What causes beans to go yellow and weedy ?

[rustylady]

Lord Marb, it's like pulling hens' teeth.

OK it's a large tub, how many plants are in there? You say you have runner beans and french beans in there - what varieties and how many of each?

[veggiechicken]

Is there any chance of a photo of the pot, and the beans and the pods?
Doesn't sound like a very large container unless you only have a couple of runners and frenchies. How deep is it?

[Two_Sheds]

Why are French beans so hard when runner beans are so easy to crop?

French beans like hotter weather. I seem to remember that your garden is quite shady?

[Potstubsdustbins]

Any more than four plants in that container and you could expect trouble. My personal preference would be three and only then if it's at least 12"/300mm deep.

Potty