Easy Greenhouses

I thought this would be a good place to discuss simple grow houses and greenhouses. I’m going to suggest a way to get a reasonably priced grow house that can be expanded easily as well.
This is the Harbor freight portable garage.
I have one that I store junk in that has lasted 7 years now. They can be assembled in an hour or two and are surprisingly sturdy especially with a little added interior bracing. some extra framing would be necessary for the end walls and doors but that could be easily done with wood or PVC pipe. Some sort of raised beds would secure the base and add rigidity.

A cover could be made using reinforced 12 mil tarps.

I have had one of these tarps on the roof of my greenhouse for 6 years now and it is still flexible. The reinforcement is a plus since I’ve had a branch that punctured mine but didn’t made a large rip and was easily patched with poly tape. The fitted cover made from the tarps would be taped at the corners as well.

10 foot wide is a good width for a small grow house. It allows you three foot beds on the sides and an a wide aisle down the middle.


Hi Tom , your doing real well getting that tarp to last you 6 years that for sure and i guess that’s because its made with polyethylene rather than polypropylene , both work but Polyprop does not have the flexibility of Polythene , that’s why the run of the mill tarps here in Australia all seem to be made out of Polyprop and are lucky to last 2 winters before degrading and rotting away .


How does the HF garage do with snowloads? Do you put in extra reinforcements during winter i.e. poles in the middle?

Edit: it does not show that I answered Tom on my post so perhaps I accidentaly hit Dave’s reply.


We normally get a lot of snow Johan. Average has dropped the last few years but average is normally 165 inches a year. I have some benches set up on the insides so that keeps the sides from moving . I ran a line of 1x4’s half way up on each side of the rafters to keep the cover from bowing too much and I have had at least 6 inches of snow on it before I cleared it which just takes maybe five minutes banging on it from the inside with the bristle end of a shop broom. If you added a bottom chord to the roof framing and a few diagonals it would get much stiffer and since it is a greenhouse, adding a few columns on the face of the raise bed boards and a run of 2x4’s under the top chords of the framing would make it real strong. I haven’t done any of that on the one I have and it is still holding up fine.