While I was visiting Hank Letarte at White Gates Farm, Hank asked me if I wanted to go see Ledgewood Farm, which was only 20 minutes away. I had always intended to stop by there, but never got the chance. This was just too convenient. Hank even drove. Thanks, Hank!
The scoop on Ledgewood, quoted from their website: Ed Person owns and operates Ledgewood Farm a 22 acre retail vegetable operation in central New Hampshire. The farm also manufactures greenhouses and high tunnels for the commercial market. The farm has been in his family since 1947 and he has manufactured greenhouses since 1987. The business operates with one year round employee and eight seasonal employees. http://www.ledgewoodfarm.com/
Ed was out. While there, I met Rob, who is with him full time and does on-site set up of the high tunnels for farmers chosing that option. After checking out the shop, he graciously gave us a tour. Thanks, Rob!
This was a great visit and an unexpected bonus for me. Awesome.
On 12/6/10, we met with Hank Letarte, a farmer/entrepreneur in Tamworth, NH. A renaissance man of sorts, Hank has been an engineer, power plant operator, landscaper, cattle farmer, and now a biodiesel manufacturer. He teaches classes on animal processing and lead safety, among others. With the help of the NRCS , he recently added two Ledgewood high tunnels to his property. He now sells vegetables, beef, poultry, and pork at his farm and a local farmers' market. There's more info in this blog entry on Hank and White Gates Farm:
Farm Visit - White Gates Farm 3.30.11 He has a sand pit on his property and when the local tree service needed a place to dump wood chips, he decided to take them.
Noticing that they were composting and creating heat, he got an idea – why not harness that heat and use it to grow winter vegetables? He created a windrow 40 ft long by 8 ft wide on top. He then added six inches of loam on top. His thought was some type of hooped structure or tunnel on top to retain the heat. At that point, he enlisted our help. This is how it looked when we arrived.
This thermometer, inserted just beneath the loam, read out at about 60 degrees F. When fully inserted into the middle of the pile, it settled around 140 degrees F! We were both impressed and intrigued. I decided that the best structure for this would be six ft wide Quick Hoops low tunnels, because the wood chips could support them. We offered to help him with materials and as the conversation progressed, it was evident that he would need more than just materials, so we offered to help him set it up and plant. We went back to the farmhouse and laid out some rough plans.
Thinking that a certain size heap (or cross-sectional area in this case) would be needed in order for the chips to reach ‘critical mass’ for adequate composting, we asked him to create a second windrow, about half the height as the first, to see if it would generate the same heat. In other words, how deep do they need to be for this to work?
Threading the needle between winter storms, Adam and Andrew Mefferd went back on 12/9/10 to plant and set up. It never got above 12F in the pit that day. We knew the loam wouldn't have sufficient nutrients to sustain the trial, so we had a 2 yard sling bag of Compost Plus delivered from Vermont Compost. Unfortunately, the compost was frozen solid 3-4 inches in from the outside. Sowe had to hollow it out like a big pumpkin.
We spread a 2-3” layer of compost on top of the loam, which itself was also frozen solid and attempted to work it in with the Tilther. This worked in some spots and the Tilther just bounced around in others. So, for the most part, this was going to be just a heavy top-dressing.
After tilling and raking, we used the bed prep rake with tubes attached to the tines to mark three rows.
Then, we planted:
Tytan Parsley
Vit Mache
Mei Quing Pac Choi Red Ace Beet
Elegance Brassica Mix
5-Star Lettuce Mix
Hakurei Turnips
Rover Radish
Bright Lights Swiss Chard
Along with the seeds we brought, Hank also had three trays of lettuce seedlings for us to plant.
Erecting the hoops. We drove t-bars in the ends as deeply as we could and used hand pegs to secure the Agribon and plastic.
Both windrows had mirrored plantings for easy comparison. Hank was also going to add sand along the sides to make the tunnels extra secure.
On January 20th, 2011, our QA manager, Bonita Nicolas and I stopped on our way to the NOFA NY Winter Conference, to check on the trial and install some temperature loggers.
There already were signs of life in the big tunnel.
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On January 24th, we stopped in the pit at 9:00 at night and picked up the loggers.
On March 30th, I returned again to check on the trial.
Hank, removing the cover.
In the tunnel on the big windrow:
In the tunnel on the smaller windrow:
Summary and conclusion: There's really no new product as such that we were trying to develop here, just investigating the feasibility of a different method for season extension. The heaps definitely produced heat. The fact that anything was growing in January (after being planted in December) is pretty impressive in and of itself. However, the trial definitely had its challenges. The cover blew off several times, the thin layer of potting soil we added only had just so much nutrition to offer, the soil was quite dry when inspected in March having never been watered, and we were trying to grow vegetables during a period know as the 'dead zone' with very short day length. What I can conclude is that the heaps definitely produced heat, and the bigger one produced more than the shorter one. We saw anywhere from a 10 to 34 degree temperature differential between the inside and outside air. It also had better results than the shorter bed in the way of overall plant germination and growth, so the added heat promoted earlier growth. As for feasibility, I'm not quite sure. Hank plans to do more with hot beds, but that is just in the planning stages right now.
Max
Min
Average
34.2
9.6
21.3
This was a fun project and Hank was great to work with. The entire gallery can be viewed here:
On 3/30/11, I visited Hank Letarte, a farmer/entrepreneur in Tamworth, NH to follow up on a trial we were doing there. A renaissance man of sorts, Hank has been an engineer, power plant operator, landscaper, cattle farmer, and now a biodiesel manufacturer. He teaches classes on animal processing and lead safety, among others. With the help of the NRCS , he recently added two Ledgewood high tunnels to his property. White Gates Farm is an interactive farm in Tamworth, NH. They raise grass fed beef, pasture raised chickens, pork, and produce. They also produce organic compost, maple syrup and biodiesel fuel and they welcome farm visits any time. Here is a brief gallery of photos I took while there, plus a few from their facebook page:
While we were in Winterport, Chris Hillier and I decided to see if we could stop in at Fisher Farm. http://www.fisherfarmcsa.com/
Their farm stand, which was being renovated had a prominently displayed poster size copy of one of our catalog covers, featuring a shot of their display at the Common Ground Country Fair.
