Low Tunnel Growing

Cole_Robbie · December 10, 2015

Does anyone grow in low tunnels, or at least start in the spring under them? I am thinking about building one or two next spring.

I'm looking at this bender:
http://shop.hoopbenders.net/cropprotectionrowcover.aspx

What I have not yet decided on is whether or not I need the purlin bar down the center. The cheapest design would be just the hoops, like this one: http://countyrailfarm.com/2013/03/04...tunnel-bender/

I am thinking at the moment that I will run a 2x4 baseboard down one side and screw the plastic to that board with smaller boards. And then the other side can be held down with sandbags. When I need to get to the plants, I can pull the plastic from under the sand bags, but the board attachment will keep it from all flying away if it is windy. I will probably make plywood ends to the tunnels. On a sunny day, both ends will be open, anyway. Plywood seems easy.

I have a lot of early, compact, determinate cherry varieties that I think would fit in the tunnel. I know for sure that Terrenzo would be perfect, if I wanted to buy hybrid seed. I have grown that variety before, and I like it. It's DTM is in the 50's. My goal would be to have early cherry tomatoes to sell at the farmer's market, alongside my high tunnel tomatoes.

The low tunnel is a cheaper way to grow under plastic. I think it will work, as long as I choose the right varieties. I have a soil that tends to make giant plants, so varieties that a seed company calls "compact" still get 7' tall. I've grown Terrenzo in 10" hanging baskets, bit in my soil it gets much bigger, occupying about a cubic yard of space.

FarmerShawn · December 11, 2015

I made my quickhoop bender out of a scrap of 2X10 lumber. I cut an arc, then routed a groove on the curve to hold and support the pipe (half-inch conduit) as I bend it. A strap screwed on one end holds the pipe while I bend. Also, I found that pvc conduit cut into 18" lengths, sharpened on one end, driven into the ground 10" or so make nice ground posts for the hoops to slide into - much easier than trying to push the hoops into the ground. I just hold the plastic down with firewood on both sides. That way I can access either side equally inconveniently. So far I have only used them at the end of the season to keep peppers, leeks, and Brussels sprouts going long past first frost.

Worth1 · December 11, 2015

This is why I want a tubing roller.
Any pipe any size any radius.

Worth

PhilaGardener · December 11, 2015

I have a low tunnel made from PVC bent into an arc - because it is on a 4ft wide raised bed, they all came out very even. Covered with a remnant piece of 4 mil greenhouse plastic. You can find these cheaply on web sites that sell the material to others - ends of rolls are inexpensive but watch shipping costs. I should probably tie in a ridge pole for stability in wind and snow, but it is in a protected spot. Great for lettuce and a variety of greens.

I really want a high tunnel so I can walk in on a cold winter day!

How do folks solve the issue of ventilation of low tunnels on sunny days? The small size means it heats up quickly in the sun, and I am not available to cover/uncover all day long. Does anyone have a good solution to this issue?

Marcus1 · December 11, 2015

I use low tunnels on some of my watermelon and cantaloupe. I use #9(3/16") wire for the hoops, they are placed every 6'. I bought the hoops pre-formed from Marvels Plastic. I cover the hoops with 76" clear perforated plastic and cover the edges and ends with dirt. The extra heat and wind protection early make about a 2-3 week difference in days to harvest. I leave the tunnels on till the first blossoms set then remove them. The dirt on the edges pulls the plastic tight so there is no need for a purlin. We get very strong winds here on the front range and the tunnels have survived well. With the perforated plastic I have seen very little cooking of the plants and don't open the ends because if the wind gets under the cover it's headed to the next county in the blink of an eye.
Marcus

clkeiper · December 11, 2015

I do low tunnels but with poly cover not greenhouse plastic. I start tomatoes and zucchini in them in april (which is about 4-6 weeks before you can plant out here) and trench the edges under with dirt shovels on it after one of us tightens the cover the other shovels a little dirt on it all the way down the row. BUT if you get a freeze you may as well start over with the tomatoes. They will not come through it and produce well. They may survive, but they dont thrive.
We bought wire hoops for the tunnel from Yoder's. 64" spring steel hoops for 100/$33.00 and we reuse them every year. They are great to protect many a crop. Some from bugs, some from dirt... like lettuce, and for the cold or for shade. We don't limit using them to extending the season.

