Should I build a greenhouse?

[fatjay]

Greenhouses are houses that people grow things in that get hot in the cold. That's all I know about them. So here's what I have.

I want to grow food year round. Lettuce, cucumber, tomato, cilantro, garlic, carrot, etc. Can I use a green house year round? I would be dedicating part of my garden area to it. I was thinking a 10x20'. Do they need to be vented? Temp controlled? Auto misting?

Please fill my brain with everything about how a green house is properly used.

 

[Jstpssng]

Short answer, Yes.

In your region you will be able to grow many crops year round. "A Greenhouse" can be many things though. How permanant do you want it? You can do a simple hoop house; metal conduit half circles, covered with plastic. (I have one of these, 14x40. It was my father's last hoop house, and I had fun with it but now need to put it on a better site and buy new plastic.)

You can go a bit further, building a wood frame and covering that with plastic. You can build a wooden frame and cover it with polycarbonate.

10MM Twinwall Polycarbonate Sheet 48x96 (This is the route I hope to go.)

If you really want to get hardcore you can build a pit greenhouse. How to Build a Pit Greenhouse on Your Homestead – Mother Earth News

If I was 30 years younger, this is the route I would pursue.

 

[fatjay]

I was going to get a HF carport then wrap it in 5mil clear plastic sheeting, then frame a doorway and windows out. Then basically do raised beds inside. It's 10' wide so I was thinking 3' on each side with a 4' in the middle. I have a south facing back area, but if it gets to hot in the summer, i'll cook my plants.

 

[bigtiller]

I was going to get a HF carport then wrap it in 5mil clear plastic sheeting, then frame a doorway and windows out. Then basically do raised beds inside. It's 10' wide so I was thinking 3' on each side with a 4' in the middle. I have a south facing back area, but if it gets to hot in the summer, i'll cook my plants.

With those plans, it doesn't sound to likely you will be successful with year round growth.

For that you will need supplemental heat, insulated windows, temperature & humidity controlled exhaust fan, and fresh water.

Ideally it would be connected to the south side of a small garage so egress/ingress would not disturbed the conditioned air as much.

But your plans would be great for getting a jump start on the growing season outside.

 

[fatjay]

With those plans, it doesn't sound to likely you will be successful with year round growth.

For that you will need supplemental heat, insulated windows, temperature & humidity controlled exhaust fan, and fresh water.

Ideally it would be connected to the south side of a small garage so egress/ingress would not disturbed the conditioned air as much.

But your plans would be great for getting a jump start on the growing season outside.

I can move mountains. If what I plan is wrong for what my intent is, please correct it, and I will make proper adjustments. What I know is limited, but what I can do is unlimited. Tell me what you would do if you were planning a 10x20 greenhouse.

 

[Yander]

Year-round growth depends on what you are growing year around. Some of the things you mentioned can easily be grown year round with just an unheated hoop house or greenhouse.

You mentioned cucumbers; those are heat loving vegetables and would require some heat in your greenhouse. They don't like cool.

I would start by deciding what it is you want to grow and then look at the temperatures that that plant needs to grow in.

But yes, if you want to grow year round, a greenhouse is definitely a must in PA.

There is a book by Elliot Coleman called the winter harvest handbook. If you're serious about this I would buy that book and read it.

In a nutshell, in the book he says that for each layer of greenhouse fabric you reduce your growing zone by one and a half.

Example: So in PA one layer of greenhouse fabric would be like you were in say Tennessee. A hoop house inside of a greenhouse, or two layers, would put you in a Georgia zone.

Those are guesses without looking at a growing zone map just for example of how it works.

 

[Streetcar]

Greenhouses are houses that people grow things in that get hot in the cold. That's all I know about them. So here's what I have.

I want to grow food year round. Lettuce, cucumber, tomato, cilantro, garlic, carrot, etc. Can I use a green house year round? I would be dedicating part of my garden area to it. I was thinking a 10x20'. Do they need to be vented? Temp controlled? Auto misting?

Please fill my brain with everything about how a green house is properly used.

With those plans, it doesn't sound to likely you will be successful with year round growth.

For that you will need supplemental heat, insulated windows, temperature & humidity controlled exhaust fan, and fresh water.

