10-10-10 fertilizer for potatoes

What Does a Potato Plant Look Like?

The Potato Plant

Potatoes are a cool-season root crop that can be grown in all USDA Zones. Members of the nightshade family, they may grow several feet above ground. However, it is the swollen portions of the roots that become the edible tubers people eat. Potatoes come in a number of colors and in different shapes – there are more than 4,000 known potato varieties.

Growing Potatoes

Potatoes are one of the easier vegetable crops to grow. They require:

  • Very fertile soil, rich in potassium and nitrogen.
  • Excellent drainage to prevent fungal disease.
  • Regular water while growing.
  • Hilling – adding soil to partially bury the vine as it grows.
  • Curing in a warm, dark area for a week or two prior to storage.

Above Ground

If you’ve ever seen a tomato plant, you may have noticed that it looks a lot like a potato. These “cousins” share several characteristics. The leaves are shaped like tear drops and have lightly serrated edges. Leaves are light to dark green and heavily crinkled. Many feel fuzzy to the touch. Leaves occur alternately on the stem.

Below Ground

The stem of the potato is usually white to ivory-colored. Although a few roots grow along its length, most are clustered at the bottom of the plant. Potato tubers develop all along the buried stem. This characteristic is why potatoes are hilled by placing additional soil on the growing tops. The plant will develop more tubers along the buried stem.

Colors and Shapes

The potato vine is usually light to dark green, but some varieties may have pink or purple tinges, especially in the new shoots. The tubers themselves may be tan, red, purple, blue, yellow or gold on the outside. White flesh is common no matter what the outside color, but some varieties are red, yellow, blue or purple inside. Shapes range from round or oval to elongated oblong.

Flowers

Potato flowers are often striking. The petals may be individual or connected, and many have points or ruffled edges. Colors range from white through blue, purple and pink. Whatever the base color, the flower may be streaked or tinged with pink or white. The flowers may produce tiny green seed balls that resemble clusters of cherry tomatoes.

New! Click or tap to view the new Growing Potatoes guide

By: Joseph Masabni

Irish potatoes are one of America’s most popular vegetables—the average American eats about 125 pounds of potatoes and potato products each year.

The edible part of the plant is an underground stem called a tuber (not a root). Irish potatoes contain 2 percent protein and 18 percent starch. They are an inexpensive source of carbohydrates and, when prepared properly, provide good amounts of vitamins and minerals.

Irish potatoes are a cool-season crop; they grow best in early spring and late fall when the days are warm and the nights are cool. However, the tops of the plant cannot withstand frost.

Varieties

The most common types of Irish potatoes are red or white. Most red varieties store longer than do white varieties; on the other hand, most white varieties have better cooking qualities than red varieties.

Many gardeners plant some of each in the spring. The whites are used first and the reds stored for later use. Several varieties grow well in Texas:

  • Red flesh: Dark Red Norland, Norland, Red LaSoda, and Viking
  • White flesh: Atlantic, Gemchip, Kennebec, and Superior
  • Yellow flesh: Yukon Gold
  • Russet: Century Russet, Norgold M, and Russet Norkatah

Site selection

For best production, potatoes need full sun. They do best in a loose, welldrained, slightly acid soil. Poorly drained soils often cause poor stands and low yields. Heavy soils can cause the tubers to be small and rough.

Soil preparation

Before spading, remove the rocks, trash, and large sticks from the soil. Spade he soil 8 to 12 inches deep turning the earth over to cover all plant material.

Work the soil into beds 10 to 12 inches high and 36 inches apart (Fig. 1). Bedding is vital for drainage.

Figure 1. Before planting potatoes, work the soil into beds 10 to 12 inches high and 36 inches apart.

Because potatoes need adequate fertilizer early in the season, apply most of the fertilizer just before planting. Use 2 to 3 pounds of complete fertilizer such as 10- 20-10 for each 30 feet of row in bands 2 inches to each side and 1 inch below the seed piece. Do not allow the fertilizer to touch the seed piece.

Figure 2. Flatten the beds at 6 to 8 inches high and 10 to 12 inches wide.

To apply the fertilizer, flatten the beds at 6 to 8 inches high and 10 to 12 inches wide (Fig. 2). Using the corner of a hoe or stick, open a trench about 4 inches deep on each side of the bed. Apply half of the fertilizer—about 2 cups for each 30 feet of row—in each trench.

The seed pieces will be planted in the row between the two bands of fertilizer (Fig. 3).

Figure 3. Plant the seed pieces in a row between two bands of fertilizer.

Seed preparation

Unlike most other vegetables, Irish potatoes are not grown from seed. Instead, pieces from the potato itself start new plants. Buy good seed potatoes that are free of disease and chemicals. Do not buy potatoes from a grocery store for planting.

The seed potato contains buds or “eyes” that sprout and grow into plants. The seed piece provides food for the plant until it develops a root system. If the seed is too small, it will produce a weak plant. One pound of seed potatoes will make 9 to 10 seed pieces.

For a spring crop, cut large seed potatoes into pieces weighing about 1½ to 2 ounces, about the size of a medium hen egg. Each seed piece must have at least one good eye (Fig. 4).

Cut the seeds 5 or 6 days before planting. Hold the cut seed in a well-ventilated spot so it can heal over to prevent rotting when planted in cold, wet or very hot weather. Plants killed by a late spring frost will not come back if the seed piece is rotten.

Figure 4. Cut large seed potatoes into pieces, each having at least one good eye.

