Field prep

It’s official we are planting field crops this year- summer & winter squash, beets & carrots, potatoes and possibly sweet potatoes. The seedlings were started a few weeks ago and the area cleared. The plot will run the length of the south side, 100′ x 12′.

Dirt Hugger just arrived with 12 yards of compost. Tyler, with his daughter as co-pilot and their dog Tele as look out, skillfully dumped the load down the hundred foot runway.

Lucky for us our neighbor Angel just bought a tiller attachment for her tractor and was happy to come by and work it in before the forecasted rain.

It was a beautiful spring day perfect for working outside. I’m thrilled to go ti sleep dreaming of summer squash bursting from neat tidy rows!

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Casa Verde Growbeds

By creating a sort of “reservoir” under the soil modeled after earth boxes, our plants can take up as much water as they want, when they want it.

Hard to believe, but the natural occurrence of rain falling from above is not always ideal. If it comes at the wrong time, or in too much quantity, it can cause molds, inhibit pollination, and actually creates conditions that are not ideal for plants to uptake water.

Plants have a hard time extracting water and nutrients from saturated soil because there are no air pockets. From here there are 3 levels of water uptake that plants notice. They can easily uptake from the coarse soil material, when the easy pickins are gone, they start uptaking from finer soil particles, but this is a little more difficult for them. Finally, they are left with only very fine soil particles with water left in them, and while this water is difficult for the plant to extract, they will not die. In nature plants may see all four the these conditions in transition. During a heavy rainfall they get saturated and must wait for that to drain, and then transition through the 3 stages.

What our growboxes provide for the plant is all four conditions…at the same time, so that they can always grow at their maximum potential. The bottom is saturated as it is literally in the water reservoir. Water wicks up, and it creates a moisture gradient ending with dry soil on the surface, creating a natural evaporation barrier. Plants will generally set as deep of roots as necessary for their optimal uptake, and our 24 inch deep beds accomodate most of our veggies, and allow for us to practice bio-intensive farming.

Design Details

Our beds are 20 ft x 5 ft, and 2 ft deep and made of 2 inch lumber. They are lined with 45 mil rubber, and the ends are plumbed with custom bulkhead fittings.

Once rubber is in and the ends are sealed, a layer of pumice rock lines the bottom.

Over the pumice, we put a layer of landscaping cloth which allows water transfer, but keeps the soil separate from the pumice. We created a custom cross-section of pumice that always allows a pocket of air under the soil, even when the reservoir if full (the high peak down the center is higher than the water line). And low points ensure that the soil is in contact with the water down to 1 inch of water.

Nutrient rich water from our aquaponics system is pumped into one end of the bed, and the water comes out clear on the other end. The reservoir is now full, and soil will wick up water feeding the veggies.

Featherweight Freightrain

It turns out that our greenhouse has roughly 3000 lbs of air inside of it. That’s right, light as air…air.

One key for keeping plants happy in a greenhouse is keeping that 3000 lbs of air in constant motion. Luckily, it’s like a freightrain, in that once it’s moving it doesn’t take a lot of energy to keep it moving. So with the installation of four 12 inch fans, we now have an invisible 3000 lb train making laps around the greenhouse.

This freightrain has many benefits. The main importance is keeping high/low temperature and humidity pockets from forming microclimates within the greenhouse, helping prevent mold and foliar disease. It also transports freshly exhaled oxygen away from the plants and replaces it with CO2.

Our four small fans spaced about 50 ft apart keep the air moving between 50-100 ft/min, it’s not fast, but it makes for more pleasant environment for the plants (and humans too).

30,000 ft view

The Big Picture

Feeding 100 families from an average size city plot starts with a grand vision, one dreamt up over a year’s worth of researching, volunteering, and planning. Meet Moria Reynolds, Casa Verde founder and visionary.
The big idea? Fish are raised in tanks inside the greenhouse, which in turn provide nutrient-rich water for the plants. The greenhouse is packed with “earth-box” style raised beds which are plumbed to have the warm, nutrient-laden water bottom watering the plants. Before entering the grow beds, the water is pumped up and flows through troughs overhead where heat loving plants are growing in containers of soil or aquaponic style. Rainwater collection keeps the tanks topped off and solar heating provides warm water for the system. Mushrooms living amongst the veggies provide CO2 and soil nutrients, worms keep the soil fresh and recycled as they live within the beds as well. The fish eat food that the greenhouse produces as well!; plants, worms, and fly larvae. Biomass gets reprocessed in compost bins lining the outer walls, helping to insulate against the cold in winter. There is no weeding as everything is grown in raised beds, there is no watering as the bottom watering keeps the soil moist. Ultimately, solar panels provide the electricity needs, with the final goal being a zero input ecosystem (except for some elbow grease, seeds, and love).