By Manfred
United Kingdom 
I have sown potatoes for xmas in bags and after few weeks put them in my greenhouse and the shaws have turned black. Why I stay in Scotland the Fife area.
On plant
Duke of Yorks
17 Oct, 2011
Answers
Sounds v much like frost scorch. Could it be sun through glass Mg? My DoY leaves didnt like it,& they were in veg plot.
17 Oct, 2011
Not knowing where in the UK Manfred is makes it a little difficult to answer. I'd go with frost rather than sun though.
17 Oct, 2011
This summer I had an excellent crop when I grew potatoes in bags. This encouraged me to have a go and grow them for Christmas using the conditioned tubers from my local garden centre. I'm afraid, they took off well, but contracted potato blight, the foliage turned black and shrivelled. Could this be the answer?
17 Oct, 2011
Have you had a frost and would the shaws have been frosted?
17 Oct, 2011