I'm Ron Patterson with Utah State University Extension in Carbon County.
These high tunnels will hold the heat when it gets sunny; it'll get hot - very
hot - inside the high tunnel so we need to have some ventilation. There are
different stages of ventilation; if it's a cold but sunny day outside you still
need to have the ability for the heat to escape, otherwise you'll cook your plants.
The first stage of ventilation would be to open up this vent on the doors - I have
strings - I actually prefer to let these drop all the way down so, but the hinges
aren't set right on these, but anyway that will allow that heat that's
building up inside the high tunnel to come out but not get too cold; the
heat of the sun is going to keep building up. Now if it's a cloudy and cold day you
might be able to leave these closed, but around here the sun comes out and
then cloud and it's only usually partially cloudy during the - during the
cold months. And so I will even on a semi cloudy day will leave these
open during the day, and then of course you shut them at night so that you don't
get the cold air coming in. But if it's a semi cloudy day then I open these up, if
it's a sunny day I open these up, if it's not a cold day, so that's stage one of
ventilation - of heat ventilation. Stage two: you could - you could open the
side curtain; with these open and that's a little bit...will draw a little bit more
air. Or you can open up the doors on the ends of the high tunnel...I have a latch
back here that I have to keep the door holding open, and that will allow quite a
bit more. So if it's a sunny and cool day, like 25 to 35 degrees, you might want
to open these doors...no, not on 25 to 35 degrees. If it's a cool day like your low
30s, then you went on to open the doors during the day - especially on a sunny day.
A cold day will be below freezing; you don't want to open the doors when it's -
when it's freezing outside, but you
you want to have some ventilation to keep things going.
The other thing then, this is kind of stage two then, and then you can lift up the
side curtains as we go. So stage three would be to lift up the side curtains, and you can
lift up part of it or the whole thing on one side, so I'll show you how that we
how we do that - lifting up the side curtains. And then the full ventilation
would be opening up the side curtains on both sides, so I'll show how I do the
side curtains for partial ventilation and then for full ventilation. So the
keeper strap for the the side curtain is basically - I just use a piece of twine
and a 1inch S hook that I've pinched this side here, the one end shut - and that
hooks into the eye screw that we've got attached outside. Gets tied to the rib on
the inside, and then it'll hook in there so that keeps it in place and it's
worked really well. While we're talking about ventilation we need to talk also
about wind direction. I had an incident with the wind this spring; this is the first
time I've had this bad of a situation with this particular high tunnel. I have
had the - usually the winds from this area come from the northwest or the southwest -
well this year they've kind of been coming from the east. They haven't been
really strong but I did lift up and use the - usually I'll do my first stages of
ventilation lifting on the east side - we had some sort of a microburst, or twister,
or something come through here. And it blasted through this east side and
because I've got the west side closed it hit the end wall, actually kind of tore
apart my end wall. So I didn't have time at that time to get it filmed; I was in a
hurry, had some family things, and then trying to keep the plants protected, but
I've had to reconstruct the end wall. This is the least amount of damage I've
had done with a windstorm like that; I've had whole high tunnels blasted apart
before, but this one has withstood at least th- strong winds. Also the
neighbors have got a dog house over there with big rocks on plywood. It
lifted the plywood off from the - the doghouse, and it stripped up strips
of drip tape that's semi buried - it was kind of half buried and half not buried -
and it's stripped it right up out of the ground then lay that straight across the
neighbor's yard to the north. So it was a pretty powerful wind that came through,
so I'm - I'm pleased that I didn't sustain more damage. A little bit discouraging
when it happened, but you need to be paying attention to wind direction when
you do your ventilation. If the wind's coming from - if you're strong winds
are very consistent - coming from the east or the west, north, south, whatever, that's
the side that you want to leave down. On the windward side so that you don't get
that ballooning effect of the wind coming in, pushing things up, and trying to
escape out the end of the high tunnel. So I would be remiss if I didn't talk a
little bit about the capricious nature of the wind around here on - in our
area, so...so pay attention to the wind direction when you do your ventilation.
So what this wind did is it busted out that end, well you can see that that's
not in place, and it snapped several of these twines, and it actually lifted two
of these T posts - one on the end wall and one here on the corner - lifted them clear
up out on the ground. They'd been fastened down in the ground, set solid, and
that wind just just pulled them right up out of the ground - it busted apart the
end wall, so I had to reconstruct it. But it pulled up my stakes, or it snapped the
line, and then you can see with all the exposed ends of T posts and everything,
it kind of tore the plastic. Now for the most part I can kind of patch this up, or
pull it together and it should be fine; the little holes are pretty easy to
patch, these bigger holes I'll have to come up with a way to kind of keep them covered.
But you just have to be careful when you're when you're ventilating...well,
sometimes you can't plan for everything so...it happens, and you just keep
going on. This - it's held up quite well, but another thing to think about
when you're doing your ventilation. Here we have the high tunnel finished; I've got my
trellises put up, and plants planted, I'm ready to have some fun in my high tunnel
in my garden.