Non-electric micro greenhouse heater

greenhouse peppers

My peppers have recovered beautifully from the last 20 degree freeze in their new micro-greenhouse. Now I am preparing to keep them alive as winter progresses with likely much deeper freezes.

new heater pic 1

I kept my peppers alive a couple of weeks ago during the 20 freezes by using a heat lamp. But it is my preference to find off-grid solutions that are also inexpensive. I have used kerosene lamps before for this purpose but they tend to deposit soot on the plastic which is a problem to clean off, and kerosene is expensive. This year I am going to try these home made flower pot heaters. They should provide comparable heat to a kerosene lamp (at least the larger size I am making) but should be less expensive to operate and the soot should remain inside the pot.

new heater pic

There are several problems with the standard directions for these pots. One is the tea light candles most frequently recommended for this. Their burn time is just not long enough to get through the night. I don’t know about you, but I really don’t want to go out on a cold, cold night to switch them out with new ones. So I wanted to be able to use much larger, longer burning candles that also don’t cost a fortune. My solution is to use home-made, multi-wick candles using shortening or lard or other rendered fat from the homestead as a fuel (will make another post specifically on that). But to use this, I needed a deeper base that can hold them safely under the pots.

This leads into problem number 2 most commonly associated with this. Some use bread pans which are deeper but unstable. Another person screwed on the base which looked really nice, but would require more time and effort to screw off to put in new candles, especially if you are using something larger than the standard tea lights recommended for this. And his base was way too shallow for anything bigger than tea lights. I solved this problem by finding a clay square shaped pot that the larger pot (10″ can comfortably rest on) and the smaller 8″ pot can snugly fit inside, making a very stable and secure fit. The corners provide opening for oxygen to feed the candles so that I do not have to worry about any spacers. And the base is heavy enough to not be tippy when the heavy pots are fitted on top.

 lifting pot from base

I used a 6″ carriage bolt to hold the two pots together. It also allowed me to create a nice little handle so that I can easily lift the pots from the base.

Materials I used for creating my pot heaters

1 10″ clay pot

1 8″ clay pot

1 9″x4″ square clay pot for base

1 6″x1/2″ carriage bolt

(could be wider, the holes in these pots are closer to 3/4″ but this is what I had)

At least 2 2″x1/2″ washers (larger holes if you use wider bolts)

8 1″ (or 2″) x 1/2″ washers (again, should be sized to fit the bolt used)

9 1/2″ nuts (or sized to fit bolt used)

I first screw on a nut to the carriage bolt, but not all the way to leave enough to easily grab. I then slide on a 2 inch washer and then 10″ pot.

pot handle

Inside the pot I slid in a 2″ washer and then screw in tightly another nut.

pot washer nut

I then slide in another washer before sliding on the 8″ pot.

I  two pots together

I then alternate washers and nuts to fill the remaining length of bolt. It is my understanding that the purpose of this is to provide more thermal mass and store more heat. Not all pot heater directions, however, include this and a shorter bolt and fewer nuts and washers could be used.

I do not have grandiose expectations with this heater. It certainly is not a high btu device. But it is my hope that it is comparable to a kerosene lamp and will be enough to keep my peppers from freezing in their very small greenhouse. If we are expecting very low teens or single digit lows, I will probably put blankets over the greenhouses. But after my experience with the last freeze, I know a heat source is necessary. The black water barrels should help. But it is my hope that this simple and inexpensive device should provide an extra edge. We will see…

Putting up greenhouses within the shade house

shade house gate


We screwed 2″x3″ boards to support the center of a transparent greenhouse tarp to the center of each section of the shade house. My plan is to leave these tarps permanently screwed in, but to roll up the sides during the warm season and tie the rolls to the center boards supporting the tarp on the ceiling. The sides of the tarp are supported by electrical conduit, forming an arch. The frame of the shade house provides structure to support and put tension on these conduit pipes that it isn’t necessary to attach them to the sides. I just shoved the ends into the soil next to the framed sides of each section, and tied the center joint (required two pipes connected for each support) to the center board that is holding the center of the tarp to the ceiling. The beauty of this method is that the tarp is not damaged with additional holes, and the shade house frame and pvc provides plenty of support and protection from high winds. The shade cloth is still in place, and was reinforced enough last year to be able to handle the small amounts of snow and ice we typically receive. The shade cloth will keep snow and ice off the tarp, protecting the greenhouse.


I attached an old tarp on the back side (north) of the shade house.


And I hung a clear tarp on the south side, to enclose the greenhouse and allow entry.

These greenhouses will not be enough to protect my peppers and more sensitive warm season plants. But they will help heat the garden during the day and retain some heat at night. I am planning to add black water barrels, Hot compost grow beds, mini-greenhouses inside the big greenhouse with thermal mass, and other strategies to keep my more temperature sensitive plants alive and well through winter. I am very pleased with how this simple and relatively inexpensive addition dramatically increases the versatility and value of the shade house. The shade house has by far, proven to be the best and most efficient garden investment I have made in our extreme climate.

Here is a link for a page describing how to build hot bed cold frames:

Raised bed micro-greenhouse


We had our first freeze of the season last week where we had several days of sub-freezing temperatures dipping down to 20. I worked hard to keep some of my peppers and tomatoes alive by using heat lamps and covering them with standard tarps. Peppers and tomatoes are perennial if they are protected from frost and freezing temperatures. And I have learned through experience, that if I am able to keep them alive over winter, they start to produce much earlier, and far more heavily in the spring  than new transplants. And because the period of time between the last frost and 100 degree days of summer is relatively short, it is important to get as much production as early as possible in the spring. Though we have a very long season of frost free days, we actually have only two very short prime growing seasons, in the spring and fall. Only the most heat loving plants continue to produce in summer (winter squash, sweet potatoes and southern peas).


