gwoods: The nurseries have no idea what's going on in your greenhouse and probably don't even know what it takes to chill various fruits. Sure it's no problem outside in ID so no one gives it a thought. But outside and in a greenhouse are way different. You need a ~1,200 hrs in the 30s and 40s to chill most apple, peach, and apricot. This year I went 69 straight days between 37 and 57 to get 1270 chill hrs. But my nights are warm enough, ave 30F, that I can heat to ~40F so as to maximize chilling all night long. I think the right approach in your climate is to just heat to avoid damaging temperatures in mid winter. I'd set a goal of maintaining 0F as a minimum. If it goes a little colder that's OK. But all those hrs between zero and 32F give exactly zero chilling hrs. So you need to maintain 30s and 40s on sunny winter days. That will give some chilling in mid winter. In fall and spring you might need to follow my example and heat to 40F to maximize chilling at night. Then hold daytime below 60F because above 60F is actually negative chilling. The meter is running backwards and you're losing chilling. Below 32 at night and 60+ by day is near zero chilling, could even be negative chilling. There are lots of ways to fail growing fruit in a greenhouse. Pay attention to chilling because that's one way to fail. This post was edited by fruitnut on Sun, Feb 9, 14 at 17:27

Sounds like you've really thought this project out thoroughly! I think I follow what you have planned. The main criticism I have is with the 6-mil film you plan to use. Having used 6-mil myself for several years before arriving at the product I use now, I can say that it's flimsy and easily prone to tearing. Commercial gh's that use inflated film covering will use 11-mil on the exterior, and, if they're trying to cut costs, will use the 6-mil on the inside because it doesn't require as much durability. By attaching your film just on the edges of the structure, you'll be asking for trouble. 6-mil stretches, and no matter how tight you pull it, it'll still flap in the wind. Also, with so much potential force focused on a single attachment point along the edge, it'll be prone to pulling free...unless you somehow roll it a couple times around something to evenly-distribute the force. The problem with the wind blowing over it is the element of "lift." Depending upon the wind direction, even with the ends open, the covering will alternately want to rise, then snap back down against the frame. A few hours of windy conditions is all you could ask of 6-mil. Even though the cost is higher, I'd highly recommend the 5.2-ounce translucent tarp linked below. It's 12-mil, and has a woven fabric of fibreglas "tapes" inside the plastic for strength. It's like iron, doesn't stretch, and can withstand just about anything you throw at it. Since it's stronger, and heavier, you'll have less of an issue with it tearing free from attachment points. You also may be able to get away with wider spans, saving you on some rebar. Another plus is the light diffusion through it -- no possibility of burning tender plants/seedlings. I'd have much greater confidence in this material meeting your needs, only attaching it along the edges. The one weakness as I see it for your application is that the largest width available is twelve feet. FarmTek has two products that would be suitable for this purpose. The first one is their Super Tape Seaming & Repair Tape, which is $22.95 for a 3"x60' roll, or $32.95 for a 6"x60' roll. The second is the Premium Repair Tape (product #105383), which is $71.95 for a 4"x100' roll. I'd feel safest sealing both the outside and inside edge, with a 6" overlap of the tarp. Hope your idea for securing the framing against possible racking works OK. If it didn't for some reason, you could retrofit easily with a support line and stake on either end. If you can find a good source for purchasing the wrapping material (to cover the rebar) you described in bulk, that's probably a good bet. I know FarmTek sells something for this purpose, but I'll be darned if I can find it now. The only thing I'd suggest is to use a good-quality tape. I know duct tape is a popular do-all, fix-all, but it performs miserably whenever moisture and heat are present! For this reason, you may want to consider a wire-wrap over the packing material, as an inexpensive material to tightly secure it. Removing the covering in the summer will expose all your handiwork to the elements, so that's another thing to consider. All that work to wrap your rebar may not survive unprotected. Hope there was something helpful here. -Bruce Here is a link that might be useful: 5.2-ounce fabric at FarmTek

cf03, we do what we have to for our trees best interest don't we?.. Some of us have a short growing season and we need to do what works best for our citrus in the long run before we bring them back at the end of the season.. I recently aquired a young Centennial Variagated Kumquat also. It is basically a tall stick with a small canopy at the top. Lol. The nursery where I aquired it shaped it into a tall tree form.. It has no buds yet, but is leafing out a bit farther down the stem now, which I prefer.. Is yours bushy or in tree form?

Hi Vladimir I've had my greenhouse for about 15 years. It's a lean-to off of my living room! The frame is made from angle iron and the cross beams are unistrut. The covering is corrugated clear panels that is sold at homedepot/lowes. Long story short last couple of years I've been growing inside the greenhouse over the summer and through the winter. I live in south jersey so i am zone 6b-7a. I have two box fans that run Constantly. I have a screen door on one side and window on the other side. It usually gets up to 110F-112F topp in summer. I have no shade cloth on the roof and my tomatoes never have a problem with the direct sunlight or heat. I do have a sprinkler that comes on automatically( cools temp a bit) and a bathroom exhaust fan that I connected to a temperature controller to pull out the extra heat. I usually do tomatoes in summer because the fans will pollinate the flowers and the deer/rabbits won't eat the plants. Cucumbers did really well last year where they actually took over the entire greenhouse and I had cucumbers into November. They just have to be pollinated by hand. any question s let me know steve