Building high tunnel for cherries

I am planning next year cherry project and want to see what people think about building high tunnel. My Idea is to make 6X12 still pipe frame using canopy fittings with very low roof(less then 1’ at pike from horizontal). I was planning to use greenhouse film on the roof and fine netting on the walls for fly and birds protection, installed after bloom. Longer I think about it, more doubts I have. How would I hold greenhouse film in place? It will be most likely pretty strong sailing effect, so plastic clips will just snap off. I can tie film corners to the pipes, but 12’ looks too long without a tie. Should I start considering some other options for roof? Is it better for the cherry to have it removable for winter to let snow cover the soil (I am in zone 5) or should it be permanent? I am open for suggestions!

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I’ve often thought, if I had it to do all over again, to plant fruit trees inside a screen house - all screen, no film.

Google “Greg Lang at MSU” he is probably the leader in research on cherry production in high tunnels. You can find tons of YouTube videos and articles. I was a lot more versed on the do’s and dont’s a couple of years ago when I had high hopes of getting a high tunnel in place. That project is now on the back burner for a few years, but someday I hope!

From what you’ve stated your goal appears to be protection of the fruit near harvest from rain and critters. So I’d think you only want it covered for about a month ending when harvest finishes. A flat roof of greenhouse poly in winter would require a very strong frame to carry snow load. That would serve no purpose.

Attach with wiggle wire or something similar http://www.greenhousemegastore.com/product/spring-lock-top-section/polyethylene-film-install-accessories. I attach poly to my sunroom Oct to March using a similar system.

@ltilton, I hear you… I am moving to that site by site… Most of my veggies are in screen house… And I started with trees as well. But one huge screen house - yes, it’s a dream!

@TurkeyCreekTrees, I did google… The problem is all the video are for production sites, with huge tunnels. Mine is small and for backyard. But thanks for suggestion.

@fruitnut, I also thought that protection from rain should reduce canker pressure or it’s not? If not and I only need protection for cracking, it is different story then.

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Some considerations:
Wind direction.
Will the structure be partially shielded from wind by other structures.
Both the rain and the insect protection are temporary, and so no need to protect from rain year round, thus design for wind pressures in other seasons.
All rain is not bad - just days and days of inches and inches.
The insect protection is not so much affected by wind as the poly will be, so…
If you are using poly to protect from rain, the whole structure need not be covered. This reduces wind load and allows some air circulation.
When I design these kinds of things I try to do an ad hoc version 1.0 with on hand materials as soon as practical to flush out design considerations I hadn’t thought of. This saves time and money.
No need to explain which ideas help - just throwing ideas out there.

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Yep)

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A partial roof might provide some canker protection. If that’s the case leave the roof on May thru September.

Unless one goal is protection from winter cold you don’t want anything over the tree in winter that might build up snow and ice. Winter protection probably isn’t a goal so that top covering must be removable.

Thanks! I think I got an idea how to make it removable.

I don’t think you’ll find anything more secure or easier than the wiggle wire. And get the 4 yr UV stabalized greenhouse poly http://www.greenhousemegastore.com/product/thermal-ac-greenhouse-film/6-mil-polyethylene-film

The cheaper poly that’s not UV protected will only last a couple of months.

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They sell temporary carport kits that have aluminum frames and white tarps. Perhaps look on Craigslist or other online buy sell sites to see if someone local has the Al frame to give away or sell dirt cheap after the tarp covering has on out. You could screw down the Al frame work to some pressure treated 2x6 lumber and attach your own poly over the roof frame and screens along the sides and ends. Maybe add gromets along the edges and zap strap them in place. Simply cut zap straps to remove at the end of season. Just a thought. I used one over my deck and the frame stood up well but white tarp was toast after 2 seasons.

Anthony

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Yes, I mean to get the right film(http://www.greenhousemegastore.com/product/solar-max-reinforced-poly-film/plastic-film), but wiggle wire requires special metal piece to install it into, at least this is how I see it on the pictures. My idea should be much simple and cheaper for me - I will have a large piece of plastic big enough to cover whole roof. I will roll two opposite long sides of the plastic on two thin pipes and fix it there with wire. The pipes will be longer then plastic so I can tie the ends to the ground . Here is a simple 5 min prototype.

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I noticed that film you recommended has 91% light transmission, and the one I picked is 85%. In your opinion, is difference significant? I picked it for it’s durability and also custom size. I had no much luck with cutting large pieces of plastic. Tried it before and failed miserably… I simply have no empty spot in my yard big enough where I can lay down 12X25 piece to fold it right way and cut…

I prefer the type that diffuses light. It gives a better light profile in the tree canopy. But 85% isn’t really much different than 91. Not enough to make a difference. The type you linked to is good stuff and appears to diffuse the light.

I don’t really know how you will securely attach the poly to metal pipes using wire. But it’s your structure.

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I did it multiple times before. You fold the edge several times to make it thicker, then staple leaving the tunnel just enough to pass the pipe through, like on the prototype. Then if staples are not secure enough, you can punch holes through folded plastic and use wire to make secure loop around pipe. Pipe still will be able to move inside the plastic, but it is OK, as ends of the pipes will be tied and plastic will not have a way to slip.

I started a similar effort 2 years ago with the planting of about a dozen gisela based trees in a row with the intention of building a tunnel over them when they came into bearing but my considerations were this:

  1. Erect and take down every year so that i don,t have to look at and maintain a structure year round.
  2. Bird prevention
  3. Control of water during ripening.

My thought is that #1 and 2 could be accomplished with a lightweight structure of hoops that would allow bird netting to be easily pulled over it. But if i try to solve #3 with a canopy there goes my lightweight structure do to wind pressures. So can #3 be accomplished at ground level with a water barrier of some kind that drains to a gutter? Is it correct to assume that water falling on leaves and fruit is not the problem, it ls excess uptake from roots.

So that is the approach i am taking. Somebody must have already thought of this or tried it and realized its a dumb idea but …it’s the current plan…

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Actually, both - water on berries and water on roots play role. You can read it here::
Single-layer plastic covers provide excellent protection from fruit cracking caused by rain directly on the fruit. However, as noted in the May issue, cracking also can be caused by excessive soil water uptake, and we have documented fruit cracking as high as 60% from rainwater that flowed off the tunnels into soil near the root system of covered trees (this rain event caused 90% cracking in uncovered trees).

I am thinking about installing some protection for roots. Also my trees will be planted on the raised bed, and end of plastic will be outside of this bed, that may help too. For the permanent structure - I have so many of them in my yard, so I do not care anymore. I am at the point when installing a new frame every spring will be unrealistic for me, as spring is also very busy time with vegetable garden I have.

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Good info. A little bit surprising that the rainfall on fruit and leaves by itself has an influence. Here is a link to Lang’s previous article that he references on why cracking occurs.

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@galinas sorry, I know this thread is from 2017 but I have been considering a similar structure. Did you end up building this for your cherry project and how has it gone?

I did, but it didn’t work well. First, I received the plants as probably 2 years old, if not three. They had pretty thick trunks and building UFO structure from them was very difficult and trees tried to get to regular upright position by providing new trunks and didn’t produce. Second, the netting prevents lady bugs from getting in, so the black aphids had their fest inside. I never got to the point to test plastic cover - just didn’t have enough cherries to bother. Now we sold the house, so it is not my problem anymore. I am not planting sweet cherries at my new place.

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