Harbor Freight 10 X 12 Greenhouse: Building, Strengthening, Using

A thread to document the Harbor Freight Greenhouses: How to build them. How to strengthen them so that they actually work. How to use them.

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Here's a time lapse photograph taken once per hour starting after 3 hours. Eleven hours labor have been put into the greenhouse so far.



So far the build is going smoothly. It's my second time erecting this model, so it's going quickly. One of the beams was cut 1.25 inches short at the factory. That caused troubles at every stage of the build until we were putting the roof panels on and noticed that one of them didn't fit right. So I wasted an hour measuring what was wrong, getting the spacing right, and drilling new holes. Aargh! The joint isn't as strong as it would have otherwise been, but it should hold up ok.

Here's what the error looked like when we finally got it corrected. Those two beams are supposed to join together snuggly. That big gap is not right.



Winter is coming... Getting the roof on just in time so that I can have a dry spot to work in if it rains or snows tomorrow.

Finished building the greenhouse kit this afternoon. It started snowing about 3 hours later. Two inches of snow have fallen in the past hour.

Riveted the door slider plate to the frame to help the doors slide easier. The rubber seals on the door are too long, creating friction against the frame. Intending to trim the rubber. Just before I quit working on it today, I cut a 2X4 for bolting across the front wall above the door-way. This is to help stabilize the front wall, and helps the doors stay on better in windy weather.

Added a workbench:


I'm using kerosene lamps for supplemental heating. They sit under the bench, which is covered with floating row cover and bubble wrap as needed at night.


Here's what the plants looked like this morning.

I have been debating putting one up also. I haven't decided for sure yet. I have a small greenhouse I built but bending two cattle panels into a hoop house configuration and covering with plastic. I don't know yet if I am better off creating another one of those, or going with the Harbor Freight one. Thanks for posting build pictures.

Here's what was growing in my greenhouse this afternoon.

Tomatoes, medicinal herbs, onions, basil, bok choi, broccoli, peppers, sweet potatoes, onions, lagenaria squash, a half flat of favas that got a late start, etc... I expect to harvest some bok choi in the next few days that is growing as a weed in the soil of greenhouse. (I winnowed seeds in the greenhouse last fall.)

Peas, favas, and onions have already been planted out.

A peek inside the greenhouse today:

We received about 13" cumulative snow in the last couple days.


Different perspective on the same plants.


The more cold-hardy plants are growing on the floor where it's not as warm:


The onions could be planted out any time. The farmer's market opens the first week of May. They'll still be fine by then.

Here's what the inside of the greenhouse looked like yesterday. The farmer's market starts in two weeks, so that'll free up some space.

The greenhouse survived the 3 feet of snow that fell on it, but not the rain that fell on top of the snow. I bent the rafters back into place, and added some reinforcement inside.

Then I observed the greenhouse closely. The glazing is slick as can be, so the snow would slide right off, if it weren't for the rain-gutter which catches the snow and causes it to accumulate on the roof. So I installed roof flashing to cover the rain-gutter. It works like a charm. Here are photos. The right  side was treated, the left side wasn't. I'll be covering the other rain-gutter soon now that I have demonstrated that it makes a big difference.  

The greenhouse survived it's third winter in great shape. No mechanical problems occurred. There is more thermal mass in it than ever. I do additional caulking whenever a leak becomes evident. The roof sheds snow easily. Even though it was heavily cloudy today, the temperature inside was 23 F warmer than outside at mid day. Currently, hours after dark, the temperature is 8 F warmer than outside.

I'm not currently adding any heat to the greenhouse, but I expect to in the near future when I start tender crops.