[Muddywaters]

I think I have red spider mite on my cucumbers in my GH. The tops are covered with fine web and tiny critters. I've washed them off with the hose pipe, but should I get rid of the plants? Will they spread to other plants, toms, peppers, melons? Advice welcome

[Dr_Pepper]

Yes they will spread and if you have webbing you are at a pretty advanced stage of infestation. I would remove the plants, or at least the bits with the webbing on, and then spray everything in the vicinity with a relevant approved insecticide. Something soap-based is good. Avoid anything containing pyrethrins as this may actually make the problem worse. If you don't have one already I'd spend a couple of quid on a 10x magnification lens so you can see if you manage to kill them.

[Springlands]

Muddywaters - you need to keep the greenhouse as humid as possible to discourage the red spider mite - especially as we have had such hot and dry weather recently. Try to water the staging and the flooring on a daily basis and if possible place a basin of water in the GH near the cucumbers as that will help to raise the humidity.

[Muddywaters]

Thanks. Made the decision to get rid of plants before contamination of others. It's going to chuck it down in the next few days so I don't think humidity will be a problem!