I would like to build a greenhouse on my property to start vegetable seedlings and herbs in to sell to the public. I would LOVE a big, beautiful glass greenhouse of course. I picture being able to have seating in the middle of it in the winter time and offering tea and snacks to sit and enjoy. I am in Massachusetts and HATE the winter! I look forward to this very much :) I know that glass greenhouses are probably the most expensive, but are they least energy effecient as well?

First issue is seems to be the norm. Its already too small. We have it packed with tropicals and there is a bit of room for a couple of chairs but thats it. Next spring we are going to add another 12 feet in length. Ill probably leave the south framed wall in place so we can temperature control the 2 zones seperately.

another issue we are noticing is how cold the floor is getting at night. The highest point of the hoop is about 7.5' and at head level its 65-70 and on the floor its around 40. We havent been running a fan to circulate the heat at night so Im trying that now to see if it helps. One thing I noticed is when the NG heater was not on the fan was blowing air across the cold plastic and circulating it also and too me seem to make it colder. Not sure how I can make the heater and fan come on together.

mike

The difficulties - the catalog said that a high tunnel / hoop house of my dimensions could be built by two people in four long days of hard work. It took more like two months with me squeezing in an hour or so of work early in the mornings before I went to work and a tiny bit after I got home (in the dark). When they say you simply screw this pipe to that pipe you need to step back and count how many screws they're talking about. Screwing tek screws up above your head while on top of a tall ladder gets real old, real fast.

My "greenhouse" has not made it through its first winter so I can't comment on how well it holds heat or sheds snow. In the past I built simple makeshift structures out of pvc and clear plastic and used electric or kerosene heaters and I managed to keep a lot of plants alive but I live in zone 7b and our winters are pretty mild.

I opted for wood frame to look nice and because for my purposes, it was easy. My biggest cost was about $1200 for labor. Materials for the building and furnishings was under $1000. The floor is covered with used carpet, so is pleasant to walk on summer or winter barefooted.

Right now, a fan is blowing heat from the greenhouse into my home. In the night, that process will be reversed. One small oil filled electric radiator provides the heat. It was 13 night before last and the GH did get down to 45 with this setup. The cucumber did not like that, but the peppers did and I saw no complaints from the tomatoes. Hope this gives you a little food for thought. THere is no harm in combining glass and plastic, so be flexible in your planning.

Hoophouses are not meant to take snow, though. In a big snow event, either you go out in the middle of the night and brush it off, or the weight will collapse your structure. Wind load is much easier to engineer around than snow load. If you get heavy snows and want the cover on year-round, you probably want an angled roof of rigid poly panels so that the snow slides off.

mike

Like the song, I loaded 16 tons (of gravel). But I actually got four days older and deeper in debt.

I really like reenforcing the end hoops with composite decking board.

finished!

And here's a pic of my current project. I'm hanging in there :)

Corrugated plastic might be the cheapest(and ugliest) rigid material and have an rf factor of 2. The more expensive polycarbonate and solexx can offer higher rf factors and longer warranty. All these materials can be purchased on rolls or sheets. Clear plastic is still by far the cheapest.

Avoid fixtures if you make a custom greenhouse. If I had the tools and money I'd be flaring 14 gauge pipe and bending it. If I had more money I'd go with Polycarbonate and a premade one. Check out Farmtek for ideas.

I have been buying my tomato and pepper seedlings from a local backyard grower who seems to be using simple plastic covered structures. This year I plan to start a few plants early to get a jump on the season. Indoors I have a wooden light stand using old hanging flourescent fixutes for seed starting. It worked out pretty well this year. I'm still in the learning stages but this gives me a warm indoor area for early starts.

Our vegetable garden is not close to the house and I was tired of hauling several lengths of garden hose for watering. The driveway is right next to the house so this meant running the hose across the driveway. Fortunately my husband is knowledgeable about things and actually found a used yard hydrant in our barn. We now have an underground waterline going to the cold house. It can be used during the winter since the water drops to below frost level in the ground. It required backhoe work to dig the trench.

The Coleman books give good charts on what vegetables are winter hardy. I am kicking myself that I don't have a better variety planted but will start seeding again once we get past the dormant months of short days. Right now I have a lot of spinach and beet greens. Possibly one semi frozen head of romaine lettuce. I still have spinach and carrots in the garden (as well as kale, turnips and parsnips). The ground hasn't frozen yet.

Since I'm still a first year beginner, I don't have a lot of advice but I think you can do what you want to do with a plastic covered high tunnel. Frankly, I don't think a tea party location is practical although yourself and a friend might find it pleasant.

I wish I had planted some of the hardier herbs in the cold house to see how they fare.

I think a combination of a high tunnel and indoor seed starting shelves will give you a good start in your business and not be terribly expensive. Best wishes.
http://s956.beta.photobucket.com/user/dfrost49/media/ghcropped.jpg.htm l?sort=3&o=1

Hudson - thank you for the snowy photo for my benefit. You are right, I love it!

Kitty - as you can see, everyone has different priorities, whether it's cost, productivity, aesthetics, convenience, etc. Only you will know what works for you. To answer one of your initial questions, yes, glass is a poor insulator in addition to being expensive and fragile. But if your heart is set on that, then perhaps you don't want to rule it out.

No matter what the type of structure, I do think that greenhouses offer a restorative and happy environment. I know I always get a boost in my spirits when I go in there and I find myself lingering longer than anticipated. I know that is a healthy thing, in addition to the healthy food we grow!

I am planning on glassing the top eventually but haven't found a design I like thats easy for the top and triangle top sides.

I like polycarb but like glass even more. Check craigslist for tempered glass and sometimes you can score.