AKmark · December 12, 2015

A good friend of mine is the master at using row cover to start plants under to get a jump start on the season. I have also used these on a smaller scale for corn, which does not like the cold Alaskan soil.
Anyway, I think starting tomatoes under these then taking off plastic after the ground has warmed, will affect seasonal yields by increasing length of the season, just like any other crop.
Irt covers the row, then plastic on hoops over that, about 3ft wide or so, not as tall, tension wire hoops work great, and they are super cheap, just buy a roll of wire and cut it.
You will have to use drip irrigation, or something of like to water though, at least until you pull the plastic cover off. Here's a decent example I found online.
http://edis.ifas.ufl.edu/cv201

Redbaron · December 12, 2015

Quote:

Originally Posted by PhilaGardener

I have a low tunnel made from PVC bent into an arc - because it is on a 4ft wide raised bed, they all came out very even. Covered with a remnant piece of 4 mil greenhouse plastic. You can find these cheaply on web sites that sell the material to others - ends of rolls are inexpensive but watch shipping costs. I should probably tie in a ridge pole for stability in wind and snow, but it is in a protected spot. Great for lettuce and a variety of greens.

I really want a high tunnel so I can walk in on a cold winter day!

How do folks solve the issue of ventilation of low tunnels on sunny days? The small size means it heats up quickly in the sun, and I am not available to cover/uncover all day long. Does anyone have a good solution to this issue?

Use row cover instead of 4 mil greenhouse plastic.

Cole_Robbie · December 12, 2015

Thanks for all the replies.

I saw that Harris sells slitted row cover:
https://www.harrisseeds.com/storefro...d-6-x-250.aspx

They also sell a punched hole row cover:
https://www.harrisseeds.com/storefro...d-6-x-250.aspx

I have no idea which of the two products would be better for tomatoes. Maybe slitted, so the plants don't get wet on a cold rainy day?

AlittleSalt · December 13, 2015

Just a thought:

Make the tunnels look more like a long house. It doesn't matter how tall you choose to make it, but I'll use these measurements as an example. Put in 4' stakes down the middle of your row then 2.5' stakes down each side a foot or so away. Run a nylon string on top of the length of the 4' stakes and do the on the same on the 2.5' stakes. At the bottom of the outer 2.5' stakes, run more nylon string. Throw plastic or whatever you like on this and secure the bottom to the nylon string with clothespins - or whatever you come up with. That way when global changes happen - you can open up the lower part to get some air.

If I were to build a lower tunnel - that's my initial thoughts.

FarmerShawn · December 13, 2015

Quote:

Originally Posted by AlittleSalt

Just a thought:

Make the tunnels look more like a long house. It doesn't matter how tall you choose to make it, but I'll use these measurements as an example. Put in 4' stakes down the middle of your row then 2.5' stakes down each side a foot or so away. Run a nylon string on top of the length of the 4' stakes and do the on the same on the 2.5' stakes. At the bottom of the outer 2.5' stakes, run more nylon string. Throw plastic or whatever you like on this and secure the bottom to the nylon string with clothespins - or whatever you come up with. That way when global changes happen - you can open up the lower part to get some air.

If I were to build a lower tunnel - that's my initial thoughts.

Cool idea, but here's one concern. If it rains, water will pool in the sags between the horizontal strings, getting heavier and heavier until the whole thing comes crashing down. Or, if you catch it in time you slit the plastic strategically so the pooling water drains. Don't ask me why I feel this might be a concern...
I have learned that a single string across the peak of my low hoops works best.

Gerardo · December 13, 2015

It's getting cold here and I'll need to protect my winter children. keep the ideas coming please.

