Category Archives: greenhouses

Building a Cold Frame

Building a cold frame was last weekend’s project at our house and we did it in the nick of time, just before the cold blast of arctic air and many inches of snow hit us this week.

Although we built a winter greens hoop garden a few years ago and it is working to produce winter greens like a charm (see my post about that here), my goal was to do a fall gardening project using the salvaged glass I’d saved years ago to make a cold frame.

Being in town, unfortunately, our neighbor to the south has a lot full of huge overgrown trees which shade our house in the wintertime, therefore my chosen “best” spot site for this mini-greenhouse isn’t perfect, but will get a few hours a day of sunlight on sunny winter days. The spot happens to be sandwiched between the concrete driveway and the house.

First, we took a trip to a neighbor’s dumpster where they are deconstructing part of a house and picked up a couple pieces of wood there, and then, we headed to our fabulous Boulder Resource Center (recycled community materials) to look around. It was a lucky day there, because we found three perfect sized lengths of redwood which ended up being exactly what we needed for the project.

The first photo, below, shows the project in its early stages. Designing the box with the materials at hand was the hardest part and I took a great deal of care and time in the planning stage. To construct it, my husband did the sawing and I got to have fun using the electric screwdriver.

This photo shows the project farther along, with glass in place. Careful measuring has paid off nicely.

Finally, the box is in place. Since this photo was taken, I’ve sunk it’s edges into the ground, found an old thermometer to put inside, and started a few spinach seeds as an experiment. I stacked rows of bricks against the back wall and plan to place a few old milk cartons inside that are filled with water as additional heat sinks. The floor is already covered in small rocks which should also help retain heat for this passive solar mini-greenhouse.

It seems to be pretty well settled that the plastic hoop house works best for growing winter greens in our area and if you think about it, glass conducts cold a lot better than plastic does. Eliot Coleman layers plastic with success in Maine’s cold winters. My project is an experiment and I hope to try a few things but mostly I want it for starting seeds next spring. I already think I should have made it taller so it could house some short tomatoes, but I will work with what I have. The glass panes slide apart nicely to vent it when it gets too hot inside and I will either bring the cold-sensitive seed starts indoors or throw a blanket over the frame on the colder spring nights.

Whew. Got it finished just in time. The total cost was about six bucks for this salvaged-materials project.

NOTE: As I post this, the outdoor temperature is 27F and the cold frame’s thermometer is showing 85F after the sun hit it an hour ago. Later… 100. Wow.


Also recommended, this previous post: Extend Your Growing Season with Simple Backyard Coldframes or Hoop Gardens.

Largest LED Vegetable Growing Factory in the World Opened in Japan in 2014

After the Great Earthquake that Japan experienced in 2011, it has repurposed a Sony Corporation semiconductor factory located in the northeast region’s Miyagi Prefecture and turned it into the world’s largest indoor farm illuminated by LEDs. General Electric reports that they developed the LED fixtures which emit light at wavelengths optimal for plant growth used in the indoor farm.

Another company involved in the project, Mirai Co., based in Tokyo, runs vegetable growing factories. This new growing indoor plant operation is on about 2,300 square meters of land and is able to produce 10,000 heads of lettuce plus other vegetables per day. The produce will be sold to local supermarkets.

The hope is to build more factories similar to this one in other parts of Japan. The LED lights reduce electricity consumption by 40 percent as compared to fluorescent lighting and can use spectrum specific light for optimal growing of the vegetables.

The combined venture further intends to export produce to other nations as well as export the entire growing factory set ups and technology. They have already received requests to do so.


For further information see: http://www.gelighting.com/LightingWeb/apac/news-and-media/press-room/press-releases/2014/Japan%20Case.jsp

3 Picks: France Farmer Suicides, Henlights, Indoor Cropping

Below, are today’s three chosen agricultural-related news picks.

1) Male farmers in France are 20 percent more likely to take their own lives than the rest of the population: A new report says that financial pressures and social isolation are the leading causes. According to figures from France’s National Institute for Statistics and Economic Studies, revenue from farming fell by 23.6 percent between 2007 and 2008 and a further 35.3 percent between 2008 and 2009. Livestock farmers have been hit the worst.

