How to grow potatoes in bags

Potatoes are fun to grow. They only need four or five hours sun, you can get a reasonable crop from a bucket sized pot (1 - 2 kg / 2 - 4 lbs), and, if you have kids, you will have great fun harvesting them together!

What sort of pot?

Potatoes do well in bags - bags for life are ideal - as you can roll up the sides as they grow. But any pot that is bucket size or bigger will do (just check it has drainage holes).  

Bags for life make ideal containers for potatoes. Roll the sides up as they grow.

What type of potato?

"First Early" and "Second Early" potatoes (as gardeners call them) are best in small spaces as they mature fastest (usually ready in 10 - 12 weeks after planting).  They will also give you delicious new potatoes, that taste amazing freshly picked. But it is also possible to grow Main Crop potatoes. They will need larger pots (ideally 40 litres or more) and will take longer to mature (around 15 weeks or more).

Only one seed potato needed in a small bucket. These are different varieties (mostly Earlies) - you can see the harvest from each of these buckets in the photo at the top.

How to grow potatoes

1. Add 8 - 10 inches (20 - 30cm) of potting mix to the bottom of your pot. Potatoes are not too fussy and will usually grow ok in old potting mix as long as you add fertiliser (a handful of blood fish and bone or other general purpose fertiliser will do the job).
2. Put your seed potatoes on top  (one seed potato in a bucket, two or three in a large bag for life, 4 in a 50 litre container), then cover them with a further six inches (15cm) of compost.
3. Put them in a sunny place. They need at least four hours sun - the more the better. Then water once to make sure the potting mix is damp.
4. Water as needed in the coming days to keep the soil damp (but not too wet - or the seed potato can rot). Green shoots will usually appear after three to four weeks.
5. When your potato plants are about a foot tall, roll the bag up about six inches and top up with potting mix. Keep doing this every couple of weeks until the bag is completely unrolled.

Roll up the side of the bag and top up with potting mix as the potatoes grow.

7. As the potato grows bigger, check more regularly for watering.  Baby potatoes may only need watering once or twice a week, but mature potatoes (when the leaves are big and bushy) can need watering once, even twice a day, particularly in hot or windy weather.

When to harvest

Flowering is one sign that your potato might be ready for harvest. But the only sure way to tell is to put your hand into the soil, rummage around a bit, and pluck out a potato! If the potato has reached a decent size, it is ready, if not, leave for a week or two longer. If your potato hasn't flowered after twelve weeks - check anyway.

The small flowers on this potato (in the foreground - hard to see - not the plant with lots of yellow flowers behind!) are a sign it might be ready for harvesting.

How to harvest potatoes

The easiest way is to tip the whole bag out and go through the compost to find the potatoes. (Kids love this!).

Your turn

I'd love to hear your tips for growing potatoes in containers in the comments - and any varieties that you particularly like to grow?