Building the "$50 Greenhouse"

My take on the "$50 Greenhouse." Construction cost: <$150.

With fall rapidly approaching and our FnL project underway, I've decided to build a greenhouse so I can stay motivated and growing over the winter months.

I want to thank David LaFerney at The Door Garden for his great post which inspired me to undertake this project.  I modified his design based on the noted weaknesses of his original concept to arrive at a design that is more robust, although the process of construction was very similar.

Planning

My initial design. The final was slightly modified.

After reading the Door Garden post (above) and reading some other articles, I decided to design a greenhouse that would be more likely to stand up to the sometimes monstrous snowfalls we can get here in the Front Range of the Rocky Mountains. Basically this meant going to a pointed (gothic) roof instead of the simpler curved (quonset) design, using 2x4's instead of 1x4's for the framing, and using plenty of ribs down the length of the house.

My original footprint was 7'x10', but after a visit to an organic farm in Boulder, where I got to see a large (16' x36' I'd wager)   aluminum-framed greenhouse full of beautiful vegetables, I followed the owner's advice to build mine "as big as you can," and so extended it as far as I easily could, arriving at 7'x16'.

This design is relatively easy to construct as it is very modular and can be streamlined further using "assembly line" methods. More on this later...

Material List

While I wanted to complete this project using as many reclaimed resources as possible, I none the less found myself at Home Depot more than once out of convince. The "$50 Greenhouse" is kind of a joke... the Door Garden one totaled ~$150.  I will total everything up here when the project is finished, already I think I'm at just under $150. It's not the big materials but the small stuff that gets ya! Here are the materials I used:

• 10' 3/4" PVC pipe (18 for 9 total ribs)
• 120º PVC connectors (9)
• PVC Cement
• 1 qt, matte-white exterior latex paint
• 8'-10' 2x4's (about 15 pieces)
• 2' 3/4" rebar (15)
• 4' "Tree support pickets" (6) - I'll find out what these are really called...
• 10' 1x1's (10)
• 4"x8" vents (2)  – Not sure if these will be useful, they look nice though!
• 2 1/2" Exterior sheeting screws
• 1 1/2" Exterior sheeting screws
• Bailing wire
• Utility knife (box cutter)
• 6 mil Clear plastic sheeting (more on this later)

Indispensable Tools:

• Circular saw
• Cordless drill
• 3/32 Drill bit
• Staple gun
• Sledge hammer
• Pliers / wire cutters
• Tape measurer / speed square
• Bubble level
• Helper piggy (no, you can't borrow mine)

Build that sucker

I find projects are much faster when you find repeatable steps and do them in an assembly line fashion. The three support members (the door, endwall and central rib) all have the same basic structure, so I started here and built all three at the same time.

I began by cutting (3) 2x4's to the width of my design's footprint (7'). Next I constructed the 'ribs' that attach to them. I cut PVC pipe into 7.5' sections and joined pairs together with 120º connector segments and PVC cement.

To connect the ribs to the 2x4, drill a small hole through the PVC at the bottom of one of the corners and fasten with a 2 1/2" screw. Then flex the rib by bringing the other end down and drilling/fastening the other bottom corner. With the pvc now in this nice shape, you can drill and fasten another screw on each side.

Next I constructed the uprights that brace the pvc and create the doorways. I measured 2' in on each side and laid 2x4's on these centers flush against the bottom beam. I traced the curve of the pvc pipe where it intersected the 2x4 and cut the approximate straight angle. (Err on the long side for your first cut. You can always make something shorter but you can't make it longer again!) You could use a reciprocating hand saw to cut a curve, but a straight cut will get you close enough.

Once you have done this once and have an upright that fits nicely, you can use this piece as a template and to cut the remaining 5 uprights.  Attache the uprights to the base boards and connect to them to the pvc by drilling holes and driving screws. The screws will probably have to go in at two different angles so as not to punch through where the angles converge.

The two end sections were supported with horizontal cross members because I originally planned to have doors at both ends.  I later opted for one door for simplicity's sake. The central section had an angled design for more headroom inside the greenhouse. If this is too fancy for you another horizontal beam would work fine. However, after I built this center section it made me wish I had built both end sections the same way as it is much stronger and prettier and you can literally do chin-ups from the frame above.

Awww, sheeeeeet....
With these three sections built it was on to the plastic sheeting!
I know better than to use non UV-treated plastic, but I tried several local suppliers for green house plastic and some of the prices I got back were "prohibitive" to say the least, as much as $3.25/sq ft with the smallest order being 100 sq ft!  There are suppliers online, but as I am impatient and want to finish this this weekend, I swallowed my better judgment and bought the non UV-treated 6 mil sheeting from home depot.  I'll see how it goes...

