How to Successfully Grow Potatoes in Containers

2 March 2012, written by Benedict Vanheems

What could be better than unearthing handsome nuggets of potato from a chocolate-brown soil? It’s the epitome of the grow-your-own experience, an irresistible representation of everything that’s wholesome about growing good food at home. Personally I wouldn’t be without my annual crop of spuds. Straightforward to grow and yielding buckets full of tubers, the potato crop is easily my most eagerly anticipated moment of the kitchen gardening year.

Needless to say not everyone has the space to devote to this often rambunctious vegetable. With rows requiring a leg-stretching 45cm (18in) between them, a few bags of seed potatoes hanging invitingly on the garden centre shelves can soon turn into a space-planning headache. Surely just one more bag of spuds can be fitted in somewhere? Don’t count on it!

Pots o' Spuds

The solution for many space-starved gardeners is to grow their potatoes in containers, and not just pots but sacks, stacked tyres, old compost bags, the kitchen sink – you name it. Given its vigour the humble potato is happy to call just about anywhere home, so long as a few basic rules are followed. An eruption of lush foliage, courtesy of a few carefully positioned pots, can even become a feature, particularly on the patio where they would make the perfect foil for showier specimens.

Of course, growing out of the ground like this isn’t just for the chichi inclined. There are sound practical benefits to trapping your tubers within the confines of a container, including freedom from soil-borne pests and diseases such as eelworm and scab (an all-too-common setback for many), the chance to give the back a rest from digging, and the opportunity to try lots of different varieties of potatoes without (a) getting them mixed up and (b) worrying about things like crop rotation. Container spuds are also great fun for the kids. Have I convinced you yet? I hope so!

Some 'Ground' Rules for Container Potatoes

Don’t worry, there aren’t many of these. The most important rule is to match the number of seed potatoes to the size of container you are growing them in. As a rough guide each potato plant needs about 10 litres, that’s just over 2.5 US gallons, to grow into. Cramming your potatoes in is a false economy, the result being very small spuds, if you’re lucky enough to get any at all. A typical dustbin/garbage can-sized container would hold around four plants. Potato growing sacks sold specifically for this purpose, would house three. It really doesn’t matter what container you use, so long as it has adequate drainage holes at the base to allow excess water to freely drain away.

Spacing is important when planting potatoes in containers

Almost as important is what type of potato you grow in your container. First and second early varieties work best and have the added advantage of being done and dusted before the ever-present threat of potato blight arrives on the scene later on in summer. Salad potatoes work especially well and I love the variety ‘Charlotte’ for its firm-yet-creamy, oval tubers. Others worth seeking out are flavoursome ‘Lady Christl’, the appropriately named ‘Rocket’ and quirky, nutty-flavoured ‘Anya’.

The final rule is to keep your potatoes well watered. While ground-grown plants have the luxury of reaching down to chase valuable soil moisture, their container cousins have no such luxury. Be on hand to water plants as they grow and particularly once the foliage has filled out. Actively growing plants will also benefit from a couple of liquid feeds during their growing time; use a balanced organic fertiliser such as seaweed extract.

Growing Potatoes in Containers

Buy your seed potatoes as soon as you can and break them free of their nursery bag or net. We’re going to sprout them first – a process known as ‘chitting’ by the potato gurus. Lay your tubers with the majority of ‘eyes’ facing up. Place them into a supportive container such as an egg box and keep them in a light but relatively cool place to produce stubby, dark green shoots. Don’t obsess too much about this process – the idea is simply to keep the tubers fresh until you are ready to plant them. This can be from very early spring if you can offer some protection from frost, or mid spring if not.

Add some additional drainage material such as crocks or broken up polystyrene to the base of your container then fill with about 10cm (4in) of your growing medium. You have a few options here. Multipurpose compost works well, but I bulk this out (mainly to save money!) by mixing it with good garden soil and some of my own garden-made compost. You can also add a couple of handfuls of organic fertiliser, such as chicken manure pellets, for good measure if you wish.

Earth up potatoes as they grow to increase the harvest

Space your seed potatoes, sprouts uppermost, evenly throughout the container. Cover with another 10cm (4in) layer of growing medium then sit back and wait. As the shoots grow continue to add further layers of potting medium until you reach within a whisker of the rim of the container. Remember to water and feed once or twice with your liquid feed.

When to Harvest Your Potatoes

It’s hard to judge the size of your potato crop from above, so plunge your hand in and have a root around! The first tubers will be ready to enjoy soon after plants come into flower. Feel for the tubers, pulling free any that have reached the size of a hen’s egg, or allow them to grow on to your preference. As soon as the foliage begins to die down it’s time to tip out the contents of your container and gather the stragglers. By feeling about like this you will be able to prolong the period of eating, while allowing plants to grow on and swell those tubers that remain.

The best way of serving them? That’s entirely up to you and partly governed by what variety you plant. My absolute preference is firm new potatoes served steaming hot with a curl of butter sliding over them, all topped with a generous sprinkling of garden-grown parsley. Pure heaven!

By Benedict Vanheems. Potatoes in buckets photo courtesy of Dobies.