Potatoes

What is there to learn about potatoes? They are the old fill-up food bought in 10- or 20-pound bags and peeled and boiled for every supper, if you’re from a northern European family. With a little know-how and a bit of effort, you can grow bushels and bushels. That may be true, but this lowly vegetable is uniquely fascinating and well deserving of a few pages.

Growing from seed potatoes

Seed potatoes are potatoes that have been inspected and certified to prevent diseases from being passed along. Theoretically, you could use potatoes from the grocery store as seed potatoes, but many have been sprayed with growth inhibitor and others may bring diseases, such as fusarium rot, into your garden. Better to buy seed potatoes for planting. Second best is to plant from potatoes you saved last year.

If you want, you can chit potatoes before planting them out. Put the uncut seed potatoes in bright light for two to four weeks—a window sill is perfect. You will see green shoots coming out of the eyes.

If you want, cut the seed potatoes into equal-sized pieces, each with about two eyes on it. Some people prefer three eyes, some prefer one. If the seed potatoes are small, less than the size of a small chicken egg, you don’t need to cut them at all. The difference will be this: more eyes on a seed will yield more but smaller potatoes. Two sprouts is a good compromise.

You can shake the cut potatoes in a bag of sulfur powder if you like; it helps to prevent disease. Leave the cut potatoes out to callous over before planting for two to four days.

Trench and hill method

Dig a trench about six inches deep in a moist but not wet garden. Sprinkle about a quarter cup of bone meal where each potato plant will go: about every foot for full-size potatoes or every eight inches if you plan to harvest only new potatoes. Lay your seed potatoes in the trench. Cover them over with about four inches of dirt. Do not water them until you see growth. Water regularly from this point until the potatoes are fully grown. How much water? About one to two inches per week.

When the plants are a foot high, pile on another six inches of soil. You will cover the stems and a few leaves but that is okay. You should have a small hill around each potato plant.

When the flowers appear, you can harvest some new potatoes from the edges of the hill and leave the rest to grow, or you can harvest them all from the plant at this point, but they won’t store well. The soil should be loose enough to go digging with your hand,but if not, used a fork very carefully to loosen it.

Look for sprouts growing out of the eyes. These will grow into potato plants. This vegetable will readily adapt to container gardening.

The potatoes will be fully mature when the leaves die back a bit. Cut off the plants. The leaves of longerseason varieties won’t die back in cooler areas, so when the potatoes reach the size you’re looking for, cut off the plant. Leave the potatoes in the ground for two weeks after the plants are gone to let the skins harden up a bit, which is good for storing the potatoes. Do not water at all during these two weeks. Then dig them all up.

Brush off the dirt and leave potatoes in a shady area for a few hours. Do not wash them. Store them in a dark, cool area.

A variation to this is to hill up the potatoes with straw instead of soil. It makes it easier to harvest them and they come out cleaner. Plus, the straw can go in the compost or directly onto the garden after the potatoes are harvested.

Scatter method

Instead of digging trenches, place the seed potatoes on top of a bed of well-nourished soil. Alternatively, you can spread out 6 to 10 layers of newspapers on the ground and place seed potatoes on that. Then you put about four inches of mulch on top. Continue to hill up with mulch as the potatoes grow. Or you can mow a previously unused area and put the seed potatoes down, then top it with about 12 inches of straw or other mulch. No need to hill up; just let ‘em grow and harvest in late summer.

To hill or not to hill

The rationale for hilling potatoes is to prevent the tubers from seeing sunlight. Tubers grow very close to the surface and will push above the soil as they get bigger. Above the soil they will turn green, which renders them bad to eat. One solution is to pile soil around the potato plant after a few weeks of growing.

There is also an idea that potatoes will continue to put out roots from the stem as it is buried. Tomatoes do, and they’re the same genus. We haven’t found any scientific studies of this theory, but we have found some independent observation that potatoes only grow at the bottom of the plant; no roots grow out of the stem as it’s buried and no tubers.

Container method

If you’d like to practice extreme hilling in hopes of getting more potatoes, use a container. There are many potato-growing containers on the market, including bags, boxes and large pots. Some people use garbage cans or old tires. Just make sure whatever you use has drainage in the bottom.

