It will be warm during the daytime, but at night it will be about the same temperature as outside.

Lots of ideas and pics of structures over on the Greenhouses & Garden Structures forum.

Dave

So, being against the side of the house won't help it retain some extra warmth at night? I figured that since the house already helps to protect the stuff that's really close to it (I've lost tomatoes on my outer rows while the ones near the house were fine through several Fall frosts).

Lol, there is a forum for EVERYTHING on GW! Heading over to the greenhouses forum for more info and ideas... thank you!

I think this form of greenhouse would help you more so in summer going into winter. Your ground will be warm, and this will help stop early frosts, prolonging your season.

Not sure how it will work in spring, as you will be fighting cold ground, and having it frost will likely still cause issues even with a sheet up. It might get you a few additional weeks, but I wouldn't bet on much more. I know being in WI I would do a coldframe vs this.

What are you going to be planting in there? Start off with frost-tolerant cool-season crops. Plant your frost-sensitive crops after your last frost date, and then yes you can erect a structure utilizing row covers covered by plastic on the outside.

It will make a big difference if you're talking about a south-facing wall. If so, and especially if that wall is brick or concrete, it will make a big difference at night. It will hold a lot of heat. I too see that plants closer to a brick wall are more likely to survive a frost. Now, in order to give that protection, the plastic has to be reasonably well sealed. You don't want big holes where the wind can blow into. Such a structure would lend itself well to artificial heating (as in, incandescent lamps), if you're desperate.

It's actually east facing and the house is sided, not brick. Thanks for all the info. I'm not trying to plant early, just worried that with the cold Spring on its way that we'll have more frosts, later in Spring than usual. I don't want to put my tomatoes out a week after the normal spring frost date just to have a really late Spring frost kill them bc this Spring is predicted to be much colder than normal. Trying to be prepared is all. What is a gardener to do when they plant 'on time' and then some random Spring frost threatens their seedlings? Just throw some garden fleece over them and hope for the best?

I'd have to say that siding, which is over wood framing and insulation, won't hold much heat. In fact, if your home insulation is any good, you won't benefit from the heat in the house much, either.

Seems to me the best plan might be to set the plastic up as a low cap over the bed. Then what you're holding in is the heat from the ground. Maybe staple the plastic to a 2x4s on each side, and lay it over the bed, with supports between the plants (big cans? small pails? bricks?) to keep the plastic from touching the plants. Anchor the other two sides with 2x4s just laying on the edge of the plastic. Basically a mini-greenhouse. Now, that design doesn't permit easy access, though access is just a matter of unanchoring the sides, and pulling it off.

If you want to get fancy, fill those big cans or pails with water. That way, you fill the space more with stuff that holds heat.