Give Plants a Big Head Start With Simple Greenhouse
By T. Jeff Williams
We all know how fickle weather can be. Cold when it should be hot, and vice versa. This can be hard on your flower and vegetable plants. But a simple yet durable greenhouse, as described here, can give your plants an early start in winter, keep them thriving in summer, and protect them from fall frosts.
The greenhouse is made from nothing more than some 10-foot lengths of 1/2-inch PVC pipe and a roll of clear plastic sheeting. But how it's put together is what makes it unique, as you will see. It is very simple and you can put it up in about 30 minutes. You'll get a great head start on your summer production, and when warm weather really arrives, you can break it down in minutes and store until needed again.
For this 4 by 12 foot greenhouse, here is your parts list:
- 9 PVC pipes, 1/2-inch by 10 feet long.
- 6 stakes
- Roll of twine
- 1 roll plastic sheeting, 10-foot by 25-foot, 4 mil
- Optional for hard ground: 18 pieces of 3/8-inch rebar each two feet long.
Layout
The first step is to lay out the greenhouse dimensions on the ground so the structure will be square, meaning everything properly spaced. Lay out one side by driving three stakes in a line six feet apart. Now, lay out the other side four feet away by placing the other three stakes in line parallel with the first row. Measure the diagonals: if the measurements are within an inch of each other, it's close enough for this project.
1. Stakes and string mark the layout of the four-foot wide by 12-feet long greenhouse dimensions.
Construction
If the ground is soft enough, push one end of a 10 foot length of PVC at least six inches into the dirt beside the first stake, then bend it over and push the other end into the ground beside the stake on the opposite side.
If you have hard ground, drive two-foot lengths of 3/8-inch diameter rebar into the ground and then slip the ends of the PVC over that. These pre-cut lengths are available in many hardware stores.
2. The PVC pipes can be pushed directly into the ground if it is soft enough. If not, drive two-foot long lengths of 3/8-inch reinforcing rod into the ground and slip the pipe over the ends.
After bending PVC pipes into place at both ends and the middle of the greenhouse, put three more pieces in place about two inches away from the first ones. You now have a set of double hoops at both ends and in the middle, or the six-foot mark.
Spread the plastic sheeting over all the hoops and adjust until equal on both sides and ends.
3. Position one end of the pipe in the ground, bend it in an arc and push the other end into the earth.
4. Put two more pipes in place at both ends and the middle, keeping them about one inch away from the existing pipes. Now cover the frame work with the 4 mil plastic sheeting and anchor the ends with large rocks or other weights.
Now here is the clever trick to this greenhouse: to hold the plastic covering in place, bend the last of the PVC pipes between those already installed, but outside the plastic sheeting.
This will lock the sheeting down but still allow you to slide the plastic up on the sides for easy access to the plants, or to provide circulation during the heat of the day.
5. Hold the plastic sheeting in place by positioning the third piece of PVC between the two existing hoops, but on the outside of the plastic. This wedges the sheeting between the two supporting pipes on the inside.
Gather the material on the ends in a bunch and weight it down with some large rocks or other heavy items. You can hold the sides down with a length of 2x4 or some bricks or rocks.
This little greenhouse with big potential will give your plants year-round protection. It's also a great way to keep tomatoes going even after the fall rains begin.