I have a greenhouse which I only heat from mid-late March until the nights are warm enough not to need it. You could get a greenhouse (from a greenhouse supply place, not Farmtek) and use it like a high tunnel OR greenhouse depending on what the season is. In NH, I'd think you'd need some artificial heat to get peppers and tomatoes by late June, and feel fairly certain that a high tunnel without heat wouldn't do it, based on my similar zone and a grower about 30 miles from me that has a high tunnel for growing tomatoes. He may get some by early-mid July.
If you got an inflation buster, you could still put roll-up sides on it.
Griffin Greenhouse Supply (there is a location in Mass, and maybe in Maine) has a greenhouse that they call an inflation buster, and the price is less than things I've seen in Farmtek. It's worth checking out. For heat I use a "salamander" or "torpedo" heater, that I plug into a thermostat. It is a lot less money than a greenhouse heater.
Good luck.
Ann

Iloverroosters,
Hoophouses or high tunnels are the structures used most often for growers as season extension. Lynn Byczynski has a great little book: The Hoophouse Handbook available at www.growingformarket.com.

One of the greatest benefits of growing under cover early in the season is that crops harvested before the peak season bring in higher prices -- that means vine-ripe tomatoes in June.

You may also want to join the listserve I have linked below. Updates to the listserve are emailed directly to the email address you provide when you sign up. There has been alot of activity the last several weeks with some of the growers.

Here is a link that might be useful: Join List Serve on High Tunnel Information Sharing

Thanks for the listserve info Flowerfarmer.

I started with a high 20x96 high tunnel in 2001 growing tomatoes and cucumbers. It was a revelation for me although my season was ended when the plants cooked in my absense(at market) in Oct of that year. So I modified the structure by bringing in electric to include a thermostaticly controlled exhaust fan and intake louver, circulation fans, stoker coal stove and lights. Now I can plant in early March and have tomatoes in early June. It's now a greenhouse.

In 2004 I was able to purchase a used 30x96 structure and I immediately ran electric to it and installed an exhaust fan and lights. Other than a second exhaust fan given to me and an intake louver I bought at an auction, I probably will not install anything else in it. I typically don't plant in it until early April but it has convinced me to stop planting tomatoes in the field.

As far as definition goes the high tunnel would not have the electricity or heat features of a greenhouse. I've heard that some growers use that term to describe a portable structure to avoid paying higher property taxes. For me, I am not in such an area and the cheap improvements with mostly used supplies has doubled the extent of my harvest season with much improved fruit quality.

Both of these structures have the rollup sides becuuse the exhaust fans can't remove the summer heat near fast enough. I usually leave the sides in the rolled up position continuously from june thru Sept. anless bad weather threatens.

I've tried peppers with poor success mainly because of light availability when peppers are grown with vertically growing tomatoes(clipped to frame suspended stringline) and cucumbers( trained onto frame suspended plastic mesh). I might try peppers again in a future tunnel).

I have a small 15x40 bench greenhouse that I use for the potted plants- probably what you are looking for. You can erect one for under $1000 if you avoid all the frills. My frame cost $400 in 1994. I put a dubble poly plastic covering over it and haven't replaced it yet. It has a $3 used barn fan as an exhaust fan and a woodstove for heat. The benches are hand made stands covered with old doors and plywood covered with plastic. By April it is packed with plants, most of which we start in our house under lights.

Sorry for the rambling but I wanted to paint a picture of SEASON EXTENSION as it works for me. June tomatoes pay for my structure costs repeatedly each year. By mid july everybody has them.

Thanks Ann, flowerfarmer and bmoser for your replies. That is a big help! I will check out that greenhouse supply site to look at theirs. I think what I might do is start out with a bare bones greenhouse and put it where my chicken pen is now, since it is close enough to an electricity source that I can install heat and a fan.

I spoke with a gentleman at a recent farm expo, who said that he used high tunnels (cant recall if he had heat or not) but said the same thing about having the tomatoes in June being a great bonus for him! He's in the town next to mine and grows organically.

I wish you all great luck this season. PS are you all getting the crazy weather that we are up here in NH? 50's last week then 60mph winds and now arctic cold??

Just remember to close up the structure on windy days. An open ended greenhouse structure is like an umbrella in a wind storm. I've heard that most closed structures can withstand close to 100 mph winds. I hope none of us ever have to prove it.

To start out you could try to get by with a portable propane heater for the few nights in late April and May if you plant in mid-April. Check out the "Greenhouses and garden Structures" forum for other heat conservation ideas like double layering plastic or using an inner tunnel.