Is this idea realistic for my zone? I am thinking of one hoop being about 30 inches high, and the outer hoop about 3-3.5 feet high. This would be a 4 foot x 8 foot structure, made out of PVC and plastic. I don't expect it to last more than this single winter, and if its effective, I might try something more permanent in the future.

Crop options:

Spinach, lettuce, broccoli, beets

What potential pitfalls are there? Any advice is welcomed!!!

EG

I will probably be constructing it next weekend.

Here is what my plans are:

Interior house:
3/4" PVC cut down 2 2.5 feet lengths, and a 4 foot length, connected with elbow (1/2 elbows, cemented INSIDE the 3/4" PVC) for the supports

4 foot long 1x2's will be connected to the bottom of the PVC on the sides, but the PVC will not be in the ground at all, just resting on the surface. (allowing easier access to the plants!)
The hoophouse plastic will be connected in 4 foot sections half hoophouses, that meet in the middle and connected with large binder clamps). The plastic on the sides will be stapled to the 1x2 at the bottom of the sides, and the end of each half-hoophouse will be clamped closed at night, and opened in the day, according to the temp and sunlight forecast.

Exterior hoophouse: (this is where it gets trickier)

3 foot rebar driven into the ground every 2 feet, on both sides. (driven into the ground 2 feet, leaving 1 foot exposed, for the PVC to go over).

I figure to use 3/4 PVC for this as well, and just bend a 10 foot length, from one side of the rebar to the other. Again, they will be made into "half-hoophouses" 4 feet long. The end PVCs of each 4 foot half-hoophouse will be connected to the plastic with binder clamps. These will be secured to ensure the plastic fits tightly over the PVC ribs. The middle area of the half-hoophouses will be connected together (somehow...suggestions are welcomed).

One final piece, is to connect the ribs to themselves, with a 1x2 on the end, and in the middle, to keep the shape intact, when removed. This connection can be made at the bottom of the end of the mini-hoophouse, but it will be made at the top of the interior hoophouse for the open end of the half-hoophouse, to allow the interior house to be connected together. (this is the part that is the most complicated, as I see it)

The ends will again be gathered together and clamped closed, and opened as necessary according to the forecast.

Entry into the hoophouse for watering, harvesting, etc. will be trickier than a full hoophouse. First, half of the outer hoophouse will be removed (raised up off the rebar and set aside.)

The interior hoophouse center section will be then uncoupled. Now, the mini-hoophouse can be tilted to allow access to one side. Then, tilted back to allow enty to the other side. And the exterior hoophouse will be replaced.

Then the same happens for the other half. Exterior removed, and set aside. Then the interior house tilted to allow access. Before putting the exterior back on, the halfs will be reconnected together.

Well, that's the plan anyway. Sorry I don't have more information.

Does anyone think it is actually worth the effort of actually connecting the half-hoophouses? Rather than just having them separate, or set up that way, but just not connecting the interior halves, and only connecting the exterior? (this would allow the 1x2 to be connected at the bottom for the middle to help hold the form when removing the exterior house.)

He's in zone 5 I believe. I'd really recommend checking out that book as he also talks about how much longer it takes for things to grow in that environment, and gives some examples of dates and things compared to what they see during the summer.

-Hambob

I will definitely brush off my library card!

The only problem I have in zone 7 is remembering to start the seeds way early in the year (like August, early August). The hoop house protects the plants just fine but with such short days in mid winter seeds don't tend to sprout. Anything started earlier will survive the middle of winter but don't expect a lot of growth, that happens when days are longer.

You can go to HD and get 1/2" conduit for less than 3.00 for 10' and use the leftover for purlins (which I'd use for overwintering in that Zone to keep snow from collapsing and too much flapping in wind). I take the extra pipe and cut it down for clips to hold fabric.

I can get to ~Christmas with poly hoops, dark-colored water in jugs and heavy row cover. Only issue is heavy snow with non-metal pipes and UV degradation, but you can use them to work out your anchoring system and move on to conduit.

In that Zone I bet you can overwinter with a double hoop system, or just two layers - one on either side of pipe - as long as you can vent on the hot days and cover on the real cold nights; your plants will get used to the cool temps better than the heat and will need to be vented.

Dan