Kitchen Garden Forum

I transferred my tomato seedlings to an unheated greenhouse late last week. Initially, I was concerned that they might get a bit chilly overnight, but this seems to be fine. Quite the opposite has happened and they appear to have sunburn - the leaves have white scorching on them.
As well as the tom seedlings, I have a number of other things growing in the greenhouse. These include pots of mange tout peas, potted on basil, cucumber and butternut squash seedlings. The toms are the only plants with scorching and are otherwise doing well. The basil is looking particularly enthusiastic.
The greenhouse is polycarbonate with a diffusing roof but clear sides. As it's still early in the season, I'm reluctant to have to put shade into the greenhouse, but wonder if I better had, even though all the other plants seem okay. Also, the daytime temperatures are forecasted to decrease next week, although it may still be hot in the greenhouse as it's southerly facing.
Any thoughts, anyone?

Do you wet the foliage when you water? Tomatoes are much better with all the water going on the compost and the foliage kept dry, stops burning through droplets and reduces fungal problems.

Could you not put some fleece over the most sensitive plants? They will still receive the light but not the direct sunlight.

I've currently got green mesh draped over the side that gets the late morning sun, as it gets quite hot in there, it's been almost 30 every day this week. A couple of weeks ago, it peaked at 41!

Thanks, chaps. The young plants are all watered from below, sitting in seed trays of water except for when they get their evening splosh. I think it's probably whilst the toms are small, so I will give them a little shade but leave everything else as it all seems okay. It got up to 37C yesterday, with the doors and window open. Phew!