Chris' notes sum it all up very well:
We didn’t have a scheduled tour at Fisher farm, but we decided to stop by anyway. Beth Haines' in-laws were there, so Rose Fisher showed us around. They have two greenhouses set up with seedlings started. They have chickens and sheep near their tool barn. Their 30x96 hoop-house was stocked full of chard, beets, tatsoi, arugula, kale and other greens. Most was ready to harvest. They also had thrown in a row of overwintered onions. They have a 50 family CSA and go to a few farmers markets. They have diversified vegetables and eggs and cut flowers. There wasn’t much happening today, but you can tell it’s a bustling place to be during the growing season. Beth and her husband live in an “off the grid” house with solar panels, water pumps outdoors next to the outhouse. Quaint and rustic – a beautiful farm.
Three farms today - all had chickens. I'm seeing a trend here. :)
Chris Hillier and I also visited the farm of Paul and Christine Lipsky in Newburgh, ME last Thursday. They have been to our twilight walks at the research farm many times and since we were in town, we thought it would be great to see them and their farm. http://www.mofga.net/MyProfile/tabid/88/asuid/1488/showtab/products/Default.aspx
They use Quick Hoops extensively on their farm that is literally carved out of the woods. Paul showed us around their property. He said that he removes snow from his low tunnels, so he doesn't really have to worry about collapse. He said he was challenged by voles though. For this, he had homemade boxes with Intruder mouse traps in them as recommended by the Winter Harvest Handbook by Eliot Coleman.
These are Chris' notes from the trip:
Paul and Christine also have a backyard farm in Newburgh, ME. They had three garden plots plus a chicken house/plot. Two of the three gardens had quick hoops set up with overwintered onions (Bridger), spinach and Encore Salad mix. They also had some hoops set up to keep the ground warmer to plant early broccoli. That is one crop they have identified in their market that many will pay a lot for getting early to market with it. They are also looking to build some more soil up to put in some moveable hoop-houses. He probably has ½ acre tilled up. They sell at two farmers markets, Orono Buying Club, and two natural food stores.
Mark runs a commercial operation and CSA on just 1.75 acres with 3/4 of an acre in production.
I had spoken with Mark at the MOFGA Spring Growth Conference last Saturday and he told me that he had structural failure in his Quick Hoops. This was the first actual failure I had heard of, so I wanted to investigate what went wrong. Eliot Coleman's concept for the Quick Hoops Bender a few years ago was born out of the need for hoops that wouldn't bend under snow load like PVC hoops do. In our trials at the farm last winter, the 1/2" EMT hoops held up extremely well, but when the soil moistened up in spring, the hoops tended to lean and cut through the soil without bending.
This was the case at Mark Allen's farm, only worse. Due to the very wet conditions caused by drainage challenges at his farm, the hoops under snow load leaned over, then started to widen out as the bottoms of the hoops poked through the soil. Now much wider and with greatly reduced strength, the hoops then caved in. Also, once one hoop moved, the entire length of plastic was now loose and able to catch much more snow. The result was a domino effect. Mark had tied off some of his end wall hoops to the end stake, but since the hoop ends cut through soil, they were of little help.
Mark stated that he intends to do some work to aid in soil drainage. My recommendation for him for next season is to run a rope purlin the entire length of his tunnels, tying off to each hoop individually and to stakes on either end. I also suggested he use beefier stakes like T-posts driven deeply, as they will need to bear the weight of the entire tunnel's snow load. Hopefully, this will work for him.
After analyzing his low tunnels, he gave us a tour. Eliot Coleman's influence can be seen in many of the methods employed on his farm, including soil blocking, wire wickets, and the use of Quick Hoops.
Goal: To see if either caterpillar tunnel version (with, or without purlins) could withstand winter snowload.
Results: Were very interesting. We picked two of the four tunnels that were built in May, 2010, actually planted onions in them, and buttoned them up for the winter. Both tunnels were structurally the same, with a center ridge-pole made of chain link fence top-rail, but one of them also had purlins about three feet from either side of the ridge. These purlins in summer, were used to trellis vine crops, and carried that load quite well. They really stiffened up the whole structure. However, in summer, they tended to cause the plastic to collect rainwater. This made me think that the purlins would either make it so strong that it would better carry the snow load or they would catch more snow than the tunnel without purlins and cause a collapse. It looks like the latter is the case.
Summary and recommendations: It is important to note that we intentionally did not remove snow in this trial, as we were looking for structural failure in worst case conditions. Removal of snow even just next to the tunnel that failed probably would have prevented its failure, because the pressure bearing in on the sides (and therefore the plastic's weight felt on the top) would have been greatly reduced. If you intend to use a structure like this to overwinter crops in northern climates where snowfall is a concern, I would recommend a maximum of four foot bow spacing during construction, not using side purlins in winter tunnels because they catch snow, and of course the removal of snow whenever possible from the sides and top of the tunnel. It would also be prudent to shore up the bows internally with notched two-by-fours placed vertically under every other bow as a means of additional snowload insurance and peace of mind. The 26-page illustrated manual for the bender used to make these tunnels and an MS Excel cost calculator spreadsheet may be downloaded on the bender's product page here.
