This is the last installment on the hoophouse for bareroots. Though its primary purpose was to jump start the bareroot fruit trees and lilacs, there will be room for some of the other trees and shrubs we order bareroot then grow out for a year or two (or more). Growing bareroot stock lets us offer plants at a more affordable price. Shipping on container grown plants is incredibly expensive, and the minimums that must be ordered are usually far beyond what our little nursery can consider.
So--to recap, pvc pipe is looped under the four inches of compost that the potted trees are sitting on. Wink is doing the final hookups on the fittings that will carry heated glycerine through the looped pipes, then return it to the reservoir in a closed loop.
Aly is screwing down the pump in the photo. Behind it are the intake and outtake lines that carry glycerine to and from the solar heater. Wink's hand is on the solar panel controller--it runs the pump.
This photo shows the heater and solar panels outside the hoophouse. They face due south so get the most sun that can be had from a fixed system. Piping coiled inside the heater carries the glycerine that absorbs heat from the sun, then gets pumped under the floor of the hoophouse. (Previous blogs show the heater interior being plumbed)
In the next shot Wink is pouring the glycerine into the reservoir. The freezing point of glycerine is -31, so the pipes