I ordered this from

I have been needing to order these transparent tarps, but for financial reasons, I had to wait. I finally received them yesterday. Now that I have the tarps, I am putting together a more practical and sustainable (and hopefully non-electric) strategy to keep these more vulnerable plants alive during our hardest freezes.


I first placed two black barrels I purchased at a local feed store for $20 each, on each end of the bed. I then filled them with water and closed the lids. These barrels will absorb heat during the day and radiate it back at night, moderating the temperature inside the greenhouse. They also should help to prevent overheating during hotter days.


clip 3

My hoops for the garden bed uses 1/2 inch electrical conduit (cheaper and includes UV protection, a quality standard pvc does not have). For the hoop house clips, I cut 3/4 inch conduit.


To make clips, I first make two cuts down the length of the tube using the chop saw. I lower the blade, cut through the plastic, but not too deep, then slowly pull the pipe towards myself so that the saw cuts to the end. I then make a second cut doing the same thing. Because the tarp is heavy-weight, it is better to have the cuts further apart so that the clip is not too snug and wont tear the plastic when putting on or taking off.

cut clip 2

I then make two cuts, cutting two clips from the initial cuts down the pipe.

cut clip 1


In the event this is not adequate to protect the peppers when it gets really cold. I have a couple more ideas to add. One is to put the peppers in Wall-O-Waters.


Another option I will also be using during the coldest nights is this extra large  clay pot heater. It should be able to do what a kerosene lamp can in heat output, but without the soot and for far less cost in fuel. And I can use home-made candles made from rendered fat from the homestead.

new heater pic 1

Cobbing a wood stove


This is the second time I have cobbed around a wood stove. I have learned a lot after the first attempt. Last time, I used clay and sand from our property. It took a lot of effort and time to dig it up and mix it. I also chopped my own straw. It all was a huge, time-consuming job.

This time, I am using ‘screenings’ from a nearby quarry which is a perfect mix of clay and sand. It also is considered a waste material for them, so was inexpensive for me. And I am using already chopped straw sold for covering grass seed which I purchased at Tractor Supply. What took me weeks to accomplish last time, has taken only a couple days this time. So it does make a huge difference having the basic materials ready and prepared.


The advantage of cob around a wood stove, is that it acts as thermal storage. Wood stoves are either sweltering hot, or the house quickly loses heat as the fire dies down. The cob holds a significant portion of the heat and slowly releases it over time. It is better to have an over-sized stove when using cob, because it won’t provide as much intense heat. But then, the room temperature is more stable over time.


This time around, I am imbedding dense rocks in the cob right next to the stove. They have a much higher heat storage capacity than the cob itself, and it is my hope that they will further increase the heat retentive property of the cob.



I also elevated the stove on bricks to make it a more comfortable height if someone wants to cook on it. And I put a vent passage underneath so that cool air from the floor can be drawn under the stove, up along the back where it is heated, and then vented out. This will be a self-powered system through a natural thermo-siphon.


My daughter helping out. She loves cobbing!

I have learned from experience, that it is better to heat the stove right away after cobbing. If you wait to let the cob dry, it will likely not be fully dry anyway deep inside when you finally do start a fire in the stove, and it will smell very *nasty*! This time around, we are starting fires right away. There is more cracking. But I am fixing those as they appear. Meanwhile, at least it doesn’t stink as the cob steams off with the heat.

Also, I got the stove used off of craigslist. What I like about this particular model, Princess Blaze King, (the same model I used the first time I cobbed around a wood stove), is that it is double walled, and the cob will in no way effect the efficiency of the stove. Some people will leave a narrow gap between the cob and the stove. I chose not to do this because it would end up catching small objects and dust, which possibly could pose a fire hazard, and be difficult to keep clean. I have not had any problems at all with our first stove, by having it completely imbedded in the cob.

The vent that will be behind the stove, will be screened in order to keep anything from falling inside.


Pictures of other cob surrounded wood stoves I have found on the web:

Hugelkulture swales



We don’t have heavy earthmoving equipment, and with our sandy soil, periods of long drought and intense heat and then torrential rains, holding any water on surface for extended periods is difficult and swales can easily be washed away and filled with sand over time. My alternative solution is to build swales out of hugelkulture mounds. I am placing them on contour, digging a trench, but rather than leaving it open (which would eventually fill with sand), I am filling the trench with rotting logs I pick up from along the country roads. Then my daughter is dumping the manure from the animal stalls on top of the wood mounds. I am planting fruit trees on the uphill side, and will plant more drought resistant legumous fodder trees on the down hill side. On top of the mounds, since they will be rich in nitrogen (and the wood should hold moisture), I plan to plant winter squash in the summer. These swales will catch the water, as well as organic matter being washed down slope. The rotting wood will hold that moisture for months, unlike a sandy swale alone. And the trees will have access to that moisture as well as the nutrients both from the swale itself as it decomposes and what is washed down and trapped by the swale. I am also mineralizing these swales and inoculating them with fungi to promote tree growth and systematic long term remineralization of the soil.