In summer 2011, with only ~25 plants in the ground, I watered each plant by hand with a hose. Unfortunately, the nearest well (Well #2 on the map) was >100’ away and the hose path was right under the heaviest vehicle, wheelbarrow, and foot traffic.
So I usually used one of the hose bibs on the irrigation line fed by Well #3 in the orchard—that’s a minimum of 200’ of hose just to reach the EFG, plus up to 150’ more to maneuver within it. Not elegant, not efficient, but it worked OK given the small number of plants and all the other, more immediate, tasks we faced.
In winter 2012, I planted ~75 more small trees and shrubs (with digging help!) in the EFG, so summer irrigation would be much more challenging. I didn’t yet want to install a permanent system of drip lines or sprinklers because so much of the area is still unplanted—no groundcovers and low perennials are in yet—and I don’t want to have to spend money and time on something that will have to be modified or torn out. But I also didn’t want to schlep hundreds of feet of hose around, particularly with faucets a couple hundred feet away. So with the help of our water guru Hazen Parsons, we installed a solar-powered irrigation system that lightens my workload and still provides flexibility for the future.
First, we overhauled the pumping part of the system. I decided we would use Well #2—the one that supplied the house before we installed the rainwater collection system. It was housed in the ugly tin shack on the left of this photo (behind the remains of the original shed),
Then we pulled the pump out of the well.
It functioned fine using grid electricity, but I wanted to be as independent of the grid as possible. We replaced it with a submersible pump powered by the two 80W south-facing solar panels.
The panels pump slowly—1.5 to 2 gallons per minute. However, they work whenever the sun shines on them, which in our dry summer is pretty much all day. In the course of a day, the system pumps 800 to 900 gallons. The water goes to this 1,200-gallon tank on the north side of the barn,
which was installed by Hazen and crew in June 2012.
The tank is only a few feet off the ground, so there isn’t enough water pressure to drive an irrigation system. We needed a second, "booster" unit to pump water from the tank to the forest garden. I looked into solar, but I would have needed eight 80W panels to get enough pressure—too much cash and space. So ours is powered by grid electricity. It pumps water through a 1” PVC irrigation system
that serves four hose bibs (elevated faucets) at key locations in the forest garden. I used short hose runs and raised sprinklers
to water not only the trees and shrubs, but also the buckwheat cover crop that I sowed in the intervening areas.
It worked out well, and I’ll use the same techniques next summer and maybe in 2014. By 2015, I’ll have planted groundcovers and low perennials everywhere, and will need some sort of permanent sprinkler system. Not sure what it will be yet, but I can easily connect it to the existing system.
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