Simple Plastic Tunnel Cold Frame or Row Cover

March 3rd, 2009 by David LaFerney Leave a reply »
This plastic tunnel is being used inside of the greenhouse to protect tender plants against a late hard freeze - very effectively I might add.

This plastic tunnel is being used inside of the greenhouse to protect tender plants against a late hard freeze - very effectively I might add.

A simple plastic tunnel like this can serve as a cold frame to grow salad greens  all winter long, to grow out tomatoes and other tender plants, to extend the season for an early Spring start or a late Fall harvest, or even as a screen house to keep birds off of your strawberries or vine borer moths off of your squashes.  You can also use one of these to dry out water logged beds and warm up the soil so that you can begin planting  in early Spring. These devices are so useful, cheap, easy, and quick to build that everyone should have at least one – it’s almost as good as having your own polytunnel greenhouse.

materials for plastic tunnel row cover

materials for plastic tunnel row cover

Materials:

  • 5-5′ lengths of 3/4″ (inside diameter) polyethylene water pipe
  • 10 – 1/2″ x 1/2″ x 14″ wooden stakes
  • 1 – 12′ x 6′ x 4 mil clear plastic sheet
  • 4 – 1/2″ x 1 1/2″ x 8′ wood strips
  • staples and nails.

As usual you can (and should) substitute materials that you have available on hand.  You can use anything for stakes that are strong enough to drive into the ground and will slip inside of the rib pipes. You can use a broom stick, piece of pipe or any long thin objects for the poles, and you can fasten the plastic skin to the poles with duct tape instead of staples.  Clearly almost any kind of bendable pipe can be used for the ribs, but here’s a tip – contractors or plumbers are likely to have a scrap collection of one kind of plastic pipe or another that comes in coils that they will either give away or sell incredibly cheap – just ask.  In the worst case, you can usually buy cut lengths at the home improvement or hardware store.

This design is also great for hardening off.  The cover can be opened or closed in about a minute by one person.  The whole thing can be moved to a new location and set up in 15 minutes.

This design is also great for hardening off. The cover can be opened or closed in about a minute by one person. The whole thing can be moved to a new location and set up in 15 minutes.

Start by cutting your parts to size – this tunnel will cover an area that is from about 2 – 3  feet wide and the black pipe for the ribs are 5′ long, and the plastic is about a foot and a half wider – you can roll up any excess plastic on the poles so it is better for it to be too wide than too narrow.  In this case I made the poles shorter than the plastic so that the excess could be used to close up the ends, but you could also make the poles the same length as the plastic and use rectangles of plywood or other sheet lumber to close up the ends.  Use your imagination.

Once you have your parts cut to size fasten the poles to each long edge of the plastic sheet.  I used staples to do this, and then rolled the plastic around one piece of wood and fastened another strip to it so that the plastic is sandwiched between the wood pieces.  If you are just using tape, then you will want to wrap the plastic around the pole and tape the plastic sheet back to itself forming a tube with the pole inside – tip: construction tape (duct or housewrap tape) sticks very well to plastic, and not very well to wood – don’t try to tape to the wood other than as a temporary measure.

Once you have that done, roll the plastic up around one of the staves until you are ready to deploy it.

The ribs just slip over the stakes - you can probably get by with ribs that are much further apart than this if you want.

The ribs just slip over the stakes - you can probably get by with ribs that are much further apart than this if you want.

In the garden, simply drive the stakes into the ground where you want them, and slip the pipes for the ribs over them.  Since my ribs are made out of coiled pipe they already have the right shape, if you used straight sections of pipe you might need to use something more robust than 1/2″ wooden stakes to hold against the tension of the polytunnel ribs.

Now just roll your plastic out over the ribs and there you have it.  If you experience a lot of wind you might need to weight down the plastic a bit, but under normal conditions the wooden pole will probably do the trick.  When you need to get into the pollytunnel you just lift a pole and lay it over the top – almost as easy as a regular cold frame, but a lot easier to build or move.

Now would be a good time to build one!

Advertisement

22 comments

  1. Keep onn working, great job!

    Here is my web page: seo Hemel Hempstead

  2. I love what you guys are up too. This sort of clever work and
    reporting! Keep up the great works guys I’ve included you guys to our blogroll.

    My web page :: search engine optimization

  3. Anna says:

    Hello, :

    Nice to contact you.we are plastic agriculture mulch film manufacture in Qingdao China.
    and exported mulch film to France market
    Our products including:
    garden tunnel cover, black plastic mulch film, tomato tube film, clear film with 1cm holes.
    garden greenhouse film. poly tunnel kit.

    We supply to Japan and France supermarket, all the packing can be in PE hanger bag and with
    colourful paper logo.

    .
    If interested to us,welcome to your inquiry.

    Sincerely
    Anna

  4. Gisella Patharkar says:

    Just what I was looking for. I like to overwinter a big lemongrass plant and also protect some of my cacti/prickly pears from winter moisture and frost.

  5. GW says:

    Tip: use short pieces of blades from mini blinds under each staple, so the plastic won’t tear, when nailing or stapling plastic sheeting to wood. Or sandwich it between two boards with screws after a wrap.

  6. Heather says:

    Exactly what I was looking for! Thanks!

  7. jabberay says:

    Simple and effective. I’ve also made similar but used rebar for the stakes, they don’t break as easily and should out last the wooden stakes.

  8. Great blog! It gave me new insights about gardening. Thanks for sharing.

  9. scranton mma says:

    thanks for posting this. I ve been looking for step by step plans and this seems very simple and easy to do.

  10. pat Callahan says:

    the preceeding is spam in turkish. please delete.

  11. Günümüzün modern toplumuna ula?mada en etkili reklam arac? olan aç?khava mecralar?, 24 saat reklam imkan? ile firmalara hedef bölgeler belirleme; ürünlerini, hizmetlerini bu bölgelere yo?unla?t?rma imkan? sa?lar. Kapsam alan? geni?, görsel ve yarat?c? bir aç?khava reklam? daha fazla farkedilmenizi sa?lar ve kuvvetli bir marka etkisi olu?turur.
    reklam

  12. Katie says:

    Coleman also recommends using bags filled with sand to hold the edges and ends down. Adds great security from wind and easy to move when need to get into the tunnel. A row cover fabric can be used instead of the plastic and left on all summer without the threat of over heating–keeps out deer and bugs too!

  13. pimapen says:

    THat is such a great idea!!

  14. shawn says:

    If you use heavy guage wire instead of the pvc, you put a small loop in each “leg” of the hoop, approx 12in from the ends. Put these wire ribs in, push until the loops are at ground level. Bury the windward side. String cord through the loops, and run from rib 1 over your cover to the next rib on the other side, alternating as you go. This should be snug, not nec. Guitar-string tight!

    I think you’ll find this will keep your tunnels grounded even during major winds.

    It’s a recommendation I picked up from either Eliot Coleman or the victory garden…

  15. Sandra says:

    I am in a very windy location (hilltop ~where the valley wind picks up speed and comes roaring up to)

    Do you have anything you’d suggest to insure a tunnel stays landborne ?
    Thanks for any ideas.

    • David LaFerney says:

      Just use heavier “sticks” for the plastic, and don’t leave any openings for the wind to get under there and lift it up. Your garden might benefit greatly from a hedge or other structure to divert the wind somewhat.

  16. margaret cunningham says:

    when fixing our telephone line, the engineers in their wisdom left behind black tubing like what you have pictured here…of course i was steamed at having to clean up their mess, but decided to keep the rather long length of it thinking it might come in handy for something…so glad i did now!!!

Leave a Reply

*