Start with about six inches of potting soil in the bottom. You can amend the soil with up to one-third rotted manure. Place the seed potato pieces on the soil; these won’t likely be planted one foot apart but aim for roughly three plants in a garbage can. Don’t overplant because you may not get any potatoes at all, and any you do get will be very small. Add four inches of soil on top of the seed potatoes and water well.

Add more soil as the plants grow: when they’re up about eight inches, add four inches of soil, until you get to the top of the container. Make sure you keep containers watered well; they get dry faster than the ground.

The soil should be relatively loose when growing in containers, so you can harvest new potatoes by simply digging into the dirt with your hand. When it’s time to harvest the entire crop, it’s probably easiest to tip the whole container over and dump it out. Some of the potato-specific containers have drawers in the bottom you can open to get at potatoes. If that works for you, go ahead.

Let us know if you get more growing potatoes this way than by just hilling once.

Potato blooms come in purple or white.

What can go wrong

Late blight Phytopthera infestans, the disease that wiped out acres of crops and about a million Irish people is still around. The plant may look alright above ground, but the potatoes get black, rotting areas underthe skin. If the plant is showing ill health above the ground, look forwatery grey, black or brown spots on leaf margins and stems. Somestrains of P. infestans infect the tuber without showing on the leaves.There is no surefire way to prevent infection of your crop, but it willhelp to rotate crops and grow resistant varieties of potatoes.

Wireworm larvae of Agriotes or click beetle live in the soil for two to six years, overwintering there and eating live vegetable matter, including potatoes. These will be apparent when you dig up potatoes and find the worms in them. At this point, complete your harvest and rotate the crop for the following year. Wireworm won’t eat lettuce and onions. Till over the ground and kill any worms you see, or, if you have chickens, let them roam the area and eat the wireworms. Beneficial nematodes might work; it depends on what species of wireworm you have—and you may have more than one.

Colorado potato beetle Leptinotarsa decemlineata (CPB) eats leaves of potato plants in both its larval and adult forms. Inspect your plants regularly for adults and eggs, laid on the underside of leaves as small yellow ovals; unfortunately, ladybug eggs are similar, and ladybugs eat CPB. The best control is picking the bugs as you find them. A potato plant can lose up to 30 per cent of its leaves before harvest is reduced, so unless you have a big infestation, you’re okay. Chances are by next year beneficial insects will find your garden and have a feast before the Colorado potato beetle gets much work done.

Recommended varieties

‘Alta Blush’. Developed in Wetaskawin, Alberta, this variety is yellow, early season, and tastes great. Good for boiling and roasting.

‘Bellanita’. Yellow fingerling, small size, early season. High yield. Great for salads.

‘Chieftain’. Red skin, white flesh, mid to late season. Good for boiling, baking and fries. Resistant to scab.

‘French Fingerling’. Red skinned fingerling with yellow flesh. Late season, waxy, good for boiling and salads.

‘Gold Rush’. Early maturing alternative to ‘Russet Burbank’. Good for boiling or baking. Matures mid season.

‘Linzer Delikatess’. Yellow fingerling, waxy potato. Early season. Good for boiling and salads.

‘Milva’. Yellow flesh variety with

great disease resistance. Good for organic growers. Resistant to late blight. Waxy texture makes them good for salads, boiling or roasting.

‘Norland’. Red skin, white flesh, early to mid season, good for boiling or baking. Medium large size, slightly oblong. Good disease resistance. Good for storing.

‘Russet Burbank’. One of the best since 1874. Heavily netted skin, suitable for baking and fries. Late season. Oblong. Good for storage.

‘Purple Chieftain’. Purple skin and white flesh. Dry potato, good for boiling and mashing. Mid to late season.

‘Viking’. Red skin, white flesh, mid season. Good resistance to drought and scab. ‘

Yukon Gem’. Yellow flesh, mid season, good for salads. High yield, great resistance to scab and less susceptibility to late blight.

‘Yukon Gold’. Yellow flesh, mid season, good all-purpose potato. High yield. Gets big and stores well. V

Nutrition

Are potatoes good for you or bad for you? You can paint it either way.

