Season extension is typically the first step market gardeners take to increase productivity. On my farm, the garden production will be kept simple for the first year but that doesn’t stop brainstorming future innovations.

Aquaponics has always fascinated me. Being a very low input system, the fish feed the plants and can in turn feed me or be processed into fish meal which is the most expensive part of the chicken ration. Chickens can also be directly integrated by using their litter to feed composting worms, which in turn can feed the fish. So if economics ever shifted that placed higher commercial value on tilapia than the chicken, the model can easily be scaled to place fish into the lead role the aquaponics model.

Unfortunately winters here in the Shenandoah Valley, and the rest of Virginia west of the tidewater region, can be harsh. Any economic gain from aquaponics is quickly negated by energy expenditure to provide heat to keep the fish healthy.

Recently, my friend Brauck shared some innovative gardening practices. Plans for a $300 Underground Greenhouse that produces year-round sent the wheels in my head into motion.

The gist of the plans are to dig wide trench 6-8 feet deep in a southern-exposed location, pile the removed earth on the north side of the trench, and seal the trench with transparent greenhouse plastic. A visual representation is pulled from the link above:

Using geothermal energy (thermal mass of the earth) to regulate temperatures while adding trapped solar energy give such potential to this design. Even in winter a tiny solar arrangement could supply power to pumps. If this arrangement provides a stable enough environment while reducing or eliminating energy needed for heat, aquaponics may move from fantasy to viable to profitable.