Saturday I weeded the potato patch thoroughly. On Monday, 9 of the plants (of about 50) were looking like this. Oh no! I was most concerned that they might have some sort of blight, especially as they weren't proper seed potatoes, but just a bag of maris piper sold for the pot from Lidl.
But then, I thought, maybe I damaged the roots when I was weeding on Saturday? I was pretty thorough, let's say. (Though, now, I can see that a wee bit of root damage would be unlikely to cause such foliage problems.)
I tweeted the photo this morning, and first one, then another twitter suggested frost, so I checked out the Glasgow temperature records. It was indeed down to 3C over the weekend. So, clear sky, it could have been a frost.
Which is a relief, it's NOT some sort of blight. And I've also learned that when BBC Scotland weather warns of the "possibility of frost in sheltered glens in rural areas", that can also mean the east end of Glasgow. If I'm planting out particularly tender plants in future, I should be aware of the possibility of frost in mid-May.