Regrettably I did not take photos of the plastic sheeting procedure as my wife and I were battling breezes, but I followed the method that David used, basically wrapping the ends like big christmas presents, pulling the excess back and stapling it behind, then cutting off the remaining material.

This shot is from later in the process but shows both the horizontal frame piece and the plastic wrapped and stapled behind the end section. You can also see how the vent is attached.

The door section was wrapped just like the other end. To create the opening I cut out a square hole that was 3-4" smaller that the door frame, then cut in at angles toward each corner of the doorway. I pulled the resulting flaps back and stapled them to the door frame.

Supports

You can see two of the supports in the photo above, after carefully measuring I pounded the pickets in where the door frames were.

Then I dug a small trench where the bottom frame piece would lay.

 

I laid the section in the trench and filled in with dirt underneath the beam until it was level, then filled the surrounding space.  I think this will give the sections a bit more stability and it lowered the floor beam for a nice step over height.  I affixed the doorways to the posts with bailing wire.  You can see the wire in the following pics.

With the three support sections installed it's time for rebar. I used a string to make a straight line between the support sections, then measured the distance (three ribs between each support) and pounded 2 ft rebar into the ground until 4-5 inches remained.

Then I cut and assembled the remaining ribs and slid each end onto the protruding rebar.

Finally starting to look like a green house!  I adjusted each rib on either side to make sure the heights were the same and that the central spine was fairly straight.  For some this meant digging down around the rebar to slide the pipe further down, others needed to be propped up with piled dirt.

Brace Yourself

Next I installed the braces between the ribs. I just used 2x2's mounted with screws from the inside. I connected the brace beams to the support members at the 2x4's rather than the PVC for added support.

Top and bottom!

 

I left the bottom braces short on the ends because I had no place to attach them to the doors (on account of my wrap job). I regret this (I'm a perfectionist) but structurally it should be more than ok. 

Take Cover

 

Next, covering the frame.  I'm using 20ft sheeting, so I used this dimension for the width of the house, and cut ~17" for the dimension that goes over the top.  I used a piece of plywood, a speed square and a scrap 2x2 to ensure a nice straight cut.  Since this small cut will unfold to be a 20ft edge, the straighter the better!

Then I folded and stapled 2x2 sections into each side to weight and straighten the covering.

 

I pulled the covering over the house and pulled it taut on both sides.  At each end, I cut a slit about 4 inches from the peak of the roof, then cut off the excess following the curve of the house, leaving enough to fold over and attach.

Finally, I used a combination of staples and clear duct tape to shape and attach the excess sheeting to the sides.

I could have done this earlier, but I decided to add a central beam down the center of the roof to help prevent snow and water accumulation.  I cut scrap PVC to length and joined them with straight connectors, then used tiewraps to attach the pole at each 120º connector at the apex.

Who is Jim Eagle?

And voila!

 Next I will be filling the inside with compost and mulch and attaching a door. I will post more pics when this is completed!

~r

Wasted on Grass

The following is an excerpt from Food Not Lawns: How to Turn Your Yard into a Garden and Your Neighborhood into a Community by H. C. Flores.

French aristocrats popularized the idea of the green, grassy lawn in the eighteenth century when they planted the agricultural fields around their estates to grass to send the message that they had more land than they needed and could therefore afford to waste some. Meanwhile French peasants starved for lack of available farmland, and the resulting frustration might well have had something to do with the French Revolution in 1789.¹¹

Today fifty-eight million Americans spend approximately thirty billion dollars every year to maintain more than twenty-three million acres of lawn. That’s an average of over a third of an acre and $517 each. The same-sized plot of land could still have a small lawn for recreation and produce all the vegetables needed to feed a family of six. The lawns in the United States consume around 270 billion gallons of water a week—enough to water eighty-one million acres of organic vegetables, all summer long.

Lawns use ten times as many chemicals per acre as industrial farmland. These pesticides, fertilizers, and herbicides run off into our groundwater and evaporate into our air, causing widespread pollution and global warming, and greatly increasing our risk of cancer, heart disease, and birth defects. In addition, the pollution emitted from a power mower in just one hour is equal to the amount from a car being driven 350 miles.

