DIY greenhouses are becoming more and more popular as people look for ways to save money and become more self-sufficient. A DIY greenhouse can be used to grow vegetables, fruits, herbs, and flowers, all while saving you money on your grocery bill. Not only that, but a DIY greenhouse can also help you reduce your carbon footprint. Now, I just need to eloquently explain that to my wife with the next project!
Today we’ll focus on a free-standing geodome greenhouse you can build using an old trampoline. Why an old trampoline? Well, we really just need the galvanized metal ring base to be solid and intact.
A geodesic dome, or geodome, is a structure that is made from a series of triangular elements. The triangular elements are connected to form a dome-like structure. This type of structure is extremely strong and has been used in everything from buildings to satellites.
The DIY trampoline greenhouse will be similar in shape but not technically geodesic. That being said, it will still provide ample space for you to grow a variety of plants and vegetables. And all the other benefits that come with this type of greenhouse are available.
Is a Geodome Greenhouse Right for you?
I chose the geodome-style greenhouse build because it’s a great option for those who want to learn how to build an effective DIY greenhouse that looks good on a budget. If you’re interested in learning how to build a DIY greenhouse, there are a few things you’ll need to consider before getting started.
Different Types of Greenhouses
There are two main types of greenhouses: free-standing and attached. And then from there, the choices only compound so you have to decide early. Free-standing greenhouses are ideal if you have the space for them, but they can be a little pricier to build because of all the materials.
Enter the trampoline (shoutout to Retired at 40 on YouTube). You can often find trampolines for pretty much free off Craigslist and Facebook. Just keep an eye out because you can also find them on the side of the road.
DIY Greenhouse Materials and Construction Supplies
If you’re doing the trampoline build, you’ll need:
- Hand gloves since you’re working with old metal and power tools
- Trampoline with steel ring base (get a free one or cheap one; don’t buy new)
- Metal-cutting pliers for the trampoline dismantling.
- 12 – 15 electrical 1″ PVC pipes for outdoors (this may depend on the size of your ring base) with “male” and “female” ends. You may want a different diameter that fits with the metal mounts of your specific trampoline base.
- PVC hoop connector or 3/8 by 6″ cross tee PVC
- Small box of self-tapping Screws
- Cordless Drill
- Saw (may not be necessary)
- Greenhouse plastic
Building a DIY Geodome Greenhouse out of a trampoline
The ring bases on trampolines are great starting points because they’re usually weatherproofed and strong since they’re meant to take a beating and handle hundreds of pounds. Also, the ring bases frequently have built-in little mounts for the trampoline support legs which you can now repurpose as mounts for your PVC pipes that will shape the dome.
Reminder: building with the trampoline may not lead to a technical “geodesic” dome but it gets pretty dang close.
Benefits of a GeoDome Greenhouse
- You generally don’t need a permit because it has no foundation.
- Pick up and Go Portability because of the lightweight design
- Roomier than you think, offering good ground access.
- Surprisingly sturdy in the wind and against snow
- Maximizes light penetration
Building a Geodome Greenhouse Frame with a Trampoline
Assuming you already have a trampoline secured, you’re ready to start. First off, you’ll want to safely dismantle the trampoline.
- Cut the fabric connecting the trampoline springs with metal-cutting pliers.
- Remove the canvas cover.
- Detach any additional poles or handle.
- Cut the straps that hold the trampoline together.
- Basically, you just want the big metal ring that has mounts to serve as your greenhouse “foundation”
If you measured the diameter of your mounts, you should be able to select PVC pipes that can fit in well or with little adjustment. Remember that we’re trying to save money and time here so use your best judgment. If you’re lucky or you measured right, the mounts on your trampoline will fit perfectly with your PVC pipes.
Now it’s time to build the frame of your DIY GeoDome Greenhouse. For this, you’ll need:
- PVC pipes
- Cross tees
- Carriage bolts
- Nuts and washers
You can find all of these at your local hardware store. The cross tees will help secure the frame and the carriage bolts will be used to attach all three cross tees, holding the PVC pipes, to each other securely. Remember that in this specific case, we had to cut approximately a 4ft long piece of PVC to extend the roofline, so it makes sense to cut that in half, place the cross tees in the middle, drill a hole through all of the cross tees and have a carriage bolt through all three holding them in place.
Your pipes and trampolines will probably differ due to sizing needs. Do what is best for you but please make sure the PVC pipes are glued and securely fashioned to the crosstree so you don’t risk it falling apart and causing injury.
How to Improve Geodome Greenhouse Rigidity
Next, we’ll build a smaller circle out of PVC pipes that we will connect to the frame to improve the rigidity of the structure. This is pretty basic so you just line it up based on comfort and drill a hole, screw it in, etc. Nothing about this is fancy.
This will also help once we begin attaching our plastic coverings. We’ll use zip ties to attach the plastic covering to this inner frame.
Assembling the Trampoline Geodome Greenhouse
Start with the base ring of PVC pipes and work your way up, attaching each pipe to the mount. It’s helpful to have someone help you hold the pipes in place while you’re screwing them in. Repeat this process until all of the PVC pipes are attached.
Now take the second, smaller ring of PVC pipes and start deciding where to place it, marking spots for drill holes and screws. It should likely be in a higher spot, a few feet underneath the top of the structure. And you can actually make more of these rings if you find out you need more stability for your greenhouse.
In our case, we’re only doing the additional internal ring since we don’t get a lot of wind in my part of town. At this point, you should have a pretty good idea of how everything is going to fit together.
DIY Attaching the Greenhouse Plastic Covering
Now it’s time for the plastic covering. In my case, I’m using 6mil greenhouse plastic. This is a really great option because it’s durable and it’s not too expensive. You can find it at your local hardware store or order it online.
To attach the plastic, I’m using zip ties. Again, nothing fancy, just cost-efficient. Start by draping the plastic over the frame and then use the zip ties to secure it in place. Make sure you leave enough slack in the plastic so that you can pull it tight when you’re ready to attach it.
To attach the plastic, start at the bottom and work your way up. Once you get to the top, pull the plastic tight and use the zip ties to secure it in place.
Now we’re ready to put the door in. I’m using a PVC pipe for the frame of the door and then attaching the plastic with zip ties.
To build the door, start by cutting a piece of PVC pipe to the desired height. Then cut two more pieces that will be used for the top and bottom of the doorframe.
Next, cut a piece of greenhouse plastic that’s slightly larger than the doorframe. Drape it over the frame and then use zip ties to secure it in place.
Now we’re ready to install the door. I’m using two hinges and a latch to secure the door shut.
To install the door, first drill holes for the hinges. Then attach the hinges to the doorframe with screws.
Next, attach the door to the frame with screws. Make sure the door opens and closes smoothly.
Finally, install the latch to keep the door shut.
And that’s it! You now have a DIY GeoDome greenhouse that you can use to grow your plants year-round.
Troubleshooting DIY Geodome Greenhouse with Trampoline
- If your base is not secured together or it comes apart from the PVC pipes fitting, you’ll want to secure the base together with your drill and self-tapping screws.
- If you’re finding that two PVC pipes are not tall enough for you to comfortably stand underneath, you may want to consider sawing a few feet off a 3rd PVC pipe and using that 3rd piece to connect the two PVC pipes in the middle and increase the total height as you prop them up.
- If your PVC pipes lay outside in the sun, they will be more flexible when you’re assembling them. Keep that in mind.
Image source: https://www.pinterest.com/pin/113856696821138476/