For fall-grown potatoes, plant small, uncut potatoes because they are more resistant to rotting in hot weather than cut potatoes. Select mature potatoes about 1½ inches in diameter.

Potatoes have a rest period that must be broken before they will sprout. The rest period is more easily broken in small, mature potatoes.

To be sure the rest period is broken, store small seed potatoes under warm, damp conditions for 2 weeks before planting by placing them in a shady spot and covering them with moist burlap bags or mulch. The potatoes should have small sprouts at planting time.

Seed is usually more available in the spring than in the fall. Many gardeners buy extra seeds in the spring and hold it over for fall planting. For best storage, keep the potatoes in a cool, humid spot such as the bottom of a refrigerator.

Do not save your potato seeds for more than 1 year. This can cause buildup of virus diseases and reduce yield.

Planting

Plant potatoes when the soil temperature 4 inches deep reaches about 50 degrees F, or about 3 weeks before the last spring frost. In most areas of Texas, potatoes should be planted in February or early March. If planted too early, the tops can be frozen off by spring frost.

For a fall crop, plant about 110 days before the first expected frost, or mid-August in most areas. Use a hoe or stick to open a trench about 3 inches deep down the center of the bed. Drop the seed pieces 10 to 12 inches apart in the trench (Fig. 5). Step on each seed piece after dropping it to ensure good contact with the soil.

Cover the seed about 3 inches deep. If covered too deeply, the plants will be slow to break through the soil and will be more subject to disease and seed decay.

Figure 5. Drop the seed pieces 10 to 12 inches apart in the trench.

Fertilizing

The plant must have adequate moisture and fertilizer when the tubers are forming. This usually occurs when the plants are 6 to 8 inches tall. Apply 1 cup of fertilizer for each 30 feet of row beside the plants when they are about 4 inches tall.

Watering

During growth, keep the soil moisture supply constant. Water the fertilizer into the soil, especially on sandy soils.

Moisture stress followed by irrigation or rainfall can cause growth cracks and second growth (Fig. 6). If the rainfall is accompanied by hot weather, the rest period of developing tubers can be broken and can cause the tubers to sprout in the soil. Too much water enlarges the pores on the tubers and makes them rot easily in storage.

Figure 6. Moisture stress followed by watering can cause growth cracks and second growth. Too much water causes enlarged pores on the tubers.

Care during the season

All tubers produced on a potato plant arise from above the seed piece. Because the seed piece is planted only 3 inches deep, soil must be pulled toward the plant as it grows (Fig. 7). This gives the tubers a place to form.

Figure 7. Because all tubers produced on a potato plant come from above the seed piece, the soil must be pulled toward the plant as it grows.

Some gardeners use thick mulch for this purpose. Potatoes formed in soft mulch often are smoother and have a better shape than those grown in soil. This is especially true if the soil is heavy.

As the potatoes enlarge, they must be protected from sunlight or they will turn green. Apply a thick layer of mulch when the plants are 8 to 10 inches tall to block sunlight, reduce soil temperature, and increase yield and quality.

Potato plants usually produce flowers and sometimes produce fruits (Fig. 8). The fruits bear the true seed of the potato plant. They look like small tomatoes but cannot be eaten.

Figure 8. Potato plants usually produce flowers and sometimes produce fruits.
Potato plants do not cross with tomato plants.

Insects

Many insecticides are available at garden centers for homeowner use. Sevin is a synthetic insecticide; organic options include sulfur and Bt-based insecticides. Sulfur has also fungicidal properties and helps in controlling many diseases.

Before using a pesticide, read the label and always follow cautions, warnings, and directions.

Diseases

Potatoes are troubled by several diseases. Treating seed pieces with a fungicide before planting can be helpful.

Check the plants daily and treat them with an approved fungicide if diseases appear. Neem oil, sulfur, and other fungicides are available for use. Always follow label directions.

A good rotation program is an effective way to control most potato diseases. If possible, do not plant potatoes in the same place more than once each 3 years. Do not follow or precede potatoes with eggplant, okra, pepper or tomato.

Seed piece treatment is especially important if your garden is too small for adequate rotation.

Harvesting and storing

Potatoes are ready to harvest when the tops begin to die and the potato skin becomes firm. The skin is set when it does not scrape easily when rubbed with the thumb. Skin set can be speeded by cutting back the tops of the plants.

Most of the potatoes should weigh 6 to 12 ounces at harvest. You can harvest small “new potatoes” during the growing season by carefully digging beside the plants with your fingers.

To harvest potatoes, dig under the plants with a shovel or spading fork. Keep the pitchfork 8 to 10 inches away from the plant to prevent cutting the potatoes. Raise the plants and shake away the soil.

Potatoes should be dug when the soil is moist. If it is too wet, the soil will stick to the potatoes. If too dry, dirt clods will bruise the potatoes.

Pull the potatoes from the vines and handle them carefully to prevent damage; damaged potatoes do not store well.

Allow the potatoes to dry; then store them in a cool spot with plenty of air movement. Most potato varieties are ready to dig 95 to 110 days after planting.

After the potatoes are dug, place the tops in the compost pile. The spring potato crop often can be followed with a summer crop such as southern peas.

Serving

Peel away the green areas on potatoes before cooking. For suggestions on how to prepare and serve potatoes, contact your county Extension agent.

