How to Build a High-Tunnel Greenhouse _ Ask This Old House

I just planted it .

What do you think ?

Well , I love that you did a raised garden because that allows us to control the soil that's in there .

So we can have good soil for the vegetables .

I know the native soil here in Mississippi is not so good for growing vegetables .

It's not , well , with a raised bed , we've eliminated that problem and it's nice because you've put in this basil , some lettuce , some collard greens .

Great .

Now , as garden , as we can control some things , we can control the soil , we control how much water they get .

But one thing we can't control is frost and these are tender annuals .

If they get a good frost , they'll all die .

What if I told you there was a way you could grow vegetables all winter long .

That would be great .

Well , this is what we're gonna do .

We're gonna put a high tunnel , which is essentially a greenhouse that's unheated over this bed .

That's great .

Well , we gotta get some supplies so we can build it .

Let's go .

Ok .

We're gonna use PV C to build the roof of a high tunnel .

Now , we're gonna use a 20 ft length because it'll bend easily and be strong .

Ok .

Now , here's the one inch pipe in diameter 20 ft long .

This one right here , you got it .

You got it .

All right .

Let's head out and get the lumber we need .

All right , we need some pressure treated two by fours to support our pipe and build our walls out of .

We're gonna need 4 , 10 footers and 4 , 12 footers .

Ok .

Sounds good .

We're gonna cover everything with four mil plastic .

So if you just grab a roll up here , I think that's good .

We're ready to go to work .

Our high tunnel is gonna be 10 ft by 12 ft and that'll allow you to put in another raised bed .

I'm sure we will do that one day .

So we just wanna line these up , line that one up with the end .

We're just gonna take and screw them together to make the base .

Remember I told you we were gonna use a PV C pipe to create that frame for our high tunnel .

Well , that has to be anchored .

What we're gonna do is we're gonna take this galvanized pipe and drive it down in the ground and leave it , stick out about six inches and then our PV C is gonna slide right over it to anchor it in place .

How are we gonna do that , Roger ?

We're gonna do it using this .

All right .

That should be pretty close .

Put that pipe in .

Take your hammer and your safety glasses .

Now , we picked the one inch pipe because it bends easily , but it does not fit over this galvanize that we drove in the ground .

So , what I did is I adapted a piece of pipe that's an inch and a quarter that'll slide over the galvanize .

So I'm gonna go up like this .

Get on mine .

Ok , I'm in now .

You got to lift up and bend .

Here you go .

Perfect .

Let's get another one .

All right to hold this in place .

We're gonna use this bracket .

I'm gonna hold it on here and you're just gonna put that screw right through the hole right there .

Great one to the other side .

Now .

Ok .

Come on over here .

Let me take and sink that one in for me .

This is going to set right in at this end , Jesse , let's talk about the work we've been doing .

We actually framed in two doors .

Now , that'll be great .

It'll make it easy for you to get in here and do your work .

But also if it does get really hot and it gets hot inside the tunnel , you can just open those doors and it'll ventilate and let the heat out .

That's great .

Now , we also put in a beam , two of them to stabilize the door frames and tie everything together and we've tied the rails to the top of this beam .

This would actually make a great place for some hanging baskets .

My wife's gonna love that .

Now we're gonna get the doors and put those up .

Let's do it .

All right .

We're ready to put this one in before we put it up .

I'm gonna put a shim right on the bottom .

Ok ?

You set the door right on top of that .

Good .

I'm silver .

Eat your heart out .

Ok , let's get the plastic on .

How are you doing ?

All right , great .

Look at that .

All right .

we're gonna fold the plastic over and get the whole thing tight and then we're gonna staple it into the two by four every three inches .

All right , Jesse , I'm gonna start cutting out around our door .

Now .

I want to make sure it doesn't rip .

Ok .

Ok .

Your high tunnel is done .

It feels hotter here .

Yeah .

Well , that's the point .

It's holding the heat in and that's gonna protect your plants .

They won't get frosted , they won't die .

You are gonna have vegetables all winter long .