Greetings all- Happy New Year.
Has anyone within our group yet had any success with growing fruit trees within high tunnels?
After some extensive research and talking with Dr. Bill Shane with MSU and Jon Clements with UMASS (among others), it appears there have been growers who have employed high tunnels to good effect, particularly with sweet cherries.
The most prevalent advice I have received to-date has centered around three considerations:
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Higher sidewall height- i.e. utilize 6’ high sidewalls in lieu of 4’.
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Use of a woven greenhouse cloth (similar to Solarig) for the roof in lieu of clear poly.
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Maximize passive ventilation possibilities within both the side and end walls (and roof if possible).
Ultimately, it appears that when employed correctly high tunnels can at least be utilized to mitigate the threat of early-season bloom damage and rain-induced cracking.
Have any of you all had any experiences/lessons learned that you would be willing to share?
Thank you for your help!
Russ
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This is going to be a year for trying a few new things with my small high tunnel,if seven feet maximum height is called one.
The past couple of years,I’ve only opened the ends,by drawing back one like a curtain and the other has a door,plus two auto vents on the North side.
This time,the whole South side will be able to get rolled up(poly)if the internal temperature gets too high,along with the open ends.Shade cloth was used before,over the plastic,but sometimes wasn’t enough,on hot,sunny days.Incorporated also,will be bird netting,which can be used when the plastic is drawn up.
These three things will give me a better control of temperature and easier access from the outside for watering and pest control(Aphids and Spider mites).
I’m growing mostly Plums,Pluots.Nectarines and Peaches.The covering definitely stops Peach Leaf Curl,but can present problems at times with mostly insects. Brady
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In my experience, commercial high tunnel height matches the upper limit of height of the workers. As such, the peak height in the SW tends to be 6’ while in temperate Alaska (Palmer – Homer) it’s more often 8’.
Enclosing your trees/plants will change the growing dynamics by several variables. Fine tuning it to a particular location is about the same amount of effort as dealing with the uncovered conditions – albeit “what you can grow” may be different.
I wish you lots of success in this effort. 
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I’m not sure I’ll actually ever do this but I’d love to build a permanent greenhouse & try growing lemons, limes, figs and avocados.
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I’m been pondering this as well but our deep snow would require constant attention to keep it from collapsing from the sides, not to mention the cost of buying and heating the greenhouse. if you were closer, id go in on it with you. haven’t found anyone up here willing to commit. the university nearby has a greenhouse and i could go to them for info on how to set up. they grow in there year round.
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Hey Russ:
I think you can be successful in MI with cherries and similar fruit tree crops. The high tunnel/greenhouse needs to be designed around the crops, climate, and objectives. If you just want to do what MSU is doing you could grow peaches, nectarine, plums, and other stone fruits with a setup similar to theirs. If you want a longer growing season or to grow other crops like figs, citrus, or tropicals then you would do well to design a different setup.
Can you give us some idea of what you want to do and what crops you want to target?
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Thank you all for your help and input.
Our goal is to plant early-blooming stone fruits (i.e. apricots, sweet cherries and Asian plums) in the tunnel to help mitigate against early bloom injury and rain-induced cracking.
Here in Western Kentucky, we get frequent early February warm-ups followed-by a significant cold snap which spells doom for those short-season trees that wake-up early.
In Kentucky, the NRCS is trying to promote the use of high tunnels such that they are willing to significantly subsidize the effort- thus my interest in exploring ther use in an attempt to grow fruit (i.e. apricots) which typically are not successful here.
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That should be doable in W KY. I’m not convinced that a covered tunnel by itself without heat will save the crop from spring freezes. But if it will then MSU should be able to verify that.
My thinking goes first to when do I want the covering in place and when not. Obviously you’d want it covered once bloom starts. That would be in Mar/April in KY. But do I want to force bloom early by covering in say Febr. And how long into the season do I keep it covered. How much effort do I put into water control. Water is the key to better fruit quality.
You need to think thru all that and more because it affects the design.
A taller structure is better for heat control because it raises the zone of hottest air. But taller is much weaker in wind or if you get a late snow. Ice and snow can be a real factor. So the structure should be uncovered in winter unless designed for the load.
A 50% light level is plenty under the woven poly. That’s what I have and it works great. Mine in fact is covered with two layers of woven that’s inflated.
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I agree, heating can be hard to do. We heat our 16X24 with a radiator set up that is branched off from the wood boiler for the house. My father had a geodesic dome greenhouse ( I have that now too) and he heated it with a small wood stove used for ice fishing huts. Not good for year round, but definitely extends the season in spring and fall.
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my father used to have a trailer furnace rigged on a thermostat in his. he started growing i march and went till’ late nov. he had tomato trees and 15ft. cucumber vines in there! was like walking into a thick jungle!
