If you grew potatoes last year, you may be surprised to see some potato plants appearing in your plot. Known as volunteers, these plants grow from tubers left in the ground. Many gardeners, on seeing volunteer potatoes for the first time, wonder whether or not they can grow them and eat them, or whether they should pull them up.
Our advice is that if you grew potatoes without problems with blight, then there’s no harm at all in leaving them to grow – they are more than likely to be fairly healthy plants. Of course, they won’t be growing in neat rows so your raised bed might look a little higgledy-piggledy (nothing wrong with that!) and you may find they have a lower yield. Still, if you don’t mind them growing where they are then you may as well leave them to grow and dig them up when you see flowers forming on the plants (unless you know for sure that they are a maincrop variety in which case leave them until the foliage dies back.)
On the other hand, if your potato crop was infected with blight last year, then it is probably best to dig up any volunteers and remove them. Since volunteer potatoes can grow from any old tuber – a rotting one, a tiny one, one that’s broken, even a bit of old peel – they can also grow from blight-infected tubers. Blight spreads so easily and it’s not worth the risk of infecting any healthy seed potatoes that you might be sowing.