# Greenhouse - Clear or Opaque - Which is best?



## Honeybee (Oct 16, 2002)

We're building a small greenhouse and I am trying to figure out which is best for our needs, clear or opaque plastic for the outside?

We are pretty far north, maybe an hour or two from the Canadian border, but we get some scalding summers, but being so far north our growing season is also short.

Besides starting as much as I can we hope to use the greenhouse to keep a few things going as much through the year as possible and maybe even grow cool weather greens most of the year.

I have no greenhouse knowledge what so ever so any suggestions would be appreciated :grin:


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## oregon woodsmok (Dec 19, 2010)

No opinion on the cover, but get yourself some shade cloth to throw over the greenhouse for days with intense sunlight and too much heat.


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## Wolf mom (Mar 8, 2005)

The absolute best is the old uncoated glass or polycarbonate. If you're planning on extending the growing season, you need to capture solar energy to heat & for plant propogation

You can always vent the GH from the top if it gets too hot in the middle of your growing season. Or use shade cloth. 

A really good book is The Solar Greenhouse Book by James C. McCullagh. Even if you're not going to go solar it's one of the most educationally inclusive books I've found.


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## Marcia in MT (May 11, 2002)

Clear. Because you want to use this in cooler weather, you'll need all the solar gain you can get. So opaque is out, since it blocks sunlight.

However, you will need to cool the greenhouse at times, because they are such wonderful solar collectors. When the sun is out, even in subzero weather, we have to vent ours. So for shading in the summer, you can:

Buy shadecloth and cover the outside of the structure (this is what we do);

Figure out another kind of covering -- I've read of people spray painting plastic with silver paint and putting it over the outside;

Paint the outside with whitewash, or some other kind of paint that can be washed off in the fall.


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## Honeybee (Oct 16, 2002)

Thank you very much for the replies, you all given me a lot to think about


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