Growing potatoes in the garden is easy!
Every culture that has cultivated the potato has found that all that the potato requires is good soil and abundant sunlight to produce a heavy yield of nutritious tubers.
The potato is a carbohydrate and nutrient rich food only notably lacking in calcium, vitamin A and Vitamin D. Many people have subsisted on a diet which combined potatoes with dairy products, to sustain good health indefinitely.
The potato is a member of the nightshade family native to South America in the mountainous areas of southern Peru and north-eastern Bolivia. People there have cultivated the potato as a basic staple for perhaps as long as seven thousand years.
The Nazca and Chimu civilizations, which predate the Inca, depicted potato preparation on their pottery. To the Incan empire the potato was an important staple. A dehydrated preparation called "Chunu" could last up to 10 years to provide excellent insurance against crop failure.
Spanish conquistadores noted consumption of Chunu amongst the Incan miners that they enslaved. They began to provision their treasure ships with potatoes for the return to Spain. As potatoes were rich in Vitamin C, the Spanish took note that the potato prevented Scurvy.
By the 17th century the potato was undergoing widespread cultivation in Europe, first as an animal feed and then, begrudgingly, as a staple for the lower classes. Many people thought that the potato was unfit for consumption as it was a member of the nightshade family. Others distained them as lowly, as the tubers grew from the earth.
Still, the potato was capable of growing an unprecedented amount of nutritious food per acre and was good insurance against famine. In some areas, most notably in parts of France, Prussia and Ireland, potato cultivation was encouraged by several governments. By the 19th century, potato cultivation enabled a population explosion which literally helped to feed the industrial revolution.
But when relied on exclusively as in Ireland, the poor became so dangerously dependant on the potato that when the crop failed in successive years due to the Phytophthora blight it resulted in the infamous Irish Potato Famine.
Today the potato can be found in cuisine and grocery stores around the world and can be very easily grown in your garden. In its native South America there are many different species of potatoes with notable differences, but nearly all of the potatoes grown outside of South America are of the species "Solanum tuberosum ssp. tuberosum"
Even within this species, a wide variety of cultivars have been developed with differing qualities. Some are waxy, some are starchy, some make good fries some are better boiled and mashed. A potato gardener may wish to grow several different varieties for different uses.
For example, for 2011 I am growing five different varieties. Banana Fingerlings are a favorite among chefs and gourmet markets, with yellow, banana-shaped, waxy-type tubers that have a firm texture and have a wonderful flavor baked, boiled and steamed. The French Fingerling is a gourmet quality fingerling with satin red skin and yellow flesh with an interior ring of red when cut across. The Russet potato is a famously starchy family of cultivars from which French fries are made. Every baked potato in a restaurant is a Russet. German Butterball and Yukon Gold potatoes are excellent mashed or fried golden brown. They make good potato salad as well.
All of these potatoes I purchase online as seed potatoes from Ronniger's Potato Garden. Local farm stands are also a good place to get seed potatoes. Any source should be selling "certified seed" which will be ensured to be disease free. Seed Potatoes can also be taken from last year’s crop but should not be planted in a location where potatoes or any other member of the nightshade family was planted the year before.
I receive a pound of each of my seed potatoes in early April. It is usually still too cold to plant the seed potatoes at this point, as optimum soil temperature for beginning growth ranges from 50 to 70 degrees Fahrenheit. Soil that is too cold or too wet can cause the seed potatoes to rot.
During this time I prepare the potato beds prior to planting. Ronniger's advises,
"Good potato soil will be well drained and, at the same time, able to retain moisture. Sandy loam is ideal. Gardeners can get by with a width of 20"-26" between rows. Tighter spacing may give a uniform canopy of foliage to cool the soil in summer, while wider spacing can help alleviate stress due to drought or poor soil."
"Other than green manures, the best organic fertilizer for potatoes is good compost mixed into the soil in the fall before planting. The older the compost the better as fresh manure will cause scab in the potatoes."
Do not plant potatoes where sod or grass was grown in the previous season as the soil may contain Wireworms which feed on grass roots and can damage tubers.
The Colorado Potato Beetle is among the most widespread and destructive potato pest. Both adults and larvae feed on the leaves and stems, sometimes defoliating entire plants. Beetles overwinter in the soil, especially at the edges of the garden. Potatoes are also susceptible to number of other diseases and pests including Early Blight and Verticillium wilt. Rotating your potato crop is essential to reduce the possibility of infestation or disease. I recommend this book for good advice on controlling disease and pests.