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Potato

Potato is a cool-season vegetable that ranks with wheat and rice as one of the most important staple crops in the human diet around the world. The white potato is referred to as the “Irish potato” because it is associated with the potato famine in Ireland in the 19th century. Potatoes are not roots but specialized underground storage stems called “tubers.” Maximal tuber formation occurs at soil temperatures between 60° and 70°F. The tubers fail to form when the soil temperature reaches 80°F. Potatoes withstand light frosts in the spring and can be grown throughout most of the country in the cooler part of the growing season, but they prefer the northern tier of states for maximal yield and quality.

Recommended Varieties

There are more than 100 varieties of potatoes. White-skinned (actually very light brown) and red-skinned varieties with white flesh are the most common in home gardens. Some russets and yellow-fleshed types are also grown. Russet Burbank is the most important commercial variety produced in the United States, but the weather over most of the country is too warm and the moisture fluctuation too great for the production of smooth tubers and good yields. Common garden varieties offer better taste, texture and cooking quality for home use anyway.

The following varieties are well adapted to a variety of conditions. If possible, use northern-grown seed potatoes that are certified disease free.

Early

Irish Cobbler (light brown skin; often irregularly shaped)

Norland (red skin, smooth, resistant to scab)

Midseason

Red Pontiac (red skin, deep eyes)

Viking (red skin, very productive)

Late

Katahdin (light brown skin; smooth; resistant to some viruses, verticillium, bacterial wilts)

Kennebec (light brown skin, smooth; resistant to some viruses, late blight)

Green Mountain is an old semi-rough white variety noted for its great taste. Due to a fairly high number of misshapen tubers, it has all but disappeared from commercial production. For dependable production in all seasons and the greatest-tasting baked potato ever, Green Mountain is worth the effort to find certified seed.

Yukon Gold is the most famous of the new wave of yellow-fleshed varieties now available. Long popular in Europe, these have good flavor and moist flesh, which many people claim requires less of the fattening condiments required by dry-as-dust Russet Burbanks. Yukon Gold is a very early bearer of large, round, attractive tubers with a hint of pink around the eyes. Many grocery stores around the country now feature some name-brand version of “golden” potatoes, usually this variety. If the flavor of these market potatoes suits you, look for seed of Yukon Gold.

When to Plant

Potatoes are among the earliest vegetables planted in the garden. Early, midseason and late varieties all may be planted in March or early April. Planting too early in damp, cold soils makes it more likely that seed pieces rot before they can grow. Potatoes planted in March also may be frozen back to the ground by late frosts. Plants usually recover fully, but the blackened shoots are always demoralizing to the gardener. Medium-early plantings, when soils have dried and warmed, may do as well as extremely early, winter-defying plantings. Midseason and late varieties may be planted as late as the first of July. Late potatoes are best for winter storage.

Spacing & Depth

Potatoes are started from “seed pieces” rather than from true seed. These seed pieces may be small whole potatoes or potatoes that are cut into 1-1/2 to 2 ounce pieces. Plant the pieces soon after cutting. Be sure that there is at least one good “eye” in each seed piece. Some garden centers and seed suppliers sell “potato eyes” that weigh less than an ounce. These may be too small for optimal production. Small, whole, certified seed potatoes are often the best choice for home gardeners.

Plant seed pieces 10 to 12 inches apart and cover in a furrow between 1 and 3 inches deep. Space rows 24 to 36 inches apart. The 24 inch spacing is often beneficial because the plants shade the soil and prevent high soil temperatures that inhibit tuber development.

“Straw Potatoes”

Potatoes grown by a special cultural method in that they are not hilled or cultivated after planting are called “straw potatoes.” The seed pieces and rows should be spaced the same as for conventional cultivation, but the seed pieces are planted at the soil surface. Place loose straw 4 to 6 inches deep over the seed pieces and between the rows. Potato sprouts should emerge through the straw cover. Cultivation should not be necessary. Pull any weeds that manage to emerge through the straw cover and add more straw through the season if decomposition starts to thin the layer. Harvest by carefully removing the straw and picking up the tubers that lie on the soil surface. In addition to weed control, strawing has several other advantages. The straw keeps the soil temperature more uniform and about 10°F cooler, reduces water loss and results in better-shaped tubers. It is usually more rewarding to straw late varieties than early ones because there is a longer period for tuber development. Many gardeners who grow potatoes for competition in exhibits and fairs use the strawing method because the potatoes are of excellent size, color, shape and smoothness.

Care

The soil should be fertile and well drained. Clay soils should be improved with organic matter and plowed deeply in the fall. If space allows, a cover crop such as clover, buckwheat or winter rye grown in the potato bed the year before potatoes are planted improves soil structure, organic-matter content and subsequent potato production.

Mulch is usually beneficial in growing potatoes. After the potato plants have emerged, organic mulch can be applied to conserve moisture, help keep down weeds and cool the soil. Some gardeners cover rows of early potatoes with clear plastic film at planting to warm the soil and promote early growth when the soil temperature is low. When the plants emerge, remove the film to allow the plants to grow unrestricted.

After the potatoes break the surface of the ground, gradually build up a low ridge of loose soil by cultivation and hoeing toward the plants. This ridge, which may become 4 to 6 inches high by summer, reduces the number of “sunburned” (greened) tubers. The object of potato cultivation is to eliminate competition from weeds, to loosen and aerate the soil and to ridge the row. Misshapen potatoes develop in hard, compact soil. Use extreme caution when hoeing near potato plants because developing tubers are easily cut and ruined.

