Potatoes

Potatoes

Potato flowerz

I used to grow a big bed of potatoes each year, but since we do not eat potatoes as often because of the carb factor, I now only grow a hill or two to harvest new potatoes.  But I remember my grandfather looking at an empty lot, maybe 100 feet by 200 feet across the street from his house and telling me that during the war he grew enough potatoes on that lot to feed the neighborhood all winter.  That’s probably an exaggeration- and I don’t know how many neighbors he had back then- but potatoes are a good crop to grow if you need to provide a lot of your own food.

Potatoes are as easy to grow in the garden as their cousins, the tomatoes and peppers, but not as many people grow them.  That’s a shame, because home gardeners can taste some of the wonderful varieties of potatoes that are not found in the supermarket.  Even if you can’t grow your entire year’s supply of potatoes in the garden, you can grow enough to have some delicious baby new potatoes with several meals.  Potatoes can even be grown in containers.

Some varieties

There are hundreds of varieties of potato; each has its own unique flavor.  Most people are familiar with brown skinned or red skinned potatoes with white flesh, but there are many skin and flesh colors of potatoes as well as sizes and shapes.  Some varieties to try are - Russian Banana, French Fingerling, (small, finger sized tubers, unique nutty taste), Yukon Gold,  German Butterball, (yellow skin and flesh, buttery taste), Red Gold, Desiree, (red skin, yellow flesh), Kerr’s Pink, Adirondack Red (red skin, pink flesh), Red Pontiac, Red Norland, (red skin, white flesh) Adirondack Blue, Michigan Purple, (blue, purple skin, blue flesh).  Potatoes with brown skin and white flesh include, Green Mountain, Anoka, Superior, Kennebec and Butte.

Growing Potatoes

Potatoes grow well in most areas of zones 3- 8.  They will grow fairly well in any soil, but prefer sandy soil with a pH of 6.5 or lower.  If your soil is alkaline, (pH above 7), you can still grow potatoes, although they may be more susceptible to disease.  Potatoes require lots of water so may not be a good choice where it’s dry.  They will not grow well where the soil doesn’t drain well either.  Potatoes need full sun.

Potatoes are started from seed potatoes or “sets“.  Small seed potatoes are planted whole, while larger ones are cut into pieces.  Each piece needs one or more “eyes” or sprouts.  The pieces should be allowed to sit for a few days for the cut surface to dry and harden.  You can buy several types of potatoes in garden stores, but for the unusual varieties you will have to order from a catalog.  It will take about 1 lb. of potato pieces to plant a 10 foot row.

The grocery store potato controversy

You can cut up sprouting potatoes from the grocery store, but it may be better to buy certified seed potatoes.  Many people worry about using potatoes from the grocery because of the possibility of those potatoes bringing late blight, a serious disease of potatoes and tomatoes.  Many experts warn against using grocery potatoes for that reason.  There is a slight possibility of getting late blight from grocery potatoes.  And you can always get late blight on your plants later in the season even if you use certified potato sets.

If you are just growing a few potatoes I don’t think starting a few from the grocery is too big a deal. Here’s my reasoning on that.  Most potatoes with late blight rot quickly in storage.  If you are finding sprouting potatoes in spring in bags from the grocery store they probably didn’t have late blight.  If there is no rotting areas on the tuber the chances are even less.  Wash the tubers well with mild dish soap before getting them ready to plant.  Now your chances are very, very slim of those tubers carrying late blight. 

I would be more careful about keeping potatoes from farmers markets or organically grown potatoes from groceries for starting new plants.  Commercial, conventional potato farms monitor the crop and use preventative sprays for late blight if needed on potatoes.  Small growers may be less likely to monitor for late blight and more likely to miss infections and sell infected tubers.  (You can buy certified, organic seed potatoes if you want them.)

In short: If your garden is in an area with commercial potato growing farms around I would certainly stick with certified seed potatoes.  You wouldn’t want to be responsible for their loss of income.  If you are growing a lot of potatoes to feed your family and intend to store them over winter buy certified disease free seed potatoes.  Remember that just buying certified seed potatoes will not prevent the disease from coming to your garden.  It can be transferred to your plants by other things, including coming in on the wind. But for just a few potato plants using well sprouted grocery store potatoes is relatively low risk.

