Broad bean leaf gone black!

[Garden50273]

I'm growing a broad bean for a school project (tallest wins) but theres a slight problem,
its Quite high now and the leaves are turning black (only some) on the edges. Is it okay?

[Aberdeenplotter]

I suspect that it is simply succumbing to nature at the end of the growing season. can you let us see a photograph of the damage to the leaves please?

[chris]

Are they outside, under cover or inside? Where about are you based - if you're neighbours with AP you may well have had a nip of a frost, yet if you're further south it may be something else if you've not had a frost yet.

[Two_Sheds]

Black leaves = touch of frost

You may end up losing all the foliage. Cut off the burnt bits, more leaves will regrow (the root doesn't die from frost, not usually).