Irrigate to assure uniform moisture while the tubers are developing. A uniform moisture supply also helps to cool the ground and eliminate knobs caused by secondary growth.

Harvesting

Harvest potatoes after the vines have died. Handle as gently as possible during harvest. Because the tubers develop 4 to 6 inches beneath the soil surface, a shovel or spading fork is a useful tool for digging potatoes.

Potatoes for use in early summer (“new potatoes”)may be dug before the vines die (usually in July). When the potatoes reach 1 to 2 inches in size, you may wish to dig a few hills to use for soup or to cook with creamed peas or to butter and roast.

Late potatoes are usually dug in August or early September. They keep in the garage or basement for several weeks in their natural dormancy. Store over the winter in a dark room at a temperature between 38° and 40°F with high humidity. Check periodically for spoilage. Temperatures below 38°F cause internal damage to the tubers.

Common Problems

Flea beetles are shiny, usually black, beetles that often are not seen due to their small size (1/16 inch) and ability to jump quickly from plants when disturbed. They attach cabbage, Chinese cabbage, eggplant, radish, spinach, sweet corn, turnip and potato. Flea beetles scratch holes or leave white streaks in green foliage in late spring. Intense feeding results in wilting and dying of leaves and decreased yield.

Leafhoppers are up to 3/8 inch long, green in color, and wedge-shaped. They may migrate from one area of garden to another and hop away in large numbers when foliage is disturbed. They attack bean, carrot, cucumber, Irish potato, and muskmelon. Symptoms of leafhopper damage includes curled or crinkled foliage and “hopper burn” (caused by leafhoppers’ feeding, indicated by brown edges on leaves).

Questions & Answers

Q. Should I save some of my potatoes for seed?

A. No, unless you are saving seed of an heirloom variety not commercially available. Saving your own seed potatoes can lead to a buildup of viruses and diseases. Whenever possible, plant seed potatoes certified to be free from certain viruses and diseases.

Q. My potato plants flowered and formed green fruits that resemble small tomatoes. What are they?

A. These small seed balls are the fruits that contain the true seeds. They are not edible. Except for breeding purposes, growing potato plants from the true seeds in these fruits is a troublesome and unrewarding exercise.

Q. What causes green skin on my potatoes?

A. The green areas on tubers develop where the potato was exposed to the sun. This condition occurs when the potatoes were not planted deeply enough or not covered with straw. The green portions taste bitter because they contain a moderately poisonous alkaloid. These green areas should be cut off and discarded. Exposure of potato tubers to fluorescent light or sunlight causes greening during storage.

Q. How should potatoes that are cut into seed pieces be cured?

A. They can be cured by holding them for a week at 60° to 65°F with high humidity (85 percent or higher). This treatment is of questionable value for the home gardener.

Q. Can I make chips from homegrown potatoes?

A. Yes. Almost any potato variety can be used to make chips when the potatoes are freshly dug and starchy. Commercial chips are made from selected varieties that are naturally high in solids, carefully handled and properly stored to preserve starch and avoid buildup of sugars. Chips made from potatoes stored at low temperatures for long periods are brown or have a dark ring because they contain excessive amounts of sugar.

Q. Can I use grocery store potatoes for planting?

A. Probably not. They may have been treated with a sprout retardant, in which case, they will not grow. Even if they are sprouting, they have not been inspected and certified free of disease. While results occasionally may be acceptable, the risk of introducing a nematode, disease, or other pest is much higher than from quality-certified seed potatoes.

Selection & Storage

Potatoes are the most popular vegetables in the United States. Although there are more than 100 known varieties, about six varieties make up the entire commercial market. Home gardeners are able to taste some of the wonderful flavors and textures unknown to the average person. Some varieties are not considered marketable because they do not ship well or are prone to disease.

Potatoes are generally classified as round red, round white, oblong white and yellow-fleshed. New potatoes are any variety of freshly dug young potato that hasn’t been stored. Potatoes can be harvested at any stage of development from marble-size to full maturity. Potato size at maturity depends on the variety planted. Potatoes should be firm, free of soft spots, and free of disease when harvested.

Even stored under the best conditions, potatoes lose some quality the longer they are stored. For best results, store in a cool, dark place with good air circulation. Do not refrigerate potatoes. Cold temperatures convert starch to sugar, giving potatoes an uncharacteristic sweet taste. The sugar caramelizes during cooking producing brown potatoes and an off flavor. Potatoes can be stored for a week or two at room temperature (65 to 70 degrees) with good results.

If potatoes start to sprout, they can still be eaten. Remove the sprouts and discard. If the potato is still firm, it is good to eat. Shriveled, wrinkled, sprouting potatoes should not be eaten. Green-skin potatoes have been exposed to too much light. A mildly toxic alkaloid called solanin forms in the skin. The green skin can simply be peeled away. Although the remaining potato is safe to eat, it will not be at its best.

Nutritional Value & Health Benefits

Potatoes were once considered just a dietary source of starch. Although potatoes do contain a goodly amount of carbohydrate (starch and sugar) they are also a storehouse for many vitamins and minerals. With the exception of vitamin A, potatoes have at least some of just about every nutrient, including fiber. Potatoes are relatively low in calories, unless they are eaten with butter, sour cream and mayonnaise.

