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My Experience with Haygrove high tunnels

Steve Groff

I put up a 1 acre Haygrove high tunnel 2 years ago. It has 6- 24 feet wide bays that are each 300 feet long. I had several reasons for being interested in a Haygrove high tunnel especially after I had experienced 8 seasons with a small 15 X 96 foot high tunnel. Basically I was looking for all the benefits (earliness, quality, and increased yields) a high tunnel gives but on a much larger scale. I found out that there is a learning curve in going to a larger structure.

Plant Density

I planted 6000 plants per acre the first year to maximize the use of the tunnel. The result was 6 foot high Mt Spring tomatoes that were too leggy. This past season I reduced the plant population to 4800 plants per acre and was satisfied with the overall result.

Ground cover and raised beds

The first year I planted into the bare soil. I had lots of weeds even with herbicides applied. I spent about $2500 on ground cover and installed raised beds the second season. That was a huge step forward as we had very few weeds and the soil temperature warmed up quicker.

Irrigation and fertility

When my plants were growing so high the first year I reacted by lowering water and N rates. This helped retard the growth but then resulted in small tomatoes for the last half of the season. This past year I was able to control the excessive growth and legginess with weekly N application and venting on windy days. The size did drop off toward the end of the season and that is a challenge I will try to overcome next year.

Season extension

This past year I planted the 3rd week of April and harvested from the first week of July until the first week of November. I hope to use row covers inside the tunnel in the future to add more production on either end of the season.

Yields

In 2003 I had a total yield of 2,400 25lb boxes of #1’s and #2’s. In 2004 the yield increased to 3,400 boxes. 2004 was a very wet year for us and for a comparison, our field grown tomatoes of the same variety produced only 1,200 boxes per acre.

Quality

Overall quality is impressive, especially since both years were not good growing years for field grown tomatoes. A rough estimate would be that overall we had about 70% of harvested fruit grade out as #1’s.

Disease

I have found disease pressure to be about the same as a small high tunnel-noticeable reduced. I do spray fungicides when deemed necessary. I use my field air-blast sprayer and sprayed in from both ends. It seems to provide adequate coverage and considering the option of spraying it by hand, it seems to work well.

Cost of structure

With the ground cover, labor for assembly, and initial cost of the structure I figure I have about $30,000 into it. On a square foot basis, this is about ½ of what a small high tunnel costs to build.

It took us 250 man-hours to build, but I believe I could do it again in about 200 hours. Ralph Cramer, the eastern US Haygrove representative, was very helpful in giving advice and instruction.

Maintenance

Putting on the plastic in the spring is a huge job. 6 people can do it on a calm day, but 8 or 10 are better, especially if it gets a bit breezy. The key is to be ready when the wind is calm and to do as much as possible at that time. Plastic covering and installing end doors takes about 50 man-hours.

After the plants are planted it is important to properly vent the tunnel to provide optimal growing conditions. This is a learned art by experience. You have to make venting decisions based on temperature, wind speed and direction, and stage of the crop. During fruit set, the most critical time, I look at the hourly weather on the internet every day for wind speed and direction. During that 6 week period you need to almost literally baby-sit the tunnel. Around June 1 or so the tunnel remains open the rest of the year and the end doors come off. If at anytime while the tunnel is fully or partially closed you must fully vent the tunnel if high winds are expected from a storm.

After the crop is finished the plastic is removed and placed in the gutter of every other bay. This takes about 20 man-hours to complete.

Marketing

High tunnel tomatoes are of better quality and should be sold for a premium price. I have gotten good prices at both ends of the season but am still looking for a better price during the middle part of the season.

Next year…

I am going to replace my plastic with the new luminance plastic that defuses light and has shown increased yields in other crops. I will use the old plastic to create interior walls on the leg rows as a way to keep the tunnel warmer on windy days in the spring. I will also continue to pursue optimal fertility and irrigation strategies.