I've never really looked for it specifically, but does Lowe's or HD carry any material that could work?

Cole_Robbie · December 13, 2015

They sell construction plastic, with no UV inhibitor. I priced it, and it's not much cheaper than getting a UV-protected greenhouse type plastic.

Worth1 · December 13, 2015

Quote:

Originally Posted by Cole_Robbie

They sell construction plastic, with no UV inhibitor. I priced it, and it's not much cheaper than getting a UV-protected greenhouse type plastic.

That and vapor barrier but you get one seasons of use out of it and you better get rid of it or you will have a mess on your hands.
It will break up into smaller and smaller flakes just like the garbage floating around in the ocean.
Worth

Fred Hempel · December 13, 2015

Check out the extent of growing under plastic in El Ejido Spain. The whole region is covered in plastic.

Yes. All the white is plastic.

December 10, 2015	#1
Cole_Robbie Tomatovillian™ Join Date: Jun 2012 Location: Illinois, zone 6 Posts: 8,407	Low Tunnel Growing Does anyone grow in low tunnels, or at least start in the spring under them? I am thinking about building one or two next spring. I'm looking at this bender: http://shop.hoopbenders.net/cropprotectionrowcover.aspx What I have not yet decided on is whether or not I need the purlin bar down the center. The cheapest design would be just the hoops, like this one: http://countyrailfarm.com/2013/03/04...tunnel-bender/ I am thinking at the moment that I will run a 2x4 baseboard down one side and screw the plastic to that board with smaller boards. And then the other side can be held down with sandbags. When I need to get to the plants, I can pull the plastic from under the sand bags, but the board attachment will keep it from all flying away if it is windy. I will probably make plywood ends to the tunnels. On a sunny day, both ends will be open, anyway. Plywood seems easy. I have a lot of early, compact, determinate cherry varieties that I think would fit in the tunnel. I know for sure that Terrenzo would be perfect, if I wanted to buy hybrid seed. I have grown that variety before, and I like it. It's DTM is in the 50's. My goal would be to have early cherry tomatoes to sell at the farmer's market, alongside my high tunnel tomatoes. The low tunnel is a cheaper way to grow under plastic. I think it will work, as long as I choose the right varieties. I have a soil that tends to make giant plants, so varieties that a seed company calls "compact" still get 7' tall. I've grown Terrenzo in 10" hanging baskets, bit in my soil it gets much bigger, occupying about a cubic yard of space.

December 11, 2015	#2
FarmerShawn Tomatovillian™ Join Date: Dec 2011 Location: Vermont Posts: 1,001	I made my quickhoop bender out of a scrap of 2X10 lumber. I cut an arc, then routed a groove on the curve to hold and support the pipe (half-inch conduit) as I bend it. A strap screwed on one end holds the pipe while I bend. Also, I found that pvc conduit cut into 18" lengths, sharpened on one end, driven into the ground 10" or so make nice ground posts for the hoops to slide into - much easier than trying to push the hoops into the ground. I just hold the plastic down with firewood on both sides. That way I can access either side equally inconveniently. So far I have only used them at the end of the season to keep peppers, leeks, and Brussels sprouts going long past first frost. __________________ "Red meat is NOT bad for you. Now blue-green meat, THAT'S bad for you!" -- Tommy Smothers

December 11, 2015	#6
clkeiper Tomatovillian™ Join Date: Nov 2011 Location: ohio Posts: 4,350	I do low tunnels but with poly cover not greenhouse plastic. I start tomatoes and zucchini in them in april (which is about 4-6 weeks before you can plant out here) and trench the edges under with dirt shovels on it after one of us tightens the cover the other shovels a little dirt on it all the way down the row. BUT if you get a freeze you may as well start over with the tomatoes. They will not come through it and produce well. They may survive, but they dont thrive. We bought wire hoops for the tunnel from Yoder's. 64" spring steel hoops for 100/$33.00 and we reuse them every year. They are great to protect many a crop. Some from bugs, some from dirt... like lettuce, and for the cold or for shade. We don't limit using them to extending the season. __________________ carolyn k Last edited by clkeiper; December 11, 2015 at 07:25 PM.

