Alan Titchmarsh explains how to grow potatoes in a bag. He demonstrates how to chit potatoes and how to plant first early varieties, such as ‘Red Duke of York’, ‘Lady Christl’, ‘Orla’ and ‘Rocket’.
How to grow potatoes in a bag
Roll the sides of the potato bag down so it’s just under a third of its usual height. Add 10cm peat-free compost to the bottom of the bag and place three to five chitted potatoes on the surface. Cover with another 8-10cm of compost and water well. When the shoots have grown to around 8cm, ‘earth them up’ by covering them with another 10cm of compost. Do this every couple of weeks, gradually rolling the bag back up to its intended height. This stops the potatoes from being exposed to light and developing green patches.
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How to grow potatoes in a bag: transcript
There is nothing more exciting and more fulfilling than growing a few vegetables, but if you’re limited in terms of space, you really have to think very carefully about what crops are worthwhile in terms of both labour and production. And first early new potatoes are brilliant in a small space. Now, I say first earlies, first earlies
are the ones that mature most quickly and in a small space, you want a yield that comes fast, rather than waiting for absolutely months. This is a potato variety called Accent. It is a first early and it’s been chitted. That means it’s been sprouted. The eyes on these seed potatoes – and always buy seed potatoes because they’re guaranteed to be virus-free, rather than ones that have just sprouted in the cupboard under the sink. These, when they’ve been chitted, will crop that little bit earlier, rather than planting them with just plain ordinary eyes on them, rather than little shoots. So, chit your potatoes. They’re going to take a good month, six weeks for those sprouts to come up. So you can start some January, February, early March. The sooner you start, the sooner you can plant and you can plant them quite simply in a bag like this, or in potato grow bags if you want. But the great delight about planting in this is that you can earth up – more of which in a minute.
A bit of compost in the bottom. This is ordinary, peat-free compost. I’ve got about three or four inches in there and I’ll space out these sprouted, or chitted, seed potatoes. I can get about five in there I reckon – I’m a bit greedy. Some people only put three but I want as many spuds as possible. So rather like the face of a five dice, there they are. I’m then going to put more compost on the top, about two or three inches, making sure they’re underneath it; and as soon as those shoots start to grow, I’ll be earthing up a bit more.
But where are you going to put this now you’ve done it? Sheltered place, light place. If you really want, if you’ve got a cool greenhouse and you want to get them shifting. You can put them in that. A greenhouse, porch or a carport, somewhere sheltered but in good light. And when those shoots start to appear through the surface of the compost and they get up to about three inches, add a little more, all the time, until you’re about halfway up the sack, because what you’re doing is making sure that those tubers don’t get to the light. If the light gets to them, they’ll go green, they’re nasty tasting and actually poisonous. Not something you need worry about, because soon, when you’ve got the compost up to here, you can let them go. And the foliage on the top will get absolutely enormous. And in about eight to 10 weeks time, after you’ve planted, that’s when you can scrape away that compost and see what’s underneath. Don’t be too greedy. You’re not going to get socking great spuds, you’re going to get lovely new ones that will be fabulous – cooked in a pan with mint and floating in butter. Well, that’s why we do it, really, isn’t it?