All my greenhouse cucumbers have developed a white wooly growth at the base of their stems. The plants are wilting and seem to be dying. Anyone know what this is?
That sounds like stem rot, Geoff. It's a fungus and is always fatal as far as I know, unfortunately. Next year you can lessen the chances of it happening by planting them on a slight mound of compost so that water runs away from the stem. Also take care not to overwater them, especially when young. More here:
Thanks Bob, that's useful to know. I think the over-watering might be the cause. Good to know for next time.