As I wait for the weather to cooperate and to be both uniformly dry enough and warm enough to plant, I set my seed potatoes under a grow lamp that I have in the basement. Any warm sunny location will do to grow "eyes" on the potatoes. This is known as "greening" or "chitting." Ronniger's says,
"Bring the flats into a warm living space above 70 degrees Fahrenheit, and to a location where the light levels are medium in intensity. the warmth tends to stimulate the development of strong sprouts from the bud eye clusters, which, in the presence of light, remain short and stubby and are not easily broken off."
"Usually seed potatoes are exposed to light and warmth a week or two before planting. The benefits derived from greening the potatoes in this manner are not limited to merely gaining a better stand and quicker maturity of the tubers, but is claimed that a heavier yield is also likely."
Once the soil is sufficiently warmed and dry it is time to plant the seed potatoes.
"All tubers the size of a hen's egg may be planted whole. For larger tubers, cut the potato using a clean, sharp knife so that each piece will contain 2 or more eyes. Pieces should be cut with plenty of flesh around the eyes, since the plant will utilize this stored food during the first 2 or 3 weeks of growth."
"Dig a shallow trench 6" - 8" deep, 3" wide. Place the seed potatoes about 12" apart. Cover the seed pieces under a maximum of 4" of loose soil."
In approximately two weeks, depending on soil temperature, the potato plants will emerge. Note the leaf shape and begin to pull dissimilar weeds from around the young plants.
When the stems are 8" high, gently hill up around the plant with soil. This is very important. Hilling provides an area for potato tubers to develop. The bigger the hill the more room for tubers, plain and simple.
Other than keeping the plants watered and weeded, the potatoes should be maintenance free. Ronniger's has some advice about improving the soil with molasses.
"The sugar in molasses is a good way to enhance the health of potatoes and the soil by feeding and multiplying the beneficial soil microbes. Fill a 5 gallon bucket with water and add a half cup of molasses to soak for a day and a night, stirring the liquid several times that day. Apply the liquid up to 4 times during the growing season."
Some potatoes like the Yukon gold will have short growing seasons of less than 80 days, some like the Russet will have long growing seasons of up to 120 days. Every potato will have two distinct growing phases.
In the first phase the plant will put all its energy into growing the plant. At the end of this period the plant will flower. Notice the similarities between these flowers and those other nightshades in your garden: tomato, eggplant, peppers, even tobacco if you happen to have it.
After blooming the potato plant will enter the second phase of its growth. In this phase the plant will concentrate all of its energy to growing tubers. It is important not to overwater in this phase as an excess of water can cause the tubers to rot or cause a restart of plant growth.
At the end of the tuber growth phase, in mid to late summer, the plants will get wilty looking and die. The time for your harvests is about to near. RESIST the urge to revive the plants by watering!!
Leaving the potatoes in the ground for a week or two at this point is recommended for the skin on the tubers to dry. However if the forecast threatens with torrential rains at this point, dig up your tubers immediately and move them to a dry place.
If you have prepared soil and hilled well getting your tubers out should be possible with just your hands and a good pair of gloves. Using a spade can damage your tubers. You shall experience the joy shared by countless generations of peoples as your bounty piles up by the bushel!
Using a light brush remove as much excess dirt as possible without damaging the skin. Rinsing off the tubers with water is not recommended as dry skin is essential for long term storage.
It is best to store the potatoes in a cool dark place. If the tubers are exposed to sunlight they will green and produce photo toxin which is poisionous to eat. Do not store the tubers in the refrigerator as this will cause the starches in the tubers to "sugar" and become mealy.
Following these recommendations you should have plenty of potatoes to last you through the fall and into the winter.
If you have any questions about growing potatoes or anything else in your garden this year, feel free to leave me a message!
Also feel free to write me with any of your favorite potato growing tips. Misterfuffie writes,
"You put a used tire down around the plant, on top of the soil, when you plant it. As the green part of the plant grows, once it's about twice as tall as the tire, you fill the tire with dirt. this spurs the plant to grow taller. once it's twice as tall again, you put another tire down and fill it with dirt. Two is about all I do, but some folks get up to 5, which is crazy and i think would only work in areas and with cultivars that have a really long green growth phase. So once the tuber stage starts, you have this enormous root system that will bear tubers."