Nutrition Facts (1 oblong white, baked, about 2″ x 4-3/4″)

Calories 145
Protein 3.06 grams
Carbohydrates 33.63 grams
Dietary Fiber 2.34 grams
Calcium 7.80 mg
Iron .55 mg
Magnesium 39.00 mg
Potassium 609.96 mg
Phosphorus 78.00 mg
Vitamin C 19.97 mg
Niacin 2.17 mg
Folate 14.20 mcg

Preparation & Serving

Potatoes can be boiled, fried, steamed, grilled or baked. All potatoes should be cooked or placed in water immediately after peeling to prevent discoloration. To peel or not to peel is generally a result of the preparation method or personal preference. The exceptions are thin-skinned new potatoes, which should not be peeled.

Potato varieties should be selected based on their use in a recipe. New potatoes are moist and waxy and are best for steaming, boiling and in salads. Oblong mature white potatoes are rather dry and starchy. They are the most popular french-fried potato and they are great for baking and mashing. Round red potatoes have a rather waxy texture making them ideal for boiling and mashing. Round white potatoes are thin-skinned and hold their shape in salads as well as boiling and roasting. Yellow-fleshed potatoes are good for steaming, roasting, and mashing.

Fresh garden herbs that enhance the flavor of potatoes include basil, chives, cilantro, dill, fennel, lovage, marjoram, oregano, parsley, rosemary, sage, tarragon and thyme.

Home Preservation

Potatoes do not freeze, dry or can with good results. For long term storage of late fall crops, store at temperatures of 45 to 50°F. After harvesting, place in the sun for two to three hours to dry, brush off the soil, do not wash until ready to use. If storage temperatures are too high, potatoes tend to soften and sprout. Store in a dark place to prevent greening and layer between sheets of newspaper so if one spoils it will not spread to the whole lot.

Recipes

New Potatoes with Garlic and Herbs

Using a vegetable brush, gently scrub potatoes under cold running water. Do not peel the thin skin away. The fresh herbs and garlic compliment the potato flavor rather than overwhelm it. Use any fresh herb available to you.

8 to 10 small new potatoes
2 tablespoons olive oil
3 cloves garlic, peeled
1/4 cup fresh parsley, dill or thyme leaves
1 teaspoon each, freshly ground pepper and salt

1. Cut potatoes in half, then quarters then across quarters into cubes (about 2 cups). Place in a colander, and rinse well under cool running water. Place in a saucepan with enough water to just cover the potatoes. Bring to a boil, reduce heat, cook for 15 minutes or until potatoes are tender.

2. Meanwhile, chop the parsley together with the garlic until finely minced.

3. Drain the potatoes and toss with olive oil. Add parsley/garlic mixture, salt and pepper and toss until combined. Makes 4 servings.

Potato Plants Not Producing: Answers To Why No Potatoes On Plants

There is nothing in the world as disappointing as digging your first lushly leafed potato plant only to discover that your potatoes produced leaves but no crop. Low potato yields are a common problem of well-meaning, but inexperienced gardeners who over-fertilize their crops in hopes of a big potato payoff. Fertilizing potatoes is a delicate walk between too much and too little — both situations could result in no potatoes on plants.

Reasons for Potato Plants Not Producing

Gardeners often go wrong when preparing their potato beds because they neglect to test the soil’s fertility before adding fertilizers or other organic material. A moderate level of fertility is desirable at planting time, especially if this isn’t the first time you were left asking yourself why no potatoes formed below those lovely, dark green potato leaves. When nitrogen, potassium and phosphorus are in balance in moderate to high amounts, your bed is primed for planting.

During the first phase of potato growth, a lot of leafy vegetation is required so that in later stages the plant can make plenty of food to store underground in structures that will swell into potatoes. A balance of nitrogen, potassium and phosphorus promotes the rapid development of healthy leaves and roots that reach deep into the soil to provide your potato with an abundance of building blocks and water.

Where many gardeners have gone wrong when their growing potato plants are not producing is around bloom time, when the potato tuber begins to bulk. Excessive application of nitrogen at this time will result in no potatoes on your plants or low potato yields. If your plants were planted in a properly fertile soil and given a side dressing of about an ounce of 10-10-10 fertilizer each when they were 8 to 12 inches tall, no further feeding is necessary.

Why No Potatoes – Clues in Potato Leaves

It may be hard to tell what’s going on beneath the soil, but your potatoes will give you clues about their overall health. If you watered your potatoes deeply and often, and no black rot is making its way up the stem, the potato canopy can very reliably indicate the availability of nutrients in the soil. If caught early, you may be able to correct the issue and still harvest some potatoes.

Over-fertilized potatoes, besides having lots and lots of very green foliage, may have leaves that emerge deformed or that roll up under stress because they’ve put everything they had into making leaves at the expense of roots. The canopy of under-fertilized potatoes, on the other hand, turns yellow before browning and dying. Younger leaves may emerge pale green or even yellow with green veins, and may grow slowly or appear smaller than normal.

Use these clues to adjust your fertilizer program as necessary, giving an extra ounce of 10-10-10 fertilizer to yellowing potato plants and withholding any further fertilizer for those lush, over-fertilized plants.

Flowering doesn’t mean potatoes are harvest ready

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Question: Help! I’ve planted four kinds of potatoes. Some are flowering, some are not. Does flowering mean that new potatoes are ready to harvest? How do I know when each kind are ready to harvest? I can’t remember what I’ve planted where, so it is really confusing.