2) Increasing Egg Production On Small Farms: A Solution To The International Food Crisis? By Abigail Wick.In Berlin on September 20-22, the 2013 Thought for Food Global Summit (TFF) convened thought leaders from 25 countries, including venture capitalists, politicians, scientists, entrepreneurs, artists, and university students to address the international food crisis from a wide array of disciplines, with the aim of generating collaborative, actionable strategies to feed the planet. … The winning team, from the University of California at Davis, introduced Henlights. A small, solar-powered LED light designed to be hung in chicken coops, Henlight can be used to stimulate increased egg production during darker winter months, when egg production naturally declines. A technique already use in large-scale egg production, Henlight makes this practice affordable for small-scale and family farms.

3) Optimism About the Future of Indoor Food Production: By Tess Riley. Hydroponics and LED lights used in indoor greenhouses, though the systems are expensive to build, have the potential to greatly increase vegetable yields, and protect plants from unpredictable weather. The increasing use of renewables as heat and energy sources in these systems is the way forward.

BONUS: Photos from Boston Globe’s “Big Picture” on the 2013 harvest from around the world.

This news post was written and compiled by K. McDonald.

Extend Your Growing Season with Simple Backyard Coldframes or Hoop Gardens

“Spring is the time of plans and projects.”
― Leo Tolstoy, Anna Karenina

This one’s for the gardeners. The days are getting longer and we have a renewed hope for spring, that annual rebirth, the guarantee for a brand new growing season. Yesterday I already heard the first of the season’s Red Winged Blackbirds singing along South Boulder Creek. The Sandhill Cranes will be appearing in Nebraska shortly to fatten up on their way to Siberia, and the gardening catalogues are rolling in, too.

Serious gardeners itch for ways to extend the season both in the early spring and in the late fall. Here’s hoping that some of the photos below will serve to inspire you to take on a project to extend the season in your own space.

Here where I live in plant hardiness Zone 5 in Colorado, we raise greens for all but three months of the year in our backyard, and our seasonal extension comes from adding a four by six foot hoop garden bed. Our hoop garden is located under an evergreen tree which takes advantage of the sun’s angle in the off season for growing, and is shaded in the summertime. By locating it in such a spot we are not only extending the growing season, we have extended the available precious growing space available in the yard.

Don’t forget to know your seeds. By planting greens with the best cold tolerance, you can extend your season even more. Some seeds worth considering are spinach, mache, arugula, chard, claytonia, radish, winter lettuce mixes, italian dandelion, and mizuna.

Below, is a collection of photos of other gardener’s projects meant to inspire you to come up with a design that works well in your space…….

In this first photo, a hoop garden greenhouse was built to fit over an existing raised garden bed.

Next, here is a tidy cold frame made from corrugated plastic and a wooden frame benefiting from the thermal solar collection of the brick wall behind it. Thermal heat can be improved by adding plastic gallon milk jugs filled with water against the back wall of the coldframe, too.

This classic cold frame is located on the protected and sunny south side of a house using wood and plastic as materials.

Here someone has utilized an urban front yard space to grow a garden containing a simple A-frame plastic greenhouse. The small photo to the right shows an inner detail of that same greenhouse space showing us that the frame is constructed with strong bamboo posts.

This simple project was done by a boy with just plastic and left over bricks. The family will be able to reclaim the space easily for their summer garden.

This gardener used jars as mini-greenhouses to start seeds. The setup extended the season just slightly for lettuces grown on a protected bench behind a house.

The photo below shows us what appears to be the gardening space of a very serious Chicago gardener. Multiple growing beds are covered with spun polyester garden fabric and black plastic mulch is covering spaces between the beds.

For those desiring something bigger, here’s a simple, small backyard greenhouse that was a d.i.y. project using plastic and a wood frame with a corrugated plastic roof. (It looks like it needs a spot protected from the wind.)

Finally, this busy grower utilized indoor windows to the maximum, to start tomatoes early in recycled plastic food containers.