DIY Greenhouse Underground

A trench runs down the middle of this DIY greenhouse for any climate.
Courtesy FARM SHOW Magazine
January/February 2014
Add to My MSN

The trench inside this greenhouse forms a heat sink during the day, while concrete block walls release heat at night.
Photo courtesy FARM SHOW Magazine

Content Tools

Dean Steward built a 14-by-24-foot “in-ground” DIY greenhouse for just $120. He simply trenched out a walkway between ground-level beds, walled it with concrete blocks and covered the beds with cattle panels and plastic.

Steward laid out his DIY greenhouse with two 24-by-4-foot beds separated by a 3-foot-wide trench and two waist-high block walls.

“I used a backhoe to dig out the trench and laid the walls without mortar,” says Steward. “I drove rebar into each cell and rammed earth in to fill them. It has been more than a year, and they are holding well.”

He added concrete block steps at one end and built end-walls out of scrap lumber. For the roof, Steward drove in two lines of wood stakes, 10 to a side and 12 feet apart. He fastened 16-foot-long, 50-inch-wide cattle panels between the stakes and covered them with plastic.

“I’m 5 feet 8 inches tall, but with the curve of the cattle panels, I can walk on the beds without hitting my head,” he says.

The trench forms a heat sink during the day, and the concrete block walls soak up heat to release as outside temperatures cool.

For more information on this innovative design, send Dean an email at

Reprinted with permission from FARM SHOW Magazine.

Post a comment below.


6/22/2015 2:13:45 PM
Nicely done. I just finished my cattle panel greenhouse. I didn't do the trench though (way to much work :). It took a better part of a weekend with some good planning and about $300 (not including the shade cloth). I threw up a video if you want to take a look -

10/15/2014 4:15:49 PM
I like this idea. But. I do wish people would post true costs of projects like this. You cannot build this for $120, unless you happen to have most of the materials lying around already and are not counting the cost you already paid for them. 5 cattle panels at $20-26 each, 150' (?) of dimensional lumber, a door or two, greenhouse plastic, 300+ (?) concrete blocks, rebar, hiring a backhoe to dig the trench...

1/22/2014 4:01:01 PM
I need to ask how do you keep the water out and from filling up the trench ? I am very interested in building something close to this....

1/22/2014 9:47:54 AM
25ltr Plastic drums filled with water are a good cheap heat sink and can be used as supports for worktops.

Pay Now & Save 50% Off the Cover Price

First Name: *
Last Name: *
Address: *
City: *
State/Province: *
Zip/Postal Code:*
(* indicates a required item)
Canadian subs: 1 year, (includes postage & GST). Foreign subs: 1 year, . U.S. funds.
Canadian Subscribers - Click Here
Non US and Canadian Subscribers - Click Here

Live The Good Life with Grit!

For more than 125 years, Grit has helped its readers live more prosperously and happily while emphasizing the importance of community and a rural lifestyle tradition. In each bimonthly issue, Grit includes helpful articles, humorous and inspiring articles, captivating photos, gardening and cooking advice, do-it-yourself projects and the practical reader advice you would expect to find in America’s premier rural lifestyle magazine.

Get your guide to living outside the city limits delivered straight to your mailbox. Subscribe to Grit today!  Simply fill in your information below to receive 1 year (6 issues) of Grit for only $19.95!


At Grit, we have a tradition of respecting the land that sustains rural America. That’s why we want you to save money and trees by subscribing to Grit through our automatic renewal savings plan. By paying now with a credit card, you save an additional $5 and get 6 issues of Grit for only $14.95 (USA only).

Or, Bill Me Later and send me one year of Grit for just $19.95!