Nothing is more satisfying to grow than potatoes, especially the early varieties that are planted in October and early November and which, with any luck, mature in time to be included on the Christmas dinner menu. But as more of us downsize and move into apartment-style living or retirement villages, garden space is at a premium and potatoes often have to play second fiddle to ornamentals, or disappear off the growing programme altogether. This is where containers come into their own. They can be filled with mix and placed on a hard surface such as the edge of a path or deck, then emptied once the crop is harvested, and conveniently stored away until the next season. However, growing potatoes in containers requires a special set of skills if it’s to be successful.
While a standard 10-litre plastic bucket will suffice, it should be considered as a minimum size, and anything deeper will be even better. While it has been common practice in the past to grow potatoes in car tyres, this is now not recommended due to the leaching of undesirable chemicals from the rubber compound.
Drill several holes in the base of your container but don’t be tempted to place stones or other materials in the bottom to assist with drainage. They are not necessary to allow water to pass through, and will only take up valuable growing space.
The growing medium
Avoid regular garden soil as it is too heavy and readily compacts. Instead, choose a loose medium-fine compost to which has been added well-rotted animal manure, a handful of blood and bone, and a couple of tablespoons of superphosphate, well mixed through. Alternatively, mix in a commercial potato fertiliser.
If you want to produce one or two really large potatoes, cut a cone-shaped segment from a seed potato, taking with it a single well-developed shoot. Plant it halfway down in a small container filled with soil. Once the new growth has come through the soil and has at least four sets of leaves, transplant it into a bucket so that it is level with the top rim.
If you want to grow a reasonable quantity of small to medium-sized potatoes, plant a seed potato that has a good number of shoots coming from it. Fill the bucket one third with the growing mix. Place the potato on top, and lightly cover. As the stem grows taller, add more growing mix to the bucket so that the leaves are just visible poking through. This will encourage potatoes to develop along the full length of the stem.
Head in the sun, feet in the shade
Potatoes grow best in soil temperatures that are between 15 and 20 degrees Celsius, and where their leaves receive plenty of sunlight. In a confined space, soil heats up quickly so keep the temperature down with regular watering and by shading the container (but not the foliage). If you do have a spare space in the garden, even if only temporarily, dig the container into the soil to help keep the contents cool.