Thomassio wrote: I'm trying to figure out what to do with my makeshift greenhouse, polythene creation. As the weeks have gone by and the sun has changed, it now doesn't get the sun until about 11:30. It wouldn't be a problem in a proper greenhouse I'm sure but as it's 'well ventilated'! It's temperature can range from 12 degrees at night to 42 in full sun! I'm taking care to open it when it gets too hot but I would still rather have it get sun through the day. Any comments from anyone?
When I moved to my house, the patio was in full sun and I planted out lots of pumpkins and other sun loving plants to take advantage of the sheltered spot ... then the neighbours ash tree burst into leaf and everything was in perpetual shade LOL. My garden is surrounded by trees and tall hedges so my greenhouses and polytunnel only get full sun from about 10.30am - 5.00pm in midsummer and the plants seem to do fine. Last year I did find the chillies needed as much sun as possible, but most other plants were okay. You could perhaps grow plants that can tolerate some shade such as salad leaves.
As for temperature swings, all greenhouses and polytunnels get hot in full sun and need the doors and vents open, and then closed in the evening to keep as much heat in. With the recent cold wet weather with sunny spells, it's a difficult decision in a morning what to do when leaving for work: do I open the doors and the sun doesn't come out and it gets too cold (some daytime temperatures have been about 12oC) or leave the doors closed and risk it getting too hot when the sun comes out unexpected. Small greenhouses (like those cheap 2 or 3 tiered) are notorious for getting too hot if the door isn't unzippered, whereas large volumes of air in a greenhouse warm up more slowly and cool down equally more slowly in comparison. In greenhouses, there is also the risk of scorching especially when the sun's strength is particularly hot - some methods involve painting cool glass (a sort of white wash) so that light is more diffused, or putting a temporary net which is basically shading on the roof (like they do in hot countries like Spain to protect crops such as tomatoes from being cooked)