Answer: Do you know which varieties you planted? Each type of potato has a different “days to maturity” number. For example, Yukon Golds are 70 to 90 days to maturity. This makes them “early season” potatoes because they are ready earlier than some. A “late season potato,” such as heirloom fingerling types, takes about 110 to 135 days to maturity. If you recall when you planted your spuds, you can kind of predict their readiness. But it is always best to check directly, by hand.

For example, I try and plant at least some of my potatoes by the end of March. It is now the end of June. That’s 90 days of growing that has happening already. So it is time to go out and check the early-season varieties such as Yukon Gold and Viking Purple that I planted in late March.

I also planted heirloom Rose Finn, in early May. These are late season potatoes that need 110 to 135 days to mature. So far, they’ve only been growing about 50 days. They’ll need another couple of months at least to get to maturity.

If you can’t remember or don’t know what you’ve planted, grub around the soil below the vines with your hands periodically to feel for tuber development. Young or new potatoes can be hand harvested as soon as they develop. These are a real summer treat, not available at the grocery store.

Flowering just means that the vines are mature enough and have enough leaf area to start forming tubers. It doesn’t mean the tubers are ready to harvest. Until they reach mature size, your potatoes should be watered regularly though the summer, from 1 to 3 inches of water per week, as needed.

Cover the plants with soil and other organic material to protect the tubers as they form, from sunlight and greening of the skin. The greening is chlorophyll, which is not harmful in itself but may be accompanied by a high concentration of a toxic compound called solanine. Mounding soil around growing potato vines also makes harvest easier and may prevent water loss.

To toughen up your potatoes for storage before harvest, do not water them much after they flower. Let the vines die all the way back before you harvest them.

Clean your potatoes before storing them. You need only brush the soil off potatoes grown in coarse, sandy soil. But if you grow potatoes in fine, sticky clay soil, your potatoes may need washing. If so, be sure the potatoes are completely dry before placing them in storage.

Keep in mind that red potatoes, while great for eating fresh, don’t keep as long as yellow or white varieties. Thin-skinned potatoes like reds don’t last as long in storage as those with thick skins, such as Russets. Personally, Yukon Gold is my favorite all-around potato variety to grow at home. It yields and stores well, is great harvested as a new potato and bakes or boils well, without getting mushy. Plus, it has a great flavor and wonderful buttery color.

To make your potatoes last longer in storage, cure clean, dry potatoes for a week to 10 days in moderate temperatures and high humidity. Ideal conditions for curing are about 65 degrees with a relative humidity ranges from 85 to 95 percent. Keep them under these conditions for a week to 10 days to harden off and heal any injuries caused during harvest.

Before storing them for the long-term, sort and separate out the shovel-injured and diseased spuds. Eat these first, as they don’t last long. They also may spread spoilage or disease microorganisms to uninjured potatoes.

After the curing period, store the perfect spuds in a cold, dark environment with moderate humidity. Store your best tubers in a dry room with constant temperature of 35 to 40 degrees and moderate humidity. Make sure to keep them dark, as light will turn them green and make them unfit for table use. Discard potatoes with an excessive amount of greening.

Under these conditions, well-matured potatoes will stay in good condition for seven to eight months. When storage temperatures exceed 40 degrees, potatoes should keep for two to three months, but sprouting and shriveling may occur. If they sprout and shrivel, save them for planting in April.

Carol Savonen is a naturalist and writer. She is an associate professor emeritus at OSU and tends a large garden in the Coast Range Hills west of Philomath with her husband and dogs. She can be reached at [email protected] or c/o: EESC, 422 Kerr Admin. Bldg., OSU, Corvallis, OR 97331.

Troubleshooting: Why Are My Potatoes So Small?

You’ve been waiting forever for your potato plants to finally die down.

For months, you’ve been fantasizing about harvesting pounds and pounds of potatoes, more than enough to supply your family for a few months; maybe even keep them going through the winter, as potatoes are one of the best survival foods for the cold months.

You imagined potatoes the size of your foot, excellent for baking with!

As you rake the dirt to the side and uncover your incredible harvest, you find small, golf-ball sized potatoes….

What on earth happened?

Why Are My Potatoes So Small?

If your potatoes are uniformly small, there was a crop-wide issue. If you had a few small ones per plant but otherwise large potatoes, then this situation is actually quite normal. A standard harvest will have one or two very large potatoes, several middle or standard sized ones, and a few little or tiny ones. Not all of the potatoes will be huge, especially in a home gardener’s plot.

If you had a crop-wide potato yield problem, you should recollect all of your gardening practices from planting to harvest.

  • Did plants receive enough water?
  • Were they grown in a very hot season?
  • Were the potatoes planted in full sun?
  • Did you experience pest or disease issues?
  • Did you overcrowd the plants?
  • Were the seed potato varieties known for growing large tubers?
  • Did you harvest them too early?
  • Did you give them too much fertilizer?
  • Was the soil rich and was the pH ideal?

All of these will directly affect the growth of the potato plants and the tubers that they produce.

Did You Grow Your Potatoes in Towers, or In the Summer Heat?

Potato grow bags, potato cages, growing towers, and much more are all the rage in potato gardening currently. However, what those people FAIL to tell you is that potatoes are sensitive to heat and drought during tuber production.

Yes. Those same people who gush about grow bags and towers are not giving you the information you need. Potato grow bags like the ones below are more than capable of producing a GREAT harvest, but they require more water than a potato bed within the ground. In addition, the containers should be given a blanket of straw. Straw will keep moisture in, and keep the heat out. If you have a cooler fall with a good length of time before frost, try starting your potatoes 3 months before the first frost. You might find more success with this than spring growing.

