Crops

How To Grow Potatoes

Planting potatoes, growing them into beautiful plants, and then harvesting two handfuls of small, knobby potatoes can get any farmer frustrated. However, if you plan and do things properly from the beginning, you can have a good harvest.

The humble potato is happy to call just about any place home, so long as a few basic rules are followed. You can grow them not only in the ground, but in pots, tyres, old compost bags, buckets, sacks… you name it.

When to plant

Zambia has three major potato growing seasons:

Plant summer, rainfed potatoes in November. To avoid seed damage due to high temperatures, plant after the rains have started.

Plant irrigated potato crops in February. Try to plant earlier in the month so you can harvest before winter when low temperatures damage the crop.

Growing Potatoes in Containers, Pots and Bags

The problem with growing potatoes in bags in that when the soil temperatures rise above 25°C, potato plants signal their roots to stop making tubers.  Instead, the plants may rev up other reproductive strategies, like developing more fertile flowers, or popping out little green potato-like organs on the main stem. Furthermore, the containers cause a dwarfing effect on potatoes potatoes in bags. The plants sense that they are growing very close to each other and end up producing numerous small tubers rather than a few large ones.

According to research by Master Gardeners where they compared the productivity of ‘Carola’ potatoes grown in beds, bins, bags and pots, these were the results:

Growing Method Average Yield Per Plant
Mulched raised bed in the ground  1 kg
Wire bin 0.32 kg
Plastic pot 0.28 kg
Potato bag 0.26 kg
Burlap bag 0.11 kg

Based on these results, you can decide which method is best for you. There are several types of potatoes, each with its unique characteristics. Whichever your choice, the growing method is almost the same.

Preparing for planting

Crop rotation is very important when it comes to growing potatoes so choose a place where you haven’t grown potatoes or tomatoes in a few years. The success of your crop depends a lot on the tubers you select. Potatoes are planted from last years tubers and not from seeds as many may think. Therefore, ensure that the potatoes you keep from the previous year for sprouting are fungus free. It is also advisable to buy certified seed potatoes from nurseries which are not only virus and disease free but also produce a good yield.

Before you plant your potatoes, place them in a warm, sunny spot. The warmth will encourage sprouting, and exposure to sunlight will make the skins turn green and bitter making them less appetizing to critters.

Then two days before planting, cut the sprouting green potatoes into pieces smaller than a golf ball whole that have at least three “eyes” on each piece. Allow the cut pieces to dry. The drying could make them turn black. The darkened, leathery surfaces will resist rotting better than freshly cut ones. Therefore, every piece you plant should grow.

Planting Potatoes

If you want grow potatoes that are bigger than your fist,  you will need to space the rows at least 36 cm apart. You can even go even wider and plant potatoes in raised beds, with 3 plants every 61 cm diameter raised beds.  Potato raised beds are flattened mounds about that are about 15 cm high. This is the best way to grow potatoes.

You can grow your potatoes in the same bed with cabbages, maize, horseradish, parsnip and peas. Potatoes don’t grow well with cucumbers, onions, pumpkins, sunflowers and tomatoes.

Caring for your plants

After planting potatoes, you can mulch them right away about 8 cm deep, or you can let the soil warm in the sun for a few weeks before you pile on the mulch. Any biodegradable mulch will do, but using a deep hay or straw mulch is an especially good way to grow potatoes. Mounding up or mulching around the plants is very important. It helps cover the roots and the young potatoes thereby, protecting them from the sun and at the same time reducing weeds. This can encourage a much heavier crop.

Most veggies just need about 5 cm deep mulch, but potatoes need more. So, every few weeks, check for gaps or thinned spots, and pile on mulch until it is 4 – 10 cm deep.

Watering Potato Plants

Keep your potato plants watered especially after they sprout so they can swell into full size potatoes but, don’t overwater. Too much water can make  your potatoes brown at the center or hollow or soggy. Try to water in the morning so that the leaves can dry in the sun to avoid any disease.  When the leaves of your potato plants start to turn yellow and die back, it’s time to stop watering for next two weeks. It is time to harvest your potatoes.

Fertilizing your potatoes

Potatoes generally do not need fertilizers especially if the soil is enriched with compost. You can mix some blood and bone in the soil or a general purpose granular vegetable fertilizer to improve the quality of the soil. You can also spray 5-10-15 liquid fertilizer on the leaves before the plants bloom. Try as much as possible to avoid fertilizers rich in nitrogen because nitrogen produces leafy growth and less tubers. Also, too much fertilizer can reduce the flavour of your potatoes. Mulch is better for potatoes than fertilizer.

Harvesting Potatoes

Potatoes need anything from 60 to 90 days in warm soil to grow well for a successful good yield. Generally, harvest is three or four months after planting depending on the conditions, variety and your circumstances. Once the plants on top start dying, you can harvest your potatoes.  Each potato seed you plant can produce 10 potatoes at harvest. Therefore 1 kilogram seed potatoes and could harvest about 20 kg.

Happy planting!

22 thoughts on “How To Grow Potatoes

    1. Hi Bevin,

      It’s impossible to give a definitive program until you’ve tested your soil to find out how rich or poor it is. Most commercial chemical feeds specific for potatoes are balanced as 2:2:3, that is equal amounts of nitrogen and phosphorus with half as much again of potash or 3:5:5. The nitrogen and phosphorus will feed the haulm (foliage) and root system with the potash feeding the tubers themselves. Managing nitrogen is crucial to success with potatoes. Too much and you get a lot of top growth at the expense of tubers. However, it’s all in the timing. You have to calculate how much nitrogen your plants need. Each plant only needs a total of 6g total nitrogen for the whole season. Go with granular nitrogen to make it easy to measure.

    1. Hi Hamaimbo, With changing weather patterns, it’s not easy to give a specific period. However, they should be grown between January and March.

    1. First of all, you need to know the nutrient level in the soil.Without soil analysis then you will have to rely on your judgement as to the fertility of the soil. Even a good guess isn’t as good as knowing though. Also, if you’ve just applied manure, then you might well end up with too much nitrogen.
      Assuming, the above is followed, applying basic NPK fertiliser will ensure you provide the micro-nutrients (the plant equivalent of vitamins) required for a high yield of healthy potatoes.

    1. After approximately three weeks from planting, when sprouts begin to push up through the ground, you have to with mound loose dirt, leaves, straw or compost, around the sprouts. If you do use maize stocks, ensure they are not diseased.

  1. I have found this interesting and therefore since we are in January I intend to plant potatoes. But I need to be clear on seeds to use. Should I go for certified seed if there is any or just buy small potatoes and plant them? Which one is better?

    1. Hi Locho, Please read this article:

      If you buy small potatoes and plant them, you’ll grow and reap small potatoes.

  2. Very educative can D compound fertilizer be used if so at what stage.
    What can one use when it comes to spraying pests

    1. The potato can be grown almost on any type of soil, except saline and alkaline soils. Loose soils such as loamy and sandy loam soils that are rich in organic matter, with good drainage and aeration, are the most suitable.

  3. if i want to plant potatoes in rain season,which month is recommendable and what does potatoes require e.g like fertilizer,spraying chemicals?

    1. You can grow potatoes all year round if all conditions required are met. If you plant now, you should be harvesting by year end, then you can plant again then and harvest before cold season. Please use the search function our site and search for “potato”. We have a few articles on the subject.

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