There’s one other problem often mentioned when talking about grocery store potatoes being used for planting.  Some potatoes are treated with a chemical to prevent sprouting.  But if your grocery store potatoes already have large sprouts, that’s not a problem.  Once the plants are sprouting they will perform as well as seed potatoes after planting.  To see if the potatoes will sprout, if they don’t have sprouts, wash them and set them in a sunny window.  You should get good sized sprouts in 2-3 weeks.

The actual planting

Potatoes can be planted outside as soon as the ground is ready to be worked and is moderately warm.  You don’t want any hard freezes to come along, but they will withstand light frosts with no damage.  Potatoes are a crop that needs to be rotated, so don’t plant potatoes where they were planted last year.  They should not be planted where tomatoes, peppers or eggplant grew the year before, as they are all related.  Crop rotation helps prevent disease and nutrient depletion of soil.

To grow potatoes make a trench in the soil 3-4 inches deep. Place the seed pieces 8-12 inches apart and cover with soil. If the pieces have sprouts it’s fine to cover them so just the tips of the sprouts are exposed.  Rows should be about 3 feet apart.  When the potato plants are about 6 inches tall, mound up soil or mulch until just the top leaves are showing.  The mounding is done again when the plants are about 6 inches above the first mound.  An alternative to mounding with soil is to use straw, dry leaves or other mulch to cover the plants as they grow.  This allows you to harvest clean potatoes from down under that mulch very easily.  The disadvantage is mulch may be blown or washed away which leaves the tubers exposed to sunlight.  Mice like to hide in mulch to nibble on potatoes also.

You can also grow potatoes in containers.  A container the size of a half whiskey barrel can easily yield 5 pounds of potatoes.  Make sure the container has drainage and that you water it as soon as it feels dry.  Use light weight potting soil to half fill the container, press your seed pieces into the soil, and cover the plants stems with mulch as they grow.

Potato problems

Potatoes may suffer from Potato Beetles, Flea Beetles and other insects.  The easiest way to deal with those pests is to cover the plants with floating row covers.  This light material allows light, air and water to pass through and potatoes do not need to be pollinated to make tubers. 

Fungal disease (late blight), can sometimes be a problem with potatoes. Late blight can be spread from infected potatoes used for planting, or from infected tomato plants. It can also blow in on the wind.  Late blight causes rapid blackening and wilting of plants and the tubers will have dark areas and rot quickly.

Once plants get a fungal disease there is no cure. Crop rotation, and using certified seed potatoes, can help prevent disease.  Non-organic growers can use preventative fungal sprays, sold in garden stores.  Clean up the garden and make sure not to leave any potatoes in the ground.  If you had disease problems in your potatoes do not put them in the compost pile.  This can allow spores of disease like late blight to survive winter.  Bury them deeply, dispose of them in a landfill or burn them.

Scab on potatoes causes crusty darkened areas on potato skins. It’s a virus that needs certain environmental conditions to thrive.  Scab is mainly a cosmetic problem, and the scabby area can be peeled off and the potatoes are fine to eat.  Scab is often caused by soil that’s alkaline, (high pH) or other environmental conditions such as moisture stress at certain growing points.  It can also be caused by adding manure to the potato bed in the spring.  Rotating crops helps prevent scab.

Hollow centers or brown centers in potatoes, are also caused by environmental conditions, usually irregular watering, dry spells followed by lots of water.  Cold temperatures for long periods at planting can also produce the problem.  Some varieties are more susceptible to this than others.  The potatoes are safe to eat but don’t store as well and there is some waste when the hollow areas are removed.

Harvesting

Potato flowers are quite pretty and can be white or shades of purple.   Potato flowers do make seeds on occasion, which look like small hard green tomatoes. It’s not advisable to save these for planting.  Depending on weather and the variety, plants began blooming about 2 months after planting.

As soon as you see your potato plants blooming, dig down carefully and harvest some new potatoes.  If you cover the stems back up and don’t take all the little potatoes, the remaining ones will mature to full size. 

A few weeks after flowering the potato plants will begin to die. This scares some new gardeners, who think the plants are drying up and dying from disease.  This is just a signal that, once the plants are brown and dried, mature potatoes are ready.  You can dig them now or wait a while, but they must be dug before a hard freeze.  Any tubers that you damage should be used right away.  Let them dry in a warm, dark area for a few days, then brush the soil off and store in a dark place with temperatures between 40-60 degrees.  Don’t wash potatoes until just before you use them. 

Stems, leaves and all green parts of the potato plant are poisonous.  Green areas on tubers are also poisonous and should be trimmed off before cooking.