December 11, 2015	#3
Worth1 Tomatovillian™ Join Date: Feb 2006 Location: Den of Drunken Fools Posts: 38,539	This is why I want a tubing roller. Any pipe any size any radius. Worth

December 11, 2015	#4
PhilaGardener Tomatovillian™ Join Date: Jan 2014 Location: Near Philadelphia, PA Posts: 1,940	I have a low tunnel made from PVC bent into an arc - because it is on a 4ft wide raised bed, they all came out very even. Covered with a remnant piece of 4 mil greenhouse plastic. You can find these cheaply on web sites that sell the material to others - ends of rolls are inexpensive but watch shipping costs. I should probably tie in a ridge pole for stability in wind and snow, but it is in a protected spot. Great for lettuce and a variety of greens. I really want a high tunnel so I can walk in on a cold winter day! How do folks solve the issue of ventilation of low tunnels on sunny days? The small size means it heats up quickly in the sun, and I am not available to cover/uncover all day long. Does anyone have a good solution to this issue?

December 11, 2015	#5
Marcus1 Tomatovillian™ Join Date: Jan 2013 Location: Colorado Posts: 124	I use low tunnels on some of my watermelon and cantaloupe. I use #9(3/16") wire for the hoops, they are placed every 6'. I bought the hoops pre-formed from Marvels Plastic. I cover the hoops with 76" clear perforated plastic and cover the edges and ends with dirt. The extra heat and wind protection early make about a 2-3 week difference in days to harvest. I leave the tunnels on till the first blossoms set then remove them. The dirt on the edges pulls the plastic tight so there is no need for a purlin. We get very strong winds here on the front range and the tunnels have survived well. With the perforated plastic I have seen very little cooking of the plants and don't open the ends because if the wind gets under the cover it's headed to the next county in the blink of an eye. Marcus

December 12, 2015	#7
AKmark Tomatovillian™ Join Date: Jun 2013 Location: Wasilla Alaska Posts: 2,010	A good friend of mine is the master at using row cover to start plants under to get a jump start on the season. I have also used these on a smaller scale for corn, which does not like the cold Alaskan soil. Anyway, I think starting tomatoes under these then taking off plastic after the ground has warmed, will affect seasonal yields by increasing length of the season, just like any other crop. Irt covers the row, then plastic on hoops over that, about 3ft wide or so, not as tall, tension wire hoops work great, and they are super cheap, just buy a roll of wire and cut it. You will have to use drip irrigation, or something of like to water though, at least until you pull the plastic cover off. Here's a decent example I found online. http://edis.ifas.ufl.edu/cv201

December 13, 2015	#10
AlittleSalt BANNED FOR LIFE Join Date: May 2014 Posts: 13,333	Just a thought: Make the tunnels look more like a long house. It doesn't matter how tall you choose to make it, but I'll use these measurements as an example. Put in 4' stakes down the middle of your row then 2.5' stakes down each side a foot or so away. Run a nylon string on top of the length of the 4' stakes and do the on the same on the 2.5' stakes. At the bottom of the outer 2.5' stakes, run more nylon string. Throw plastic or whatever you like on this and secure the bottom to the nylon string with clothespins - or whatever you come up with. That way when global changes happen - you can open up the lower part to get some air. If I were to build a lower tunnel - that's my initial thoughts.

December 13, 2015	#12
Gerardo Tomatovillian™ Join Date: Feb 2015 Location: San Diego-Tijuana Posts: 2,594	It's getting cold here and I'll need to protect my winter children. keep the ideas coming please. I've never really looked for it specifically, but does Lowe's or HD carry any material that could work?

December 13, 2015	#15
Fred Hempel Tomatovillian™ Join Date: Dec 2010 Location: Sunol, CA Posts: 2,723	Check out the extent of growing under plastic in El Ejido Spain. The whole region is covered in plastic. Yes. All the white is plastic.