[marigold]

Help - my prolific cucumber plants in the greenhouse are wilting before my very eyes.  The greenhouse has two open roof windows and I have left the door open because of the heat.  The glass is whitened and I have damped it down every day.  Yesterday the plants started wilting before my eyes and I wonder if I have overwatered them.

[Fisherman]

The most likely cause is stem rot at the base of the plants due to an infection or hungry slugs chewing through part of the stems. It could also be too much water, too hot, draughts etc. Another cause could be cucumber bacterial wilt which is transmitted by the cucumber beetle which is a little stripped devil about a quarter of an inch long. If it is there’s not much you can do once they are infected. The plants will wilt even when they’ve been well fed and watered. If they don't recover cut one of the stems just above soil level and squeeze it, if a sticky, goo comes out, it’s bacterial wilt. This goo cloggs up the plant’s circulation system and prevents it taking in water and hence it wilts.

Hope the plants recover.

[marigold]

Thank you, I shall be going down to the greenhouse this evening - fingers crossed.

[paintedlady]

seems strange that all the plants were affected at exactly the same time whether it be pest or disease.  And as for overwatering ... a possible cause but usually built up over time with repeated overwatering and the roots have been sitting in water for a while.  Overwatering tends to show up with yellowing of the leaves and poor growth - a one day over zealous watering regime is not likely to kill any plant.

I might think it is more likely a physical problem - too much heat is a good candidate for wilting.  The plants are losing water through their leaves faster than the roots can take it up - it's temporary, and providing the compost/soil doesn't dry out, they should recover when the temperatures drop, but repeated wilt will eventually start to affect the plants in the long term.  Perhaps check the greenhouse temperature (a min max thermometer are quite good), and maybe think about providing some shade (you can get special netting or white wash for the panes) as well as providing the ventilation.