Ideally it would be connected to the south side of a small garage so egress/ingress would not disturbed the conditioned air as much.

But your plans would be great for getting a jump start on the growing season outside.

As big tiller said year round requires supplemental heat and ventilation . I would start with simple hoop house to extend season on each end. If you like results you can expand. From my limited experience rodents love greenhouses

 

[David Wayne]

Shorter daylight hours means you will need grow lights.

David

 

[Jstpssng]

As big tiller said year round requires supplemental heat and ventilation . I would start with simple hoop house to extend season on each end. If you like results you can expand. From my limited experience rodents love greenhouses

Depends on the crop. Even up here people have been growing cole crops in winter, with compost as the only heat source. Carrots are another which will grow that way. Tomatoes, cucumbers and other warm weather crops do need heat; but you can grow those inside, with a grow light to extend the daylight.

Another option I've seen people use rather than the HF greenhouse is the frame of a temporary shelter; buy a sheet of 6 mil plastic after the original covering fails.

One thing you need to consider is snow load. Make sure that you leave room on each side to plow or blow a path to keep it from building up. It also would be worthwhile to build a gravel pad to elevate the footprint of the greenhouse; that way you don't risk "touching" the covering with your bucket, plow or blower.
Please don't ask me how I know that!!! It will make cleaning the snow all around easier.
I also would consider a small heat source anyways to take the chill off while you are out working there.

 

[Paddy]

As mentioned above, very large compost piles with water filled tubing has been used to heat green houses. The material mix, saw dust and wood chips has to be controlled with water infusion and nitrogen to keep it hot. but a well constructed compost pile can generate heat all through the cold season.

 

[Jstpssng]

Some friends just built a new garage, and put an attached greenhouse on the westerly side. It's about 8 feet wide and 24 long. They already are picking salad vegetables, and will have potatoes by Mother's Day. I believe they do use a small electric heater at night to keep things from freezing, but everything is also grown on a bench rather than on the ground; and it's built on a slab so they aren't getting any heat from the ground.

 

[MossRoad]

I was going to get a HF carport then wrap it in 5mil clear plastic sheeting, then frame a doorway and windows out. Then basically do raised beds inside. It's 10' wide so I was thinking 3' on each side with a 4' in the middle. I have a south facing back area, but if it gets to hot in the summer, i'll cook my plants.

That is exactly what my wife and I are doing. Neighbor gave us a portable car shelter frame after his cloth cover rotted out.

However, we are going to use it for like others have said... early spring start, later fall harvest, and keeping the rabbits and woodchucks at bay. I don't think it would withstand a snow load in winter.

I plan on pulling the top/side covers annually.

Here's the start we got on it last weekend.

I pulled the sides in to make it 8' wide and more vertical of side walls. And I removed some length between the arches to make it 14' long. It was cheaper for me to purchase a wood screen door for $34 than build one. I framed the ends to make it more rigid, and I installed metal channel and wiggle wire to hold the plastic. It's 6 mil greenhouse plastic.

Before I install the top and sides, I'm going to dig holes under each corner and add a few bags of cement and some rebar to hold it down. The wind load will be pretty good. I'm also going to lay a wall of concrete blocks around the walls to help deter the woodchucks, as well as lay some chicken wire around the outside edges on the ground to deter digging.

We're putting 1/2 x 1/2" hardware cloth around the bottom 3' of the whole thing, door included.

I have some flexible clear vinyl cloth like you'd see in Jeep convertible windows that I'm going to stick on the inside of the door with magnets to allow for ventilation or closed up. Same thing on the vent on the other end.

The bottom 2' on the sides will be able to be rolled up in warm weather, and the hardware cloth will keep the critters out.

One thing I do wonder about is pollination. I think bees can get through the hardware cloth, but I might end up having to hand-pollinate. Still have to read up on that.

(click to enlarge)



I'll be interested in your project.

 

[Jstpssng]

One thing I do wonder about is pollination. I think bees can get through the hardware cloth, but I might end up having to hand-pollinate. Still have to read up on that.

What will you be raising? Many cucumbers are self pollinating. Tomatoes are easily done with a Q-tip, as you indicated.

 

[MossRoad]

What will you be raising? Many cucumbers are self pollinating. Tomatoes are easily done with a Q-tip, as you indicated.

