Hügelkultur - Heated Greenhouse Build - Warming the Soil

This is definitely what I would call an experiment in winter vegetable growing. I had an idea of circulating warm air underneath the topsoil in order to keep the ground temperature up even if only a few degrees. I did not go too extreme as this is just a test and I am only running it in the two long beds off each side of the center row. This is where I will be growing most of my tomatoes and I have reserved some space in the very middle row as a sort of control group to see if warming the ground has any noticeable effects on the production. The middle row will not have any of my heating tubes underneath the soil.

One day, if I can pull off this career shift at 50, I will be building GeoThermal greenhouses. For now we'll call this a pseudo geothermal at best.

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I wrote in a previous blog about how I have designed my raised/sunken beds so I will not be going into all that detail but please check it out here: Raised/Sunken Beds - My Spin on Hügelkultur

After I prepared the beds using the method from the previous post I dug down just a couple more inches to make a place for the corrugated tubing to lay. I am using 4" solid tubing (without holes); you will see below I did cut some holes to counter any condensation build up.

Next I laid the tubing in

Then I added in my two layers of both wood chips and stump grindings

I brought the first layer of wood chips up to the top of the tubing

Then added the second layer of stump grindings

I continued this all the way down the end of the row and then added on the layer of hay

I am going to have one continuous section of tubing with one end of it drawing warm air from around the wood furnace that I will be building in the future and the other simply venting back out into the greenhouse. All of my beds extend about a foot past where the greenhouse end walls will be as I plan to extend both ends of the greenhouse so in a couple years I should have just a little over 2,600 square feet of climate controlled growing.

Being that the beds go out a little further I decided to connect the two sections of tubing outside of where the greenhouse wall will be at this time. I went ahead and dug it down about 18-20 inches thinking this will help combat any heat loss. This will all have another thick layer of wood chips on top of it as well as I plan to boarder the entire greenhouse with them.

I did make several notches in the bottom of the tubing as I stated before to let any water that condensates wick out into the ground. The beds do have a very subtle grade to them so I did not put any holes in the tubing in those areas. I only did this in the trench as any condensation buildup would make it's way there eventually.

And now all I have is the 2 ends sticking out of the ground

Before I sealed up the ends with some cloth to ensure no debris would fall in while I begin construction on the greenhouse itself I did do a test and while I could not make it sound exactly like the Horn of Helm Hammerhand I did see a couple Uruk-hai scurry off into the woods.

I am really hoping my topsoil has dried enough so that I can continue to get it all sifted and back on the beds. I only have 4 more days off before I have to get back to making other people's houses look beautiful so I hope the weather forecast holds true and I can at least get the skeleton up and all the beds and walkways to full completion by then.

This is likely the most exciting project I have ever taken on and I really look forward to sharing my progress with you all. Please follow along if you'd like and please leave me a comment if you decide to do so.

Go Get Dirty!