Most of us have relatives and ancestors that came to the US to escape government, poverty, famine or just for a chance at a new life. My ancestors left Ireland due to the potato famine in the late 1800s. They settled in upstate New York, where it turns out, potatoes did not really prosper. They eventually switched to dairy faming and have been very successful at that since. However, if they had heard how great Wisconsin conditions are for potato production, my history here might have started a lot sooner.
The story of the potato starts out between 10,000 and 7,000 years ago in the Andean Mountains, near modern day Peru and Bolivia. Potatoes were a key crop for Incan farmers in the 13-16th centuries. Here it was introduced to Spanish explorers and brought to Europe around 1570. They were not hugely popular but often used by sailors to prevent scurvy due to the high vitamin C content. Ireland became the country to really depend on the crop by the mid 1800s. Late blight caused three consecutive crop failures between 1845 – 1848 and lead to the death or emigration of more than 1.5 million Irish. Many immigrants brought the potato with them to the US but it had already been around since colonial times.
Today, the US is the 4th major producer of potatoes in the world. Wisconsin is the #3 producing state in the US, behind Idaho and Washington. Most of these potatoes go for frozen fries or fresh use.
Potatoes are an awesome food source. One medium sized potato has only 110 calories, no cholesterol and is fat free. It will provide you with 45% of your daily value of vitamin C, plenty of fiber and protein. One potato has more potassium than a banana and is a good source of vitamin B6 and antioxidants. Much of this goodness is in the skin, so don’t forget to enjoy that part!
Potatoes grow well in Wisconsin due to the native soils and their natural adaptation to a cool climate. Optimal temperatures range from 55 to 80 degrees as long as it’s not too hot at night. And they are tolerant to light frost, making them great for northern gardens.
It is best to plant potatoes when the soil temperature reaches at least 45 degrees, with 55 being optimal. Many people traditionally plant around Good Friday but because this holiday can vary, April 15th is a general rule of thumb. You can keep planting rounds up until July.
It’s always best to start with certified disease (virus) free seed potatoes. These can usually be purchased at garden centers, co-ops, grocery stores and online. Eating potatoes from the store have not been certified and sometimes have even been treated with a sprout inhibitor.
Cut the seed potatoes into pieces that are golf ball to chicken egg sized. Make sure each of these chunks has at least 1-2 eyes. Many people prefer to do this a day or two before planting in order to let the cuts dry a bit at room temperature and start to callus. This helps protect the piece from being attacked by soil microbes that could rot it before it has a chance to grow. However, if your soil is warm and good quality, this curing process is not absolutely necessary. Every gardener has a preferred method.
Potatoes prefer a rich, loose soil. Old cow manure or compost are great additions to till into your potato bed, as well as the rest of your garden. There are many schools of actually planting potatoes. The basic method is to make a trench 2-8” deep, place potato pieces 10-15” apart and cover with 2-4” of soil. Some people continue to mound the soil into the trench gradually as the vines grow, stopping once the vines are 4-10” tall. Others create this hill right at planting. Hilling helps to keep sunlight from reaching the developing tubers which leads to green spots on the skin. This is actually a toxic alkaloid called solanine.
Potatoes require about an inch of water a week. However, they are tolerant of less than that and mother nature usually provides enough for them to produce. If you have sandy soil or it’s a particularly dry season, some irrigation might be required.
Harvesting can start as early as ten weeks after planting. This would be for ‘new’ or ‘baby’ potato types. It’s possible to gently root around in the hill to find enough for a meal, leaving the plant to continue producing. The appearance of blossoms is usually a good indicator that some potatoes are ready. The rest of the crop can be harvesting when the tops die back. Try to dig most of them up before the first frost, cure in a dark, dry place at 50-70 degrees for a week or so, then store at 35-40 degrees with fairly high humidity. Good air circulation will help keep soft spots, mold and sprouting from occurring.
Many gardeners have also been using alternative and creative methods for growing potatoes. Straw bales, potato bags, 5 gallon buckets and even stacks of tires are all new ways to have a potato harvest. Many of these methods are great for small areas.
Pests and Problems
Potatoes do not have too many problems in Wisconsin, especially if using certified seed. Growth cracks, scab, and blight can be issues for some gardeners.
Growth cracks are simply caused by very rapid growth. This is especially common when a dry period is followed by heavy rain or irregular irrigation.
Potato scab is a bacterium that creates brown, corky lesions on the skin. The spots can be a bit sunken and in severe cases, lead to pitting. The bacterium naturally occurs in many soils. Tubers are still edible, just peel first. Plant resistant varieties if you’ve had a history with scab.
Blight is starting to be more of an issue in Wisconsin. This fungal disease led to the famine in Ireland and can be devastating to a crop. Symptoms start as leaf spots which can lead to total defoliation of the plant and even death. Cleaning up old material, crop rotation, planting resistant varieties and having good airflow are the best methods for prevention.
The main pest of potatoes is the Colorado potato beetle. Control of the adult beetle is as simple as crushing them by hand before they lay their eggs. Eggs can be found on the undersides of leaves in clusters of bright orange-yellow. These can also be disposed of by hand. There are pesticides available to treat the larvae stage but they often need to be reapplied. Some years you might hardly see one and some years, you’ll throw your hands up and let them be.
Leafhoppers, aphids, and nematodes are also commonly seen but not too devastating for most home gardeners.
Potatoes are one of the easiest and reliable crops to plant. There are many varieties to choose from. Have fun trying different ones and stocking your pantry with bakers, mashers and baby reds.
Red Norland – early season, round to oval, smooth red skin, moist flesh is white and highest cooking quality, potato salad, frying, good scab resistance, stores well
Red Lasoda – midseason, high tolerance of heat, beautiful smooth red skin with pure white flesh, baking, never loses its flavor, best storing red potato, scab susceptible
Mega Chip – medium to late season, light tan skin and white flesh, great storage, great for baking and chipping, good scab and light blight resistance, replaced Kennebec
Kennebec – large, think-skinned, oval white flesh, dry and flavorful, cooks and bakes well, one of best for winter storage, good blight resistance, late midseason variery
Russet Norkotah – early season, high yielding, delicious, baking, boiling, good scab resistance, ideal baked potato, fried, mashed
Russet Burbank – late maturity, long tubers with tan skin and white flesh, excellent cooking and processing qualities, good scab resistance
Yukon Gold – midseason maturity, round to voal golden skinned with creamy yellow flesh, great buttery flavor
Blue/Purple – small to medium sized tubers, blue or purple skin and flesh, mild flavor, good for roasting, grilling, salads, baking
Fingerling – 2-4” long tubers with waxy, firm texture, buttery, nutty flavor, great pan-fried, roasted and in salads