Posted: 14/06/2017 at 18:00
If you can get some capillary matting you could use that. I put my pots in a large tray with capillary matting in the bottom with a shallow layer of gravel over it. The other end of the capillary matting is put into a bucket or trough. The matting will draw up water as required.
I would also make sure the greenhouse is left open and some sort of shading erected.