I often hear of people making clips from black poly pipe. Cut each piece about 8" long and make a slit along it's length.

You can purchase plastic clips used for rollup sides to clip plastic onto rollup pipe, but because the clips pretty much surround the pipe, I doubt they will work for you. It appears that you want to keep the structure very simple but I'd suggest using a "C" clamp to attach(screw) the PVC to a 2x4" (preferably treated) wood base. Then you can attach the plastic by a number of conventional ways; eg.: 1. wire-lock 2. Spaced-overlapping wooden strips 3. Stapled batten tape over plastic.

A cheap alternative is to simply burry the plastic along the sides by shoveling soil over it along the entire side. Clipping on the end arches is then still an option or you could close the ends by tying the plastic(extending at ~2times the height beyond each end) in a bunch and securing it at the ground with a heavy stake. I usually do this with remay fabric over a canopy frame and it works pretty well. I should mention that I purchased plastic clips for holding tarp onto 1" canopy frame this fall and I can't recommend them. They are very expensive for a plastic clip; they have a tendency to break when stretched over the pipe and they weaken the material even to the extent of tearing it.

BigDogue -- Thank you so much for the tip about the black poly pipe. I have some of it lying around, so I can try this now. I'll describe the problem a little more clearly below and will really appreciate any other input or suggestions you have.

bmoser -- I looked up wire-lock systems, and they seem perfect for securing plastic sheeting to a wood or metal pipe base, but this is a temporary structure that I only need for this winter. This property is being sold and the new owners are allowing me the space for this greenhouse until I established at a permanent location for my rapidly growing (but still in start-up) rare plants business.

The sale of the property, including the good greenhouses I've been using, was unexpected, so I am scrambling to save my plants.

For now, I have driven 6' rebar a foot or more into the ground, spaced 4' apart, and slid sun-resistant pvc conduit over the rebar to make the arches. There is one central purlin. There isn't time (with the first freezes setting in) to build wooden ends, so those are also stretched plastic.

I have bought 6 mil. plastic sheeting in 10'x 25' rolls. The arches are exactly 25', so there is no extra for burying. I'm thinking I'll staple the bottom to scrap lumber with batting strips.

HERE'S MY REAL PROBLEM: (1) I need to secure sheeting to the ends (which, in this location will have to take a good bit of wind). I will try the black poly pipe clips BD suggested, and I'm open to other ideas.

(2) Then I need to secure the first sheet to the end arch. Again, the black poly pipe might work.

(3) I need to connect the successive plastic sheets together over the arches every 10 feet. I donÂt see how the poly pipe clips would work here. Right now, all I can come up with is pulling the overlaping sheets together on the inside, folding it over and stapling it in a fold of denser plastic (milk carton) as batting.

(4) IÂm not sure how IÂll manage an entrance on the other end  maybe just overlapping flaps.

(5) For heat, I have a 2Â tall, forced-air, electric heater and a portable, electric, oil-filled radiator. I can put a box fan behind the radiator to circulate the heated air. IÂm concerned that plain radiant heat would go straight up and dissipate through the cold plastic. Any input on these ideas?

IÂm putting down black ground cloth, which might help keep the ground warm. Is it better to put plants directly on the ground, so theyÂd get ground warmth, or to put them on pallets and benches to benefit from warmer air circulating above the ground?

IÂll be grateful for any helpful ideas.

(bump)

These snap clamps work like a charm and A to Z Supply is super easy to deal with. I have ordered from them a number of times.

Here is a link that might be useful: Snap Clamps

OMG! Thank you for the Pic! I have been struggling with the same question, and searching for answers!

The other possibility if you can't get the right poly pipe is to use Bulldog clips. If you are using 3/4" PVC, the large Bulldog clip, which you can get from Staples or any office supply store, will hold these too.

I put hoops over my raised beds. I found Snap Clamps at Green House Mega Store work well with 3/4" PVC.. I bought the 48" length and cut them 4" each. They fit tight. Instead of using spring clips on the end I used a pipe clamp to attach a 12" piece of PVC then folded the ends in and attached them to the pipe with another piece of the snap clamps.. It works great.

Here is a link that might be useful: GreenHouseMegaStore Snap Clamps

In case anyone else reads this 16 year old thread, to join two or more pieces of covering plastic to make one big sheet, you could melt them together. I'm planning to use a bag sealer, but you could 'iron' the edges together as long as you use foil or paper so the plastic doesn't stick to the iron.