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Should I use clear or white polythene for tomato & bell pepper growing, which will be the main crops in my greenhouse. Also, which would be best for general purpose seedling growing until the plants are ready to put out. I'm growing virtually everything you could think of, so the best generic product would be best. Thanks

I'm not sure I understand your question, JT. Do you use polythene inside the greenhouse or is it a polythene covered one?

I've never used polythene in the greenhouse but, depending where you live shading may be necessary. Not a problem for me I'm afraid

Inside the greenhouse as a secondary layer.

As I said, I've never used it inside a greenhouse. What do you want it for? Is a second layer necessary?

I'm not sure what you mean either, JT101.

I'm a confirmed tomato and chili (read bell pepper) greenhouse grower, and I'm pretty successful - normally - using just the normal greenhouse controls of opening the vents and the doors. I'm fairly bang smack in the middle of England, so I suppose you may have to change what I've said depending upon where you live. But tomatoes and peppers have been grown in this country for donkey's years without any special methods other than glass cover.

Mike

Ok. I've had a day to view the results of what I've done. I guess I got a bit confused actually. When I started all this secondary "glazing/insulation" on the inside of my glass greenhouse it was cold and wet, espeically at night. Now I'm just finishing it, and this hot weather has come. My greenhouse is unbearably hot (at least for my seedlings). Has killed many of them.

I think I'll remove the polythene I had (which was white), and replace it with some shade cloth. I'm planning on eventually growing tomatoes, peppers, and cucumber eventually once all my seedlings go out. Presumably then I should take the shade cloth down as tomatoes love the sun. Any thoughts.............?

Come winter time, I guess that is now what I should be considering. You want to get as much of the limited sun as possible to absorb and trap that heat. In which case I'm sure clear polythene as a second internal layer would be beneficial to trap the heat. Unless of course bubble wrap is better overall even though the light conditions are limited.

You could just use that window cleaning stuff (assuming they still make it) - the stuff that goes on like paint? I've seen greenhouses with something that looks remarkably like that shading their crops - then when you wash it off you've got a clean greenhouse too!

I heard of people using bubble wrap for insulation but, depending on what you want to use the greenhouse for over the winter, it may not be necessary.