC IPM Online: Beet Leafhopper
- Insecticides used to control aphids and flea beetles will also control leafhoppers.UC IPM Online: Beet Leafhopper
Wireworms
- Wireworms are thin brown hard-bodied worms that can grow up to 1-1/2 inches long.
- The larvae bore deep funnel-shaped holes into the potato.
- More common in gardens that were used as a waste area or pasture areas full of grass, clover or weedy alfalfa.Penn State College of Agricultural Sciences: Growing Potatoes UC IPM Online: Wireworms
- Granular insecticides can be used to control wireworms, but you may need to rotate crops or move the whole garden to get rid of them.Oregon State University: Grow your Own Potatoes
- You can detect wireworms by baiting: place carrots or untreated corn about 4 to 6 inches into the soil when the soil temperature is 50°F.UC IPM Online: Wireworms
Harvesting and Storage
- You will know that your potatoes are ready to harvest when the leaves yellow and the foliage starts to die back. This will occur about 70 to 100 days after planting, depending on the variety.DIY Network: Selecting and Growing Potatoes
- In order to reduce peeling, bruising and rot during storage, do not dig up the potatoes until two weeks after the vines have naturally died down.Ohio State University: Growing Potatoes in the Home Garden Do not water during this time.DIY Network: Selecting and Growing Potatoes
- If the skin is thin and rubs off easily, the potatoes are not ready to harvest.DIY Network: Selecting and Growing Potatoes
- Use a shovel or spading fork to dig out the potatoes, which are growing about 4 to 6 inches below the soil's surface.University of Illinois Extension: Watch Your Garden Grow: Potato Be careful not to bruise or cut into the potatoes.
- If harvesting when temperatures are above 80°F, place potatoes into a dark area immediately to prevent them from turning green or rotting.Ohio State University: Growing Potatoes in the Home Garden
- If you want to store potatoes for longer than six weeks, you need to cure the potatoes.
- Curing is done by placing the potatoes in a dark place with a temperature between 60 to 65°F and a humidity level above 85 percent for 10 to 14 days.Ohio State University: Growing Potatoes in the Home Garden
- After potatoes are cured, toss out any potatoes that are soft and shriveld.DIY Network: Selecting and Growing Potatoes Then, store them in a cool (40 to 45°F) dark place with high humidity.Ohio State University: Growing Potatoes in the Home Garden
Other Pests
- Some of the other pests that can be found on potatoes, although less often, include:
Post Harvest Diseases
- Potatoes are susceptible to a number of post harvest diseases that are usually caused by fungii.University of California: Potato Storage Diseases
- Some of the most common post harvest diseases include:
Conclusion
- Now that you have your homegrown potatoes, it is time to decide how you want to eat them. Your choices are numerous: potato salad, french fries, mashed potatoes, au gratin potatoes, scalloped potatoes, twice baked potatoes, baked potatoes and potato chips. Of course, if you're not sure how to make one of those items, check out some of Mahalo's How To pages like How to Make Potato Salad, How to Make Potato Chips, How to Bake a Potato, How to Make Mashed Potatoes and How to Microwave a Potato.
Featured Pages