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Did You Offer Enough Water?

Tubers require adequate water when they begin to bulk up. Without enough water, they will not grow very large. The tubers must not be competing with the foliage for available water; if they are, the foliage will be given priority. Make sure that the potato plants are receiving closer to 2″ of water per week after flowers bloom. Use straw to help hold moisture in.

Did You Feed Your Potatoes Too Much Nitrogen Fertilizer?

If you use fertilizer, you may notice a sudden growth among the foliage. This might seem like an excellent sign; it may even lead you to believe that the potatoes needed it. However, potatoes will send up lots of green foliage when given excess nitrogen; but this can be a bad thing.

The plant will dedicate its energy towards foliar growth rather than tuber growth.

Instead, offer the potatoes fertilizer that is lower in nitrogen. Root vegetables require more potassium and phosphorous than most other plants, and fertilizers are not created equal. There is no “one size fits all”, as some plants will get too much of one nutrient. In this case, it would be potatoes receiving too much nitrogen.

Did The Potatoes Grow In Full Sun for a Full Season?

If the plants are to produce large mature tubers, they must have the ideal growing conditions to generate and store energy within their potatoes. Potatoes require full sun, not a shaded location. The more shade they receive, the less growing and energy production they will accomplish.

They must also be allowed to grow for a full cycle; meaning, they must grow from seed tuber until the plant’s natural death (or shortly before in cooler growing zones.) If you harvest the plant too early, the tubers will not have had sufficient time to mature.

Grow potatoes in small spaces with 7 easy steps

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If your garden is more “postage stamp” than “grand estate,” you may think you don’t have room to grow a hearty crop of spuds. But when you want to grow potatoes in small spaces, know that it isn’t as difficult as you may think. Yes, if left to sprawl, potato plants do take up a lot of real estate, but if you grow potatoes in bins instead of in the ground, it’s easy to get a full-size harvest in minimal space.

Here are 10 steps to grow potatoes in small spaces:

Step 1: Pick the right variety

Start your tater-growing adventure by deciding what variety of potato to grow. Russets are great for baking and storing, fingerlings are perfect pint-sized spuds, and heirloom varieties come in a rainbow of colors and textures (the potato in the feature image is an heirloom called ‘All Blue‘). No matter what type you choose, be sure to purchase certified disease-free seed potatoes from a reliable source.

Step 2: Make the cut

Officially speaking, seed potatoes aren’t seeds at all. They’re fully developed potatoes that are cut into pieces and planted like a seed. Use a clean, sharp knife to cut each tuber into several sections, being sure each section contains at least one “eye” and an inch of flesh. Let the cut potatoes rest for 24-48 hours before planting. This rest period enables the cut area to callous over and helps keep soil-borne diseases from rotting the tuber before it can grow.

Cut seed potatoes into small pieces before planting. Make sure each section has at least one “eye.”

Step 3: Find a home

Thankfully, potatoes aren’t overly particular about where they grow, but they do produce best where they receive a minimum of six to eight hours of direct sun. Select your planting site accordingly.

Step 4: Set up the bin

Growing potatoes in a bin may just be one of the most fun things you’ll ever do in the garden. It’s easy, and the plants are surprisingly productive. Make a three- to four-foot-wide cylinder of box wire or chicken wire fencing. I like to use fencing that’s four feet tall. Line the inside of the wire bin with a layer of newspaper about ten sheets thick. Fill the bottom eight inches of the bin with a 50/50 blend of compost and potting soil.

Growing potatoes in a wire bin is easy and fun!

Step 5: Plant the taters

Put the cut seed potato sections on top of the compost/potting soil blend. How many seed potatoes you add will depend on the bin’s diameter. When I grow potatoes in small spaces using this technique, I usually put eight to ten pieces per bin. Then, I cover the seed potatoes with another three inches of the potting soil/compost mix. Over the coming weeks, as the plants grow, fill the rest of the container little-by-little with the compost mix until it reaches the top. This technique serves the same function as “hilling” does – it allows more stem area below ground for potato production.

Step 6: Maintenance

The only negative when you grow potatoes in small spaces like this is the constant need to water. Potatoes need to be consistently moist, so a daily dousing during summer’s heat is an absolute must. If Colorado potato beetles become problematic, cover the plants with floating row cover.

Step 7: Digging your potatoes

The potatoes are ready to harvest after the plants turn completely brown and die. Allow the tubers to sit in the ground two to three weeks beyond the death of the plants. This resting period is necessary to harden off the skins and make them better able to withstand long periods of storage. To harvest, simply open the wire cylinder and dig through the soil with your hands to uncover the spuds.

Are you ready to grow potatoes in small spaces? Tell us about it!

Potatoes 101: How to Get Great Yields with Successful Techniques


Sara harvesting early new potatoes from her hoophouse at Sandiwood Farm

Potatoes are a simple, fun crop to grow and can help you eat local year-round thanks to their impressive shelf life. In addition to choosing the right varieties for your needs, it’s also important to choose a successful growing method.

You can find information about all sorts of different techniques on the internet these days, from growing in stacked wooden boxes to wire cages filled with straw. But a lot of these methods just aren’t worth their salt and can result in disappointing yields, even with extra love and care. We’re all about helping you succeed, so in this article we’re just going to focus on methods that really work.