On one hand, they contain vitamin B6, fibre, vitamin C, potassium and zero fat, which is good. On the other hand, they have a high glycemic index, which is not good. On the third hand, the vitamin B6 in them is good for heart health, and scientists have discovered kukoamines in potatoes, which lowers blood pressure. On the fourth hand, they don’t contain that much fibre and it turns out some fat is good for you.

It’s best to say that potatoes are fine in moderation. And probably not deep fried. Well… not very often deep fried!

A brief history of potatoes

Originating in Peru and under cultivation at least as long ago as 2500 BCE, perhaps as long ago as 8000 BCE, the potato provided the calories needed to build the Altiplano Incan civilization. They ate potatoes baked, mashed, boiled and stewed, in addition to turning them into chuño, a kind of dehydrated potato that is light and keeps for years.

When the Spanish decimated South America, they brought back to Europe silver, maize and potatoes. In the late 1500s, the first mentions of potatoes started to occur in Europe and spread quickly from the Canary Islands through to northern Italy and northern Europe. Carolus Clusius, a French botanist, wrote in 1601 that northern Italians used potatoes to feed animals and humans.

It took some time for potatoes to be accepted as food in Europe. All parts of the plant except the tubers contain solanine, a toxic compound, though that isn’t considered the reason for the slow acceptance of potatoes for eating. It was fed to members of the Spanish army and along the way was adopted by peasants across Europe, where Spain had interests. It was only in small-scale personal cultivation, though, until governments and landowners started to promote it as a crop. Growing underground, potatoes didn’t fail as often due to weather as wheat and barley crops.

In Ireland, where peasants had to rent a bit of land from a wealthy owner, they found that an acre of potatoes could feed a family for a year. By 1835, potatoes were grown on a third of farmed land in Ireland. They provided the only solid food eaten by 40 per cent of Irish peasants. It might not be an interesting diet, but potatoes kept people fed, effectively doubling the available calories across northern Europe. Famines, which occurred at a rate of just over once per decade before the tuber, seemed to be a thing of the past.

Seemed to be.

Phytopthora infestans means “vexing plant destroyer”. It is the technical name for potato blight. It seems to have originated in Peru and was brought across the Atlantic in a shipment of guano, used as a fertilizer. In the early summer of 1845, the first plants in Flanders were dying from infection. Potato plants in Europe were from a limited gene pool, planted by seed potatoes, which produce clones of the parent. By fall that year, blight had reached France, England, Denmark and Ireland. In Ireland, the disease killed off at least a quarter of the crops, and more the following year. The blight didn’t die down until 1852. A million people in Ireland had died and two million had emigrated.

In 1859, the Colorado potato beetle found its way into potato crops in the US. The insect isn’t from Colorado and it didn’t originally feed on potato plants. It’s from Mexico and originally ate buffalo bur, Solanum rostrum, a relative of potato. It seems to have made its way north on horses and cows moved by the Spanish and indigenous Americans. When the beetle found the potato growing in fields, it increased dramatically. Starting in Colorado in 1859, it made it to the Atlantic coast by 1874, and by that time it was blanketing beaches and completely covering railroad tracks, making them impassable. And of course, it killed potatoes too, eating the leaves before the tubers could mature.

The beetle leapt from North America to Europe in the twentieth century. There was an embargo on American potatoes but the beetle made it anyhow. It has been eradicated from the British Isles 163 times. Non-island parts of Europe and Asia haven’t been so lucky and it has become established around the northern hemisphere. The insect is susceptible to various insecticides, but it also quickly develops a resistance to them.

Despite these two major problems occurring with potatoes, they continue to be grown worldwide. They’ve been adopted by Chinese and Indian cooking and farming— in fact, China is the biggest producer of potatoes and India is in the top five, along with the US, Russia and the Ukraine. Potatoes have even slipped the confines of Earth; in 1995, potatoes were the first vegetable to be grown in outer space.

Phytophthora infaestans: A potato badly infected with late blight. It was responsible for the Irish potato famine in 1845-49.

Although originally from Mexico, the Colorado potato beetle has come to love potatoes as much as humans have.