Perpetual Green Gardens - (406) 219-1445 -
Copyright (c) 2012 Perpetual Green Gardens, LLC.  All rights reserved.          

Earth-powered greeenhouses greatly enchanced growing climate without any use of fossil fuels, expensive technologies, or even electricity.

In fridged Montana, this serves to nearly triple the growing season from 120 frost free days to 300.  This also results in a zone 8 growing space in a zone 4 climate.  This enables things like figs, peaches, pears, appricotts, pinneapple guavas, persimmons, nectarines and much more to be grown in a cold, arid mountain climate like Bozeman, MT.


Natural systems are employed to meet all of the needs of the greenhouse.

Several feet into the ground, the earth maintains a consistent 40-60 degree temperature range.  This stable temperature (a freely available, natural resource) is tapped into as heat for the greenhouse.  The earth temperature not only provides heat during the winter but also helps cool the greenhouse in the summer.

Passive solar and geothermal provide all of the heating, cooling and ventilation. 

This is a time tested solution for growing in cold climates.  Heat activated venting arms, coupled with earth tubes, provide passive ventilation for the greenhouse.  When the sun heats the greenhouse, these fluid filled arms expand, opening vents along the ridge of the greenhouse.  As hot air escapes, the negative pressure inside triggers a thermo-syphon, pushing hot air out of the greenhouse and drawing fresh, thermoregulated air in through the earth tubes.


Earthtubes add another level of climate buffereing to the structure.

Earth tubes are used to pipe outside air several feet underground before it enters the greenhouse.  During the summer months this pre-cools the outside air.  During the winter it preheats it.  These systems are simple, dependable, and cost nearly nothing to operate.

Rainwater catchment is a key component to our systems.

Tanks are sized according to the roof's loading potential, local climate variables, and the water needs of the greenhouse.  Settling tanks and first flush diverters are employed to preserve the purity of the water.

Using Earth Bag building, our greenhouses can be built for a fraction of both the economic and environmental costs of conventional methods.

Earth, compacted in bags, is used instead of concrete.  This technique converts the excavation dirt into the foundation for the greenhouse, using little more than bags and human power.  The earth bags are then stuccoed with a thin coat of morter to preserve and protect them.  This technique keeps more money circulating in the community, creating jobs, while also reducing the use of energy intensive, manufactured materials.

Get started growing delicious healthy food in harmony with nature.

Even in the cold mountain climates we love to live and play in, fresh fruit from your own back yard is a reality.  Imagination is the only limit.


Earth Powered


Designed to benefit from and maximize the geological and physical principles of the earth and sun.