A step by step guide to growing potatoes in buckets and other containers.
Why use containers for growing potatoes?
I grow a lot of my potatoes in 30 litre buckets. They are fantastic and there’s a couple of reasons why. First is you get to control the growing environment. The soil can dry out, it can crack, potatoes get blown, all shapes and sizes. You may have a late frost, but with a container you can pick it up and take it to the polytunnel. Second, you can start them early if you want to. You can put them in the polytunnel and as soon as the plants start showing above the compost level, get them out into the sun, providing you’ve got good weather and is no frost forecast. Third, your crop will be there much quicker. You can actually speed up your harvest time because the black containers absorb less sun so it helps the plant to take up the nutrients much faster.
What if I you don’t have a polytunnel?
If you haven’t got a tunnel you can use your porch, your garage, you’re only putting them there overnight or you know for the day that that frost risk is there, once a frost is gone you can put them straight back outside and they’d be fine.
Use a really good compost, that is nice and light, with no massive pieces in it. This helps the roots to penetrate through easily. Put a good couple of inches of compost in the bottom of the bucket. The buckets I use are 30L and have got four big holes in the bottom, as well as holes right around the circumference are holes, which will aid in drainage.
Do I put broken crockery or rocks at the bottom of the container?
You do not need to put any stones or anything down in the bottom of the container. The potatoes will send roots out through the bottom of those holes and it’ll work down into the ground. So if for any reason that you forget to water you get the best of both worlds.
Feeding potatoes grown in containers
You can add a bit of feed to the first couple of inches in the bottom of the container. About one and a half ounces in the bottom and mix it in. You could also add one and a half ounces of pelleted potato feed, it’s organic and the NPK on this is 6 .10 .10, so it’s really good for potatoes. This is going to encourage the tubers. When you’re looking at any potato feed you want to have nitrogen to start with, but not too much and then you need potassium in there, so get a good 10 and above for potassium.
What if the potatoes get too much Nitrogen?
Last year when I grew my potatoes in the chicken bedding, so had a massive amount of nitrogen – the tops were huge at about four feet tall of top growth, but not a lot of potatoes at all.
I chit the potatoes. but the reason I do is because I’m just itching to get growing something. You don’t see farmers growing chitted potatoes in tubs. Farmers just plant them without chitting first, but the soil is always warm before they plant their potatoes.
My seed potatoes have really long white shoots, what do I do?
The only way to deal with that is to snap them off and re-chit the potatoes. Last weekend I found some potatoes that I’d had in my kitchen and I had forgotten about. They were in a dark container and they were in the warm. All the conditions that you don’t want for chitting your potatoes. They have got about 1 foot long stems on them because they were desperately seeking light.
The potato is looking for light, so when you’re chitting them you have to keep them in a really bright place and it’s got to be cold, but frost free. They should have very small green growth and that’s what you’re looking for.
Planting seed potatoes for growing in buckets and tubs
With first and second earlies you can put four seed potatoes per one 30 litre bucket, with main crop you only want two in there. First and Second early potatoes don’t get that big. Using the extra two seed potatoes in the container to makes best use of the compost. Set two seed potatoes down into the soil opposite each other and then cover it over a couple of inches again on top of that to about halfway up the bucket.
Should you only put a little layer of compost on and then fill the container up as the plants grow?
When you grow potatoes in containers, you could break the plants as you add more compost and that will set the potatoes back. Fill the bucket as you plant them. Although it take them a bit longer to come through the compost, you’ll have a much stronger potato plant for it.
To plant the next two potatoes set them opposite each other, but in the space that wasn’t planted in below. So in effect creating a cross, but at two different heights of the container. There is no need to put feed in the middle part, so cover over those potatoes. Fill the container to about three quarters of the way with compost and add the feed.
The reason to add the feed above is because the water drags the feed down for the potatoes to access. Add another one and a half ounce of blood fish and bone and of the potato fertilizer and mix that in. This is enough feed for this number of potatoes for the whole growing cycle. Then fill the container with a little more compost, firm that down gently however, leave about an inch below the brim, so when watering it doesn’t flow over the top.
To test whether you need to water the potatoes in containers, push your finger into the compost and if it comes up with any compost stuck to it, it’s wet enough. But, if it comes out with nothing on, then it’s time to water. Don’t over-water them because they will rot.
Where to grow the potatoes in buckets
Put the filled container in a greenhouse, polytunnel, conservatory or something like that to get the potatoes shooting. And when the last frost has passed, you can put it outside. If there is frost you didn’t expect and they are outside you may want to cover them over with a bit of fleece or sacking to prevent frost damage.
First early potatoes are usually ready to harvest in about 10 to 12 weeks. Second early container grown potatoes in around 12 to 14 weeks and Main crop can be up to 18 weeks.
Further Reading and Information about Potato Growing
Video that accompanies this blog post How to Grow Potatoes in Containers
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