potatoe problems

this year I have grown potatoes in containers and have plenty of healthy growth on them all. Last week I noticed some dark brown spots appearing on the leaves of two of my containers and yesterday I noticed from a distance that the colour of the growth on these two are slightly yellower that the others. I have 6 pots in a row and the spotty two are not next to eachother. The others are healthy. Any ideas what the problem is. Can it be be corrected or is it terminal.

Brown spots can mean anything - perhaps a photo might help.  I'm inclined to think the plants are naturally dying back and the spuds are ready for harvesting but I really am only guessing.  It could be the 2 plants have been a little short of water at some point especially if grown in pots and got a bit pot bound.

What variety did you plant, and when did you plant them?  If my guess is right, you could have a furtle (gently dig down with your fingers until you come across any tubers) to assess the size of the potatoes to know for sure.

Thanks Babbyanne. You were right. They were starting to died back naturally and have yielded some great spuds. Thanks.