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Good feedback- my thought (possibly oversimplified) is to choose cultivars that are latest blooming within their respective group and then allow the earliest blooming tree under the tunnel choose when the roof goes up and the sides come down each year. At that point, minimal supplemental heat is supplied to protect against frost and if the heat accelerates the bloom of other trees under the tunnel, so be it.
Then, once the threat of frost is passed (early/mid March for me) the sides and the ends are rolled-up and the high tunnel strictly serves as a rain screen.
Obviously, this does not address irrigation nor disease/pest issues which.must also be taken into account.
In addition to water and temp control, a high tunnel could provide some disease protection. I read (trying to recall where) about one farmer who put filters on his GH and particle filters on the air intake. This greatly reduced/eliminated his disease problem (blight on tomatoes as I vaguely recall), as the filters kept the disease spores out.
May not be worth the trouble and expense, but something to consider for airborne disease.
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Keeping the rain off the trees protects against many diseases of the fruit and tree. That assumes the structure isn’t kept highly humid for long periods. It can also protect against losses to vermin, wind, hail, and even things like larger insects if screened. I have almost no losses in mine. The trade offs are mostly more spider mite issues.
At MSU just having poly over the trees pretty much excludes Jap beetles. They navigate by UV light and the tunnel is a dark hole to them. So there will be some positives and negatives that might not be obvious.
You are on the right path in terms of when to cover. You’ll learn a lot the first yr. Consider doing like Brady and screening out birds and other vermin. They can take a lot or all of the cherries.
I’d chose the best tasting cultivars and run a heater as needed.
Water will be a big issue. Consider having rain gutters and run that water into a storage tank for irrigation or run it out of the root zone. Cherries can crack just from water uptake by the roots. Plus I’ve had 25-30 brix the last few yrs on many stone fruits by restricting water.
Gentlemen: Thank you for your excellent feedback. Great considerations.
While coordinating with high tunnel manufacturers, I have been asking them to include gutters and downspouts - and I have been evaluating a micro-irrigation application, possibly with rain barrels.
Thank you all very much for your help and experienced feedback.
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Contact the N.R C S about the high tunnel cost share program.
Best deal ever !
See tonyomahaz5 "repost from a fig forum for free greenhouse "
On this site.
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I have a high tunnel,with a mix of citrangequats , fig, pomegranate ,blackberry ,strawberry , assorted vegetables ,etc.
Going on the 3rd year., unheated.
For the vegetables ,in the winter you want to catch the Suns warmth , to keep them growing.
BUT ,for the perennials ( fig, pomegranate , etc.) in the winter you want to keep it cool, so as to keep them dormant.
Iam in West Virginia , the H.T. Does offer a lot of protection.but it still gets cold in there.
The worst is that cold nights are often preceded by sunny days. Without proper venting on those sunny days, it can warm up a lot in there ,breaking dormancy, followed by a very cold night !!! And freeze damage.
The NRCS program requires no supplemental heat ,for the first 2yrs.
I think a heat source ,to at least keep it above freezing at times ,would be good if you are trying to grow perennials in there.
I am planning to add heat next year in mine.
Does not have to be warm, just above freezing , at critical times. , when the plants have come out of dormancy, bloom, etc.
Humidity is an issue,when it is sealed up.
Mine has 6’ roll up sides, and 4… 4x4 ’ vents up high on the gables.this allows very good ventilation in the summer, and good humidity control in winter . Without a fan.
Anti drip Polly film may be a good choice , mine is not and I get a lot of drips.
Gothic style" with trusses "seem to be stronger, and shed snow better than quansett
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As mine is only 3 yrs old I don’t have a good long term report on the success of trees in there.
The amount of food, (mostly vegetables so far ,) that comes out of there is truly amazing,
I highly recommend getting a HT.
There is a " big" learning curve , to growing in a HT.
I am a good gardener outside.But I am having to relearn everything in the HT.
Things are different in there, problems you had outside may not be in there.
And then there are issues in there that never were outside
Everything is different .
It’s like learning how to do it all over again
A HT. Can be the most versatile building on the farm.
A good place to garden on rainy days
Critter control.
A sanctuary .
Good work space ( fix truck , lawn mower, messy projects )
Storage of garden equipment etc.
Season extension .
Zone extension .
A heat sorce.( could be attached to house)
And all that food
So check out the NRCS high tunnel program.
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Hillbillyhort:
Thank you for your excellent feedback relative to your current high-tunnel operation. It sounds as though you have learned some helpful tips along the way, and I sincerely appreciate you sharing.
Much of the excellent feedback I initially received was from the USDA Research Station in Kearneysville- those guys are very helpful!
Thank you to all for the great input- it is most appreciated!
