How to Grow Potatoes in Containers

The skill of how to grow potatoes in containers is a surprisingly simple one to learn! Great news for people restricted by the amount of growing space they have.

The science of how to grow potatoes in containers is a surprisingly simple one, and thanks to this method, potatoes can be grown in very restricted spaces using containers, bags, pots, sandbags, or specially designed potato planters & barrels. This is great news for people like me, who are restricted by the amount of growing space they have available to them. I have a tiny patio on which I am trying to grow as much food as possible, and thanks to this simple method, it means I can enjoy growing potatoes too!

It’s easy to get good results with just a little understanding of how the basic arrangement works.

Potato Basics
Potatoes are grown from ‘seed potatoes’ or ‘tubers’ which are grown specifically for replanting and are not intended for human consumption (edible potatoes are known as tablestock). Seed potatoes are grown under strict conditions so that they can be certified as disease-free. However, after saying that, if you have a bunch of regular potatoes sat in the bottom of the cupboard that have started to sprout, you should be able to plant those too, although they may not grow as successfully or as aggressively as dedicated seed potatoes.

There are many varieties of potato that all fall within the following categories:

  • First early
  • Second early
  • Early maincrop
  • Maincrop
  • Late main crop.

The categories are fairly self-explanatory;

The first earlies are planted early in the year, and provide the first crop. Some first earlies can be planted as early as February and produce a crop within about 100 days in May. Second earlies will take three to four months to mature and are planted a few weeks after the first earlies, giving you another crop in June-July. The early maincrop potatoes are planted a few weeks after the second earlies and will take four to five months to mature, and so on, eventually bringing us to the late maincrop varieties which can be harvested as late-on in the year as November, or even Christmas with some new varieties being introduced. So get your timings right, and you can have potatoes almost all year round.

Crop Rotation
It’s also important to understand that potatoes favour crop rotation and will not grow well in the same soil for at least three years. However, other plants will do well in the same soil after potatoes have grown there, such as brassicas and root vegetables. Obviously if you are growing in bags or pots, you can change the soil each year, but be sure to clean the pots thoroughly with something like a 3% Hydrogen Peroxide solution.

Chitting
Chitting is another important element when learning how to grow potatoes, and is where you encourage your seed potatoes to start sprouting and growing shoots. Chitting is not essential, and the un-sprouted tubers can be planted as they are, but chitting will aid greatly in getting an earlier crop.

To chit them, simply leave your seed potatoes in a cool dark place. There does seem to be some confusion as to whether they should be left in the light or in the dark, so I put it to the test.

With my first early seed potatoes this year, I put some of them on the windowsill in the light, and some of them in the dark cupboard under the stairs. The ones under the stairs sprouted nicely, but the ones in the light did not sprout (I’ve now moved them all under the stairs.) So hopefully that simple test has cleared up any doubts or confusion.

The key here is to allow a small number of eyes to sprout on each potato, not more than about two or three. Any more than that and the crop will become weak, yielding only small potatoes, so once you have three good sprouts, remove the rest by rubbing them off with your thumb. This will give a slightly smaller yield but the potatoes will be much larger.

You can also cut the seed potatoes into two, or even three separate plants. Just ensure that there is at least one, but preferably several eyes on each segment. It is also suggested that the smaller you divide the seed potato, the smaller your resulting potatoes will be, so do not cut them up too much. Some gardeners say no more than halves, others will not cut them at all.Once cut, the potatoes will need to heal and callous over by allowing them to dry for a few days.

 

How to Grow Potatoes in Containers
As I said earlier, learning how to grow potatoes is a very simple and straight forward process. All you need is a nice sunny spot, and a container. You can use any kind of container from a dark polythene bag to a dustbin, and pretty much anything sized between. Some gardeners use discarded compost bags as they are an ideal size.

You could also make a large circular loop of chicken-wire and line the inside of it with cardboard, then add soil as per the instructions below. At the end of the growing season, just cut away the chicken-wire and you’ll be left with a big pile of earth full of potatoes!

Regardless of what container you choose, the most important thing is to ensure it has plenty of drainage i.e. lots of holes cut or drilled into the bottom to allow water to run out. Also, if the container is translucent or will let in light, you will need to cover it with something such as cardboard or newspaper to prevent the light hitting the growing spuds.

Once you’ve chosen your container, follow these simple steps:

  1. Fill your container / bag with four to six inches of good quality compost.
  2. Place your tubers onto the top of the compost, so the sprouts (if chitted), or eyes are pointing upwards. Space them sparingly – for a twelve inch diameter container, only use a maximum of three tubers. For a fourteen inch diameter container use about four tubers, and so on.
  3. Cover the tubers with another four to five inches of compost, and water sparingly. From here on, keep the soil continuously moist but never wet.
  4. If you are using a flexible bag as a container, it would be a good idea to roll down the sides, to help the sunlight reach the plant foliage as they grow.
  5. As the plants appear and grow taller, continue “earthing up” by adding more soil so that only the top inch or so of the plant is peeking through the soil. The new potatoes will form in an upwards and outward direction from the original planted seed potato, so continue “earthing up” until you reach about 1.5ft(18in) to 2ft(24in) of soil depth.

Feeding & Watering
Watering is where it can all go wrong when learning how to grow potatoes, so pay close attention to the moisture levels. Growing potatoes need to be continuously moist, never wet, and must not be allowed to dry out! The guy spinning the plates on the sticks springs to mind here! So if you haven’t installed a reliable irrigation system, you’ll need to be disciplined and keep a close eye on the soil regularly. You will probably have to water at least twice a day during the summer time.

Feeding with a liquid organic fertilizer or even tomato feed once every fortnight will ensure you achieve a good crop with maximum yields.

Harvesting
The potatoes will be ready for harvesting when the plants start to turn yellow, but they will start providing an edible a crop before then. Get your hands into the soil and have a rummage around. If any potatoes feel ready to be harvested, then by-all-means pick them. Green potatoes are poisonous – avoid. An important thing to remember when learning how to grow potatoes, is that the potato plant is a member of the nightshade family!

Harvesting
The potatoes will be ready for harvesting when the plants start to turn yellow, but they will start providing an edible a crop before then. Get your hands into the soil and have a rummage around. If any potatoes feel ready to be harvested, then by-all-means pick them. Green potatoes are poisonous – avoid. An important thing to remember when learning how to grow potatoes, is that the potato plant is a member of the nightshade family!

Freshly harvested potatoes are fabulous if eaten straight away! If you intend to store them, allow then to dry a little in the sun for an hour or two, then place in paper or cloth bags and store in a cool dark place.

Diseases and pests
Potatoes have historically been susceptible to certain types of disease such as blight. Blight is also a disease that can spread and ruin your tomato and other crops, and it is for this reason that you need to grow your potato plants away from your tomatoes, as well as your cucumbers, squashes or any other types of vegetables in the marrow family.

A good companion for your potato plants would be beans, marigolds and cabbages.

There are varieties out there on the market nowadays that are much more resistant to these issues. Another way to help protect your crop is to feed it with organic composts rather than with artificial fertilisers which can attract more pests.Also, growing potatoes in containers will help to minimise the risks, especially if you are using new compost / soil each time.

Buying fresh tubers each year from reputable dealers will usually ensure a trouble-free disease-free growing season.

Saving Seeds
Saving seeds from your crop should be ok for the first few years, but you may find a deterioration over the subsequent generations due to the build up of inherent virals and diseases.

Seed potatoes are grown in certified disease-free areas, often at high altitude to ensure the crop remains disease free. This is necessary because of the generational deterioration issues.