In fact, lawns use more equipment, labor, fuel, and agricultural toxins than industrial farming, making lawns the largest agricultural sector in the United States. But it’s not just the residential lawns that are wasted on grass. There are around seven hundred thousand athletic grounds and 14,500 golf courses in the United States, many of which used to be fertile, productive farmland that was lost to developers when the local markets bottomed out.¹²

Turf is big business, to the tune of around forty-five billion dollars a year. The University of Georgia has seven turf researchers studying genetics, soil science, plant pathology, nutrient uptake, and insect management. They issue undergraduate degrees in turf. The turf industry is responsible for a large sector of the biotech (GMO) industry, and much of the genetic modification that is happening in laboratories across the nation is in the name of an eternally green, slowgrowing, moss-free lawn.

These huge numbers are somewhat overwhelming, if not completely incomprehensible, but they make the point that lawns not only are a highly inefficient use of space, water, and money but also are seriously contributing to the rapid degradation of our natural environment.

I have traveled in the United States, Canada, Europe, Mexico, and South America, and most of the people I’ve met will agree that eating organic food is a good idea, as are recycling, conserving wilderness areas, and otherwise taking care of the earth. Nevertheless, as a society we continue to degrade our lands and cultures with pollution, mining, logging, a toxic and devastating agriculture, and a string of other abuses. We display our rejection of ecological responsibility through an irreverent consumer culture rife with waste and injustice, and we demonstrate our affluent denial by growing miles upon miles of homogeneous green lawns.

If we truly feel committed to treating the earth and one another with equality and respect, the first place to show it is by how we treat the land we live on. It is time to grow food, not lawns! The reasons include reducing pollution, improving the quality of your diet, increasing local food security, and beautifying your surroundings, as well as building community and improving your mental and physical health. You will save money and enhance your connection with the earth and with your family.

Whatever happens, you may still choose to keep a small lawn for playing croquet and sunning with the chickens. Good for you! The term Food Not Lawns is meant as a challenge to the notion of a homogeneous culture; it is not a call for the eradication of all green grassy places.

A small lawn, incorporated into a whole-system design, helps provide unity and invites participation in the landscape. Lawns offer a luxurious and comfortable place to read, stretch, or exercise. If you are the kind of person who uses a space like this, you should have one somewhere near your house.

And why not enhance the lawn with edible flowers, fruits, vegetables, or other useful plants? Or what about turning your whole yard into an organic food garden and using a local park, school, or natural area for recreation? If we can change our landuse philosophy from one of ownership and control to one of sharing and cooperation, we can renew our connection with the earth and one another and thus benefit through increased physical and mental health, an improved natural environment, and stronger local communities.

What have you got to lose besides a few blades of grass?

---

1. Sarah Robertson, “History of the Lawn,” Eugene Register-Guard, 26 April 1995.
2. Richard Burdick, “The Biology of Lawns,” Discover Magazine 24, no. 7 (July 2003).

Prelude

There I was: mowing my front lawn for the first time in over a month, the shag carpet of seeding heads and weeds being shorn to reveal the thin dying stalks below. Not only had the lawn not been mowed for a month, but it had been watered hardly at all, and so earned the title of ugliest lawn on the block.

This I was fine with.

However, looking at my neighbor's lush, perfectly manicured turf I realized they must perceive my wife and I as uncaring and lazy, indeed in our culture it seems the appearance of one's lawn is an extension of the people who own it. But something was sickly backward in this equation: our lawn was ugly and dying because I did care. I cared about dumping chemical herbicides and fertilizers on the ground, I cared about wasting copious amounts of water maintaining something that has no business growing in the aired high plains of Colorado; but above all, I cared about the time I was expected to waste caring for a plant that I could not eat or use in any meaningful way.

I realized that a large percentage of homeowners didn't even care for their own lawns. They literally paid companies to come dump poison on their property and drive around on little tractors that spewed both noise and fumes, and they had expensive mechanical systems that woke up every morning to drain their bank accounts while spraying valuable water onto sidewalks and sod.  All of us living like hermit crabs – floating blankly above a homogeneous, disconnected landscape.

In a flash I saw this wasted mat of brown grass not as "my lawn," but as the little rectangle of planet earth that I called home – a gift of unfathomable beauty and potential. I realized that we all have the power to free our little pieces of earth from the oppressiveness of our stupidity and live connected to this amazing planet from which our very lives spring.

Into my mind leapt the mantra, "food not lawns." I had heard this somewhere before, but now it was resounding through my ears over the roar of the lawn mower. Food! Not lawns!  Food! Not Lawns!

I decided right then and there to live the rest of my life differently. To be connected to the land I lived on surrounded by the amazingness of life.

Goodbye, lawn.