Tomatoes and cukes. I've done the tomatoes by hand in the past when we had no bees.

Probably salad greens, and some carrots. And some flowers for the wife.

Pretty much whatever we feel like.

Gonna go back to Mel Bartholomew's Square Foot Gardening methods. Very productive in a small space. I bought is first book after I watched his show probably 30 years ago.

Square Foot Gardening Foundation

Learn about the Square Foot Gardening Method created by Mel Bartholomew. Find tips and resources, locate a Certified Instructor, and read our newsletter.

squarefootgardening.org

 

[Jstpssng]

Tomatoes and cukes. I've done the tomatoes by hand in the past when we had no bees.

Probably salad greens, and some carrots. And some flowers for the wife.

Pretty much whatever we feel like.

Gonna go back to Mel Bartholomew's Square Foot Gardening methods. Very productive in a small space. I bought is first book after I watched his show probably 30 years ago.

Square Foot Gardening Foundation

Learn about the Square Foot Gardening Method created by Mel Bartholomew. Find tips and resources, locate a Certified Instructor, and read our newsletter.

squarefootgardening.org

I have a two acre field. The first garden I planted on July 4, 2002 did great. There were 30 foot tall gray birch trees growing in the morning. I attacked a spot with my chainsaw, dug the stumps with my little backhoe, and by the end of the day had planted carrots, corn, tomatoes and a few other items. It did great. Over time I expanded and in 2009 had the entire 2 acre field reclaimed. Yet it seems like every year I am dismally disappointed.

I am going back to raised beds, so that I can control the soil better. I started two years ago, raising some of my root crops in soil which I had "cooked" in my father's old soil sterilizer... raising it to 160 degrees F to kill all of the weeds. I also cook pig manure before using it... no need to risk trichinosis another disease.
The snow is melting fast right now. Last fall I planted onions and garlic in one of my smaller beds. Yesterday it was still under snow... I was up there just now and there are green garlic tops sticking up an inch or so. Or maybe it's onions, I don't recall what I planted where.
There's a method of raised beds where you line the bottom with logs, then gradually build it up. That's what I am going to do, although it will probably be slabs lining the bottom. That's what is nice about having a bandsaw, it's better than going to the lumber yard.

 

[Eaglesfate]

A lot to think about, I have always heard the green house should be laid out West to East for the greatest sun exposure over the day. If I had the ground I would go with a in ground green house similar to the Green house in the snow.

 

[Jstpssng]

^^^^ That's what I meant when I referred to a pit greenhouse, although I didn't realize how well they worked.
My father would have loved this video. I think I miss him more after watching it than I ever have.

Alzheimer's sucks.

 

[Jchonline]

I was going to get a HF carport then wrap it in 5mil clear plastic sheeting, then frame a doorway and windows out. Then basically do raised beds inside. It's 10' wide so I was thinking 3' on each side with a 4' in the middle. I have a south facing back area, but if it gets to hot in the summer, i'll cook my plants.

Add fans at each end one intake one exhaust to help with heat dissipation.

I would be more concerned about the winter. Are you going to keep it heated?

 

[newbury]

Have you looked into "cattle panel greenhouse"?
google link
I just bought 5 panels (16'x4'2") from TSC for ~$175. Plan on building this summer for fall & winter. That with about a 20'x16'x6mil roll of "greenhouse" plastic (~$30) builds a minimal greenhouse.
Note in many places TSC only stocks the cattle panels in the spring.

 

[Jstpssng]

Have you looked into "cattle panel greenhouse"?
google link
I just bought 5 panels (16'x4'2") from TSC for ~$175. Plan on building this summer for fall & winter. That with about a 20'x16'x6mil roll of "greenhouse" plastic (~$30) builds a minimal greenhouse.
Note in many places TSC only stocks the cattle panels in the spring.

That's an interesting idea. You probably can achieve the same thing with concrete wire mesh.
One easy way to keep it from collapsing from snow weight is to have poles of some type supporting the ridge line. There are times when you won't be able to clear it right off.
My father once had a 96 foot greenhouse with a fiberglass covering which he did this for every year. One snowy morning that was going to be his project, but it came down before he had a chance to do that. I don't recall what he did to replace the space that year, but suspect there was some scrambling once the snow melted in spring.