Monique hilling potatoes in the High Mowing Trials field

Hills. This is the traditional method that our parents and grandparents used, and it’s the most practical for large plantings. To succeed, you need to prepare an area by tilling or turning and raking the soil so that it’s soft and loose. If your soil hasn’t been amended recently, you’ll want to mix in some compost as well. Once the soil is prepared, dig long, straight trenches 3-5 feet apart (more space means more potatoes), then space your seed potato pieces about 12” apart in the trenches. Cover the seed potatoes with about 4” of soil, then water in well. When the potatoes have sprouted and grown foliage about 8” tall, you should begin “hilling” the plants by mounding the fluffy soil on either side of the trenches up around the stems of the plants. As long as there is some foliage sticking out they’ll keep growing, and the more you hill, the more potatoes you’ll get. It’s important to keep hilling throughout the season, since any tubers lying close to the soil surface will turn green if they become exposed to sunlight.

You can mulch your hills with straw if you like, which conserves water and makes it harder for potato beetles to move around, but it does get in the way when hilling. If you use straw, leave it in flakes rather than fluffing it up—this way it makes a solid weed barrier and can be gathered and stacked in a neat pile while you’re hilling.


Potatoes grown in raised beds produce the highest yields thanks to the large amount of soil held around the roots

Raised Beds. Growing potatoes in raised beds, whether they’re simply mounded or have actual frames, is one of the easiest and most productive methods. You don’t need to till every year, which is better for maintaining soil structure and health, and you can plant earlier since you don’t need to wait to till before planting. Since potatoes produce best in cool soil that is 40-60°F, most people will have better results with crops planted early in the season, though this is more flexible in cool climates.

To succeed, start by mixing some compost into the soil, then dig shallow trenches about 6” deep and 2-3 feet apart in your raised beds, plant your seed potatoes in the trenches about 10” apart, then cover with 4” of soil. Just like with planting in the ground, you should begin hilling the plants when they get about 8” tall, and continue hilling as the plants grow to give the tubers plenty of room to size up.

To harvest from hills or raised beds, wait until about one week after the plants have completely died back, then pull them up by the stems and remove any potatoes that are attached to the roots. Once the plants have been removed from the bed, you can use a spade or garden fork to dig up the rest of the potatoes. Alternatively, you’re less likely to accidentally spear your spuds if you invite some friends over to help you sift through the soil by hand. It’s a dirty job, but if you feed your helpers in return (or remind them that soil microbes are natural anti-depressants), they won’t mind so much.

Potatoes in GrowBags

Containers, Stacking Boxes or GrowBags.

One of the biggest advantages of growing in pots, boxes or bags is the ease of harvest – you just dump out the container and collect your potatoes. The yields from containers can be as good or better than from hills or raised beds, since there’s a large volume of soil held around the plants, and they grow vertically in this system, which also takes up less space. To succeed, select a large container (3-10+ gallons) with plenty of drainage holes, and add about 3” of potting soil. Place your seed potatoes in the bottom of the container, then cover with 4” more soil and water in. Add more soil to the container as the plants grow, until the soil is 1” below the top rim of the container. You can alternate “hilling” with potting soil and garden soil to keep cost down, just don’t use only garden soil (see below), and be sure to water your containers every morning that it isn’t raining.

Methods I Do Not Recommend Because They Stress the Plants & Reduce Yields:

  • Planting in straw (I find that the plants dry out, but this may work in high-rainfall areas)
  • Planting in wire cylinders full of straw, compost or soil (there is too much airflow so the plants dry out, resulting in undersized tubers)
  • Planting in plastic bags or other containers with poor drainage and airflow. Food-grade plastic tubs with drainage holes can be used, but clear and dark-colored tubs tend to heat the soil too much and can reduce yields
  • Planting upside down, grafted to tomato plants or other boutique methods that are more like fun science experiments than successful production techniques


It’s important to control Colorado Potato Beetle larvae as soon as you see them. Just drop them into a bucket of soapy water (or squash them).

5 Common Mistakes to Avoid:

Starting Too Late. If you’re located anywhere except the cool North or mountain states, there’s not much point in planting potatoes in June. The soil is already too warm and yields will be disappointing. However, you may still be able to produce a fall crop by planting in an area with afternoon shade, where the soil stays cooler, and fall crops may avoid the worst damage from Colorado Potato Beetles.

Letting Plants Dry Out. This is an issue in areas with sandy soil and in hot environments like containers, rooftops and urban heat islands. Water thoroughly every morning in these situations, and hire a plant-sitter if you’ll be going away. Plants that have wilted will have reduced yields.

Using the Wrong Soil. Generally potatoes grow best in deep, loose, loamy soil that is not too rich – 2 parts garden soil to 1 part compost is a good mix for hills and raised beds. If your soil is compacted or you till too shallowly, your plants won’t have enough soil to grow in and yields will be low. If you plant in containers, you need to use potting soil because garden soil hardens in pots, making it harder for tubers to form.

Not Enough Drainage. All potatoes prefer good drainage, so it’s best to choose a spot that doesn’t flood, even in rainy seasons. This is unavoidable in some years, but drainage ditches, raised beds, containers or aggressive hilling can keep the plants above water in extreme situations.

Too Many Seed Potatoes. The amount of loose soil you provide, not the number of seed potatoes you plant, is the main factor that will limit yields. Crowding the plants will generally result in lower yields, not higher ones, so give each potato piece the space and soil it needs to thrive.

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