I have a small plastic greenhouse and I just put out my tomato plants a few days ago. What are your night temps? Ours are in the 50's by now. What kind of plants are we talking about? Annuals, veggies or perennials?

What type of glazing does it have? The flexible plastic glazing provides almost no insulation and it will get very cold at night. Glass provides some insulation, twinwall polycarbonate has more. If you have glass or polycarbonate and the greenouse is sealed so no major drafts then you are probably OK. Put a max/min thermometer out there. If it stays above 50F at night, most stuff can go out. Watch out during the day, it will heat up very fast.

...additionally,noting the above posters,you should have received written instructions/sugestions from your distributor/ product manufacturer ...too many variables...afterall,it is your hard earned cash...(this is unacceptable)...

furthermore...I don't know if the product has much merit or whether I judge this as another needless accutrement...I'm rather irate here as a consumer...

Below is the web site and what it looks like. So far all is growing well. Most are marigolds and some that have come up from seed. I did put some of the lavender in there also. I called the company for no, it doesn't tell you how to use it and I wasn't too sure.
Deb

http://www.growerssupply.com/webapp/wcs/stores/servlet/ProductImageView?catalogId=10551&storeId=10001&langId=-1&division=GrowersSupply&magnify=104696a.jpg&imglist=104696a.jpg%7C

Here is a link that might be useful: Greenhouse

I found the tiny bit of info they have about it on the site. (See below.) -It says it is not stocked and to call for info, so you might be able to get some instructions by calling the "Contact Us" number.

Here is a link that might be useful: Patio greenhouse

thanks Deb...it looks like a tidy set-up and the top vent is a nice feature.I would install a min/max thermometer and hydrometer alarm.You'll need to figure out its limitations i.e.bottom shelf), usefulness, and sun exposure.With the addition of a shade compound: a rated shade fabric or liquid shade in key places,you might control the heat a bit with the combinations of the vents.Continental Paints manufactures greenhouse shading compounds (Kool Ray).some are designed for poly/fiberglass structures...Also,using a Drumel cutter, one could add another vent or two...
goodluck

You can also moderate cold temperatures by filling 1-gal. jugs with water and setting them on the bottom shelf (or ground), and if it's going to get REALLY cold, tossing a couple strands of lit indoor-outdoor miniature christmas lights in the thing. I'd probably be lazy and just prop the doors open (with the handy dandy water jugs--also makes watering convenient) and the roof open with either an attached bar (if there is one) or a handy stick in warm weather.

(I'm definitely a low-tech person)

Thanks for all of the info. My small greenhouse is working great and is full. The company doesn't sell them anymore so my husband ordered a larger one that arrived yesterday. At least now I have room for all of the plants growing in m dining room. I just can't wait to plant them all!