Earth Sheltered Hugelkulture Greenhouse

Hello Permie Friends,
I have so appreciated all of the great ideas, links, images and creative works in process shared throughout this forum.

My contribution is a combination of various ideas. I have a few 15x7x8 all fiberglass greenhouses in the mountains right outside of Sandpoint Idaho.  I really like the simplicity and sturdiness of arch greenhouses, as well as the increased refraction of light. My original plan was to use standard raised beds of imported soil, as my acidic soil is not conducive for growing much. The day that the soil was to be delivered, straight line winds came through and blew my greenhouses as if they were tumbleweeds.  One ended up five feet off the ground upturned in some shrubbery and another rolled down the road onto my neighbor's road. Both ended up with structural damage but essentially still functional so I decided that a change of plans was in order. Thus began the earth sheltered hugelkulture greenhouse project that is still very much a work in process.

With an excavator, we dug down 2-3 feet and added 8 inches of river rock as a base. This was to deter rodents as well as allowing aeration and reducing the potential for flooding in the spring.  On top of this I put 1/4 inch hardware wire along the sides. Gophers are crazy destructive on my property so multiple layers of defense are necessary.  The wire also helped to hold the layer of peat added next, and the soil, from being devoured by the river rock foundation.

On top of a thick layer of peat I put pine logs and sticks in various experimental arrangements for the hugelkulture beds.  I places pit run locally purchased soil (cheapest bulk soil that leaves in rocks of all sizes) which was mixed with compost. I also added clumps of kelp and volcanic minerals and saturated everything as I slowly built the system up.  Also included was purchased untreated hardwood charcoal fermented in human urine to help neutralize the pit run and compost mix that was on the acidic side, and to also provide the good bacteria biochar effect. At the top I planted drip hose for watering and hope to have several rain catching water towers.

My hope is to use this system year round and to have a strong perennial and herbal plant representation. On the peat path, I sprinkled herbal lawn seed that includes creeping thyme and chamomile. I would love to hear comments, suggestions and consideration from this highly informed community.

More photos that didn't upload?

Ready for planting...

Outside view