How to Grow Potatoes

Days to germination: n/a
Days to harvest: Starting around 60 days
Light requirements: Full sun
Water requirements: Consistent watering
Soil: Well-dug with added organic matter
Container: Possible

Introduction

Potatoes come in all shapes and sizes, from the standard large Yukon Gold to more exotic purple potatoes. Fingerling potatoes are small and skinny, like the Russian Banana variety. There is always something a little exciting about digging up your hill of potatoes and seeing what kind of harvest is hiding under the dirt.

These starchy tubers aren’t usually treated like a vegetable when it comes to cooking, but they are a basic staple in most homes. Potatoes are always cooked, but can be eaten boiled, fried or mashed. They are high in fiber, vitamins C and B6, and low in calories.

Starting From Seed

The planting process for potatoes is fairly unique. Home gardeners don’t plant seeds, but rather seed potatoes directly into the garden. Seed potatoes are just small potatoes that have been kept from the previous year’s harvest. You can save your own over the winter, in a cool dry place or you can just buy new seed potatoes each year when it is time to plant.

Seed potatoes are usually small, and should have a few “eyes” on them. You can get a jump start on the season by letting your seed potatoes begin to sprout before planting them. Just leave them out where they can get some light for 2 weeks before your planting date.

You can extend your seed potato supply by cutting larger ones in half, as long as both pieces still have eyes on it. If you do cut your potatoes, do so a few days before planting so the fresh cuts are not exposed to the wet soil.

Potatoes are very heavy-feeders so dig your garden area thoroughly with added compost or aged manure. Dig down to loose the soil to at least a foot in depth. They will need full sun and a warm part of the garden.

You can put your seed potatoes out about 1 to 2 weeks before you are due to get the last frost of the year. The tubers should be buried about 4 inches deep, but only 12 to 16 inches apart if planted out in rows.

Though the plants can be pretty close together, the roots underneath will spread several feet. Don’t plant any other vegetables near the potatoes by at least 3 to 4 feet.

Growing Instructions

Once the plants begin to grow, about 12 inches above the soil, you should “hill up” the earth to cover them by another 4 inches. You’ll likely be covering up some healthy green leaves, and that’s fine. Potato tubers grow right under the surface, and adding extra soil after the plant starts to grow ensures that they stay underground. Any tubers that poke through will be exposed to sunlight and start to turn green, which will make them unfit to eat. As the plants grow, you can pile more soil on to increase the hill size. The stem will produce more side runners, and increase your overall harvest.

Once the plants have sprouted, take care to water regularly. Until that point, water sparingly to help prevent the seed potatoes from rotting. If you use fertilizer with your potatoes, choose one with low levels of nitrogen (or none at all). Nitrogen encourages the plant to grow, but not to produce tubers.

Another option for growing potatoes is to cover the growing plants with hay instead of dirt when you make the hills. Make sure the layer of hay is thick enough to keep out the sunlight. Your plants will make their tubers in the hay, which can make for a much easier (and cleaner) harvest later on.

When your plants start to produce flowers, you should stop hilling. You don’t want the plants to send out any more shoots at this point, so it can use its resources to build tubers.

Containers

You can grow potatoes in containers though it’s not all that practical. The container should be very large, like a barrel or even a big garbage can. It will need holes in the bottom for drainage.

Start your seed potatoes several inches below the edge of the container, to allow for hilling as the plants grow. When its time to harvest, its easiest to dig up the entire plant. Trying to harvest just a few potatoes at a time is awkward given the confines of the container.

Pests and Diseases

Unfortunately, potatoes are vulnerable to many pests and diseases that can effect your potato crop.

Scab is very common, and thankfully not destructive. You will find crusty growths on your potatoes but they are still perfectly edible. They just won’t look so appealing. Adding too much lime to your soil can cause scabbing.

Another problem that is more damaging is blight (both early blight and late blight). The leaves will start to discolour and wilt. The tubers are also effected, though you can’t see them underground. Copper-based sprays can be used against blight, but may not be much use once the disease has taken hold. Never save blighted potatoes to seed the next year.

Not surprisingly the potato beetle is a big insect pest to home garden potato crops. These striped insects will eat all the leaves off your plants if given the chance. You can pick them off by hand as they are quite visible. Pyrethrin-based insecticide sprays can help keep them off your plants as well. If you have problems with beetles, rotate your potatoes to another part of the garden to keep eggs from re-emerging the next year.

One last possible threat are wireworms. They are beetle larvae that live in the soil, and eat your growing potatoes. Their eggs are usually laid in grass, so any garden plot that has recently been converted from lawn might have a problem. There is little you can do, except plant your potatoes elsewhere next season.

Harvest and Storage

You can usually start digging up small “new” potatoes around 7 to 8 weeks after you plant the seed potatoes. Your plants can keep making potatoes for several more weeks if you are careful when you start to harvest.

It may be easier to wait until the vines start to die down, then just dig up the entire plant. If you plan on storing your potatoes for later winter use, leave them in the ground for a week or two after the vines have died. Their skins will be tougher, and they will store better.

Once they have been dug, don’t let them lay out in the sun or you will get inedible greened potatoes.

Potatoes store best in temperatures a few degrees above freezing, but fairly humid. Cool, damp basements or garages can work very well. They can keep for several months this way. Check them every few weeks though, and remove any that begin to spoil before they spread rot to the whole batch.