Build your own DIY polytunnel design utilizing a handful of items. Small polytunnel gardening and greenhouse designs are on the rise and an inexpensive tool to utilize for growing food.

Living on the coastal side of the Pacific Northwest, outside of Seattle, Washington, has its challenges when it comes to gardening. Especially, for individuals like myself who grow food in the mountains.

We struggled for over 6 years with growing items such as melons, tomatoes, and peppers. The temperatures were too cool for these warm weather items. However, this did not stop me from trying. And failing.

I had decided that growing fruits and vegetables which required warmer temperatures would not happening on our property. Because of this the decision was made to not waste any garden space on these items. Instead the focus would be directed to cool weather and summer items which had a shorter maturity time.

That is, until I planted the summer garden of 2020.

The DIY Polytunnel

Spring and early summer of 2020 was horribly cold and wet, remaining this way through the middle of July. The tomatoes had no hope of thriving and by mid-July were dying.

At this point there was nothing to lose, each plant was cut back to 6 inches tall and stripped of their leaves. They were a sad looking lot, but I had high hopes they’d make a comeback.

In addition to a good old fashioned hair cut, a DIY polytunnel was constructed over the raised bed. And that, my friends, was the game changer.

In a course of 10 days the San Marzano tomatoes began to make an incredible comeback. Unfortunately not quick enough to utilize as a red tomato but a lot green tomatoes sauce was about to be preserved.

A polytunnel gardening is a great gardening tool for those who reside in cooler temperatures. There are no ifs, ands, or buts about it. The best part? A large or small polytunnel can be utilized in any type of garden, raised bed, market, or potager garden.

Designing a Potager Garden or a Small Kitchen Garden

Build your own DIY Polytunnel

There are many options available when it comes to purchasing polytunnel kits, however, these kits are spendy. The cost of building your own polytunnel is a fraction of what a kit costs.

The material for this particular DIY polytunnel will cost you roughly $40 and takes less than 30 minutes to construct. Not to mention, this polytunnel gardening method is easily movable, making crop rotation easily achievable with the use of this small polytunnel.

Polytunnel Greenhouse

Aside from utilizing this DIY polytunnel for gardening it can also be used as a polytunnel greenhouse. With a few modifications, such as adding a door, this hoop style greenhouse is ideal for those who seek to build a functioning, inexpensive greenhouse.

Also, a polytunnel greenhouse can be moved with each season to accommodate the location of the sun. This is ideal for those who have minimal sunlight due to the property size or large trees blocking the sun.

Polytunnel Gardening

Polytunnel gardening is perfect for those who struggle with cooler temperatures year-round. This method is inexpensive, which means multiple small polytunnels can be utilized throughout the garden.

As mentioned above, growing warm weather foods can be a struggle. Especially if you seek to grow true warm weather crops. Utilize a DIY polytunnel to grow the following items:

tomatoes
melons
peppers
okra
eggplant

The use of a small polytunnel will help to ensure a successful growing season.

Build a Small Polytunnel

The design for this particular DIY polytunnel can be used for both raised beds, traditional or market, and kitchen gardens.

raised garden beds – utilize either rebar or conduit brackets to support the small polytunnel
traditional gardening or market gardening – utilize rebar to support this polytunnel

At the end of the season, carefully disassemble the DIY polytunnel and store away until the next growing season. Locations with mild winters are capable of utilize this tool year-round. However, I would suggest purchasing a heavier plastic than the 6 mil mentioned, especially for windier locations.

Material

The material found on this list can be purchased at any large or small hardware store. Also, the size of this particular small polytunnel is 6 feet long X 7 feet wide X 7 feet tall. Feel free to modify the length as you see fit. Keep in mind, the longer the polytunnel, the more it will need to be braced for additional support.

8 1/2 inch PVC pipe, 10 feet long
8 1/2 inch rebar or conduit brackets
12 1 1/4 inch Phillips head screws when using conduit brackets
4 couplers to fit 1/2 PVC pipe
1 package 6 mil plastic, or thicker if needed
12 large plastic spring clamps to secure the plastic to the PVC pipes
2 2X4 8 feet long
6 standard rebar tie wire, 16.5 gauge
2 1X2 6 feet long, optional

Equipment

In true DIY fashion, the equipment needed for this small polytunnel consist of items which you own.

scissors for cutting the plastic
cutting pliers for cutting and securing the wire tie
hammer or battery operated drill (Phillips head drill bit) for securing the PVC pipe

Instructions

For the sake of the article, based on how we constructed our DIY polytunnel, the instructions are written using rebar instead of conduit brackets.

Drive the rebar 1 foot into the ground every 3 feet and one centered on each end. Or secure the PVC pipe to the raised bed every 3 feet using the conduit brackets.
Slip the PVC pipe over the rebar. Using the coupler join two PVC pipes together.
Create a ridge support by joining 2 PVC pipes with a coupler. Run the ridge support under the hoops, then slip each end over the rebar if utilizing the traditional or market garden polytunnel. Make sure to secure the ridge support to the existing hoops using tie wire.
To provide addition support to the frame place a 1X2 horizontally midway between the ground and ridge support. Secure the 1X2 using tie wire at every PVC pipe.

Steps for a Raised Bed

Cut the plastic at least 22 feet long. Stretch out the plastic over the hoops.
Next, on both side, roll-up the 2X4 with the bottom end of the plastic, wrapping twice, do this to both ends. Secure the plastic to the 2X4 using the tie wire every 3 feet.
On one side secure the 2X4 to the PVC frame using a 12-inch piece of tie wire to prevent it from moving in the wind.
On the secured side, from ground level to the ridge, secure the plastic to the PVC pipe by loosely wrapping the plastic around the PVC pipe multiple times. Pierce the tie wire through the layers of plastic and around the pipe. The purpose of wrapping the plastic loosely is to prevent the plastic from tearing in a gust of wind. Repeat this step at the opposite end.
On the opening side, use the spring clamps to secure the plastic to the frame.

Building Unique Raised Garden Beds

Steps for a Traditional or Market Gardening

Cut the plastic at least 22 feet long. Stretch out the plastic over the hoops.
Next, on both side, roll-up the 2X4 with the bottom end of the plastic, wrapping twice, do this to both ends. Secure the plastic to the 2X4 using the tie wire every 3 feet.
Secure the 2X4s to the frame to prevent it from moving in the wind. Using a 12-inch piece of tie wire secure the 2X4 to each end of the frame on both sides.
At each opening, to prevent the plastic from tearing at the ends, loosely wrap the plastic around the PVC pipe multiple times. Pierce the tie wire rough the layers of plastic and around the pipe. The purpose of wrapping the plastic loosely is to prevent the plastic from tearing in a gust of wind.

Yield: 7 feet long

DIY Polytunnel

Build your own DIY polytunnel design utilizing only a handful of items. A small polytunnel gardening and greenhouse design is on the rise and an inexpensive tool to utilize for growing food.

Active Time 1 hour

Total Time 1 hour

Materials

8 1/2 inch PVC pipe, 10 feet long
8 1/2 inch rebar or conduit brackets
12 1 1/4 inch Phillips head screws when using conduit brackets
4 couplers to fit 1/2 PVC pipe
1 package 6 mil plastic, or thicker if needed
12 large plastic spring clamps to secure the plastic to the PVC pipes
2 2 X4 8 feet long
6 standard rebar tie wire, 16.5 gauge
2 1 X2 6 feet long, optional

Instructions

Drive the rebar 1 foot into the ground every 3 feet and one centered on each end. Or secure the PVC pipe to the raised bed every 3 feet using the conduit brackets.
Slip the PVC pipe over the rebar. Using the coupler join two PVC pipes together.
Create a ridge support by joining 2 PVC pipes with a coupler. Run the ridge support under the hoops, then slip each end over the rebar if utilizing the traditional or market garden polytunnel. Make sure to secure the ridge support to the existing hoops using tie wire.
To provide addition support to the frame place a 1X2 horizontally midway between the ground and ridge support. Secure the 1X2 using tie wire at every PVC pipe.

Steps for Raised Beds

Cut the plastic at least 22 feet long. Stretch out the plastic over the hoops.
Next, on both side, roll-up the 2X4 with the bottom end of the plastic, wrapping twice, do this to both ends. Secure the plastic to the 2X4 using the tie wire every 3 feet.
On one side secure the 2X4 to the PVC frame using a 12-inch piece of tie wire to prevent it from moving in the wind.
On the secured side, from ground level to the ridge, secure the plastic to the PVC pipe by loosely wrapping the plastic around the PVC pipe multiple times. Pierce the tie wire through the layers of plastic and around the pipe. The purpose of wrapping the plastic loosely is to prevent the plastic from tearing in a gust of wind. Repeat this step at the opposite end.
On the opening side, use the spring clamps to secure the plastic to the frame.

Steps for a Traditional or Market Garden

Cut the plastic at least 22 feet long. Stretch out the plastic over the hoops.
Next, on both side, roll-up the 2X4 with the bottom end of the plastic, wrapping twice, do this to both ends. Secure the plastic to the 2X4 using the tie wire every 3 feet.
Secure the 2X4s to the frame to prevent it from moving in the wind. Using a 12-inch piece of tie wire secure the 2X4 to each end of the frame on both sides.
At each opening, to prevent the plastic from tearing at the ends, loosely wrap the plastic around the PVC pipe multiple times. Pierce the tie wire rough the layers of plastic and around the pipe. The purpose of wrapping the plastic loosely is to prevent the plastic from tearing in a gust of wind.

A polytunnel greenhouse can be constructed using the same supplies and instructions mentioned above. However, closing the ends will be necessary to provide warmth within the greenhouse. As you can see, how to build your own polytunnel is extremely easy and worthwhile.

DIY Polytunnel for under Forty Dollars