How to Build a Dome Greenhouse

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This simple, dome greenhouse is easy-to-make and an expensive way to extend the growing season in your garden both in spring and fall.

For more ideas, my Lean-To Greenhouse Project.

Square Foot Gardening with Kids

This project is from the book, Square Foot Gardening With Kids by Mel Bartholomew. If you want to try a frugal way to add weeks to your growing season, this is an option.

Square Foot Gardening With Kids | Amazon

If you’re familiar with square foot gardening, you know it’s a simple approach to organic gardening:

In a square foot garden, a raised planting box is filled with special soil blend and divided into 1-foot squares.
Each square is planted with different vegetables, herbs, or flowers.
Depending on how much space the mature plant needs, you may grow anywhere from 1 to 16 plants in any given square.
Because the soil is all new, almost no weeding is needed. It’s mostly just water and wait.

This approach to gardening appeals to kids because it’s methodical and easy to do, step by step.

The book is written for adults who want to create an edible garden with kids and includes how to make a raised bed, prepare it for planting, planting ideas (veggies, flowers, herbs), and how to make a greenhouse dome.

Dome greenhouses are used to extend the growing season.

The plastic cover helps capture and contain warm sun.

This means you can start plants early in spring and keep them growing later into fall. If you’re like me, this may turn into year round vegetable gardening in a cold climate.

This project is quite fast and easy to do and probably appeals to kids who like the idea of building a tent!

Build Your Own Dome Greenhouse

Excerpt from Square Foot Gardening With Kids by Mel Bartholomew

1Gather Supplies

Once at the home center, head to the plumbing department.
Ask an associate there for ½ -inch pvc pipe, then tell them you would like two 10-foot lengths.
You’ll also need to buy a small package of plastic cable ties (you can find them in the electrical department) and
a heavy plastic drop cloth measuring at least 12 foot by 12 foot (this is called 6-mil polyethylene sheeting).
Now you’ll need to pick up four 18-inch long, ½ -inch (no. 4) pieces of rebar and four 9-inch long pieces of PVC tubing, but if you can’t find them that’s OK— they’re mostly optional.
Don’t forget to let your child help load and unload the car: it’s a great habit to get them into.

2Attach Rebar

Step 2: Installing a pipe for dome greenhouse.

Here’s the best way to anchor your dome: hammer a piece of rebar into each of the inside corners of the SFG box.

Then, slip one piece of ¾ -inch PVC over each piece of rebar. Slip one end of one of the ½ -inch PVC pipes inside the ¾ -inch PVC.
If the child has any trouble doing this, they should enlist the help of an adult.
Here’s the easiest way to anchor your dome: with the box full of Mel’s Mix (recipe is in the book), poke the end of one piece of tubing into the mix and press it all the way down to the bottom of the box.
Then, bend it across to the opposite corner and set the other end into the mix the same way.
The ½ ” PVC tubing bends well and doesn’t kink or break.
If you are using rebar and tubes, bend the PVC pipe over and secure the opposite end of the pipe onto the rebar in the diagonal corner.

3Make Second Arch

Make a second arch crossing the first, with the ends secured in each corner in the same way.
If you did not anchor the tubes onto rebar, it’s probably smart to drill a pilot hole into the end of each tube and drive a deck screw to help keep things from blowing away.

4Secure Arches

Step 4: Securing arches on dome greenhouse.

Secure the point at which the arches cross with a nylon cable tie.
Sometimes little hands have a hard time working with plastic ties, so you may need to ask Mom or Dad, or your older brother or sister for help doing this.

5Prepare Cover

Step 5: Cutting plastic for dome greenhouse.

Cut a piece of sheet plastic that’s big enough to cover the whole dome, with a couple of feet extra on each edge of the box.

6Install Cover

Step 6: Covering dome greenhouse with plastic cover.

Drape the plastic over the arch, so there is an equal amount on all sides.
You’ll need to fold over the sheeting at the corners.
Put bricks or stones on the edges of the sheeting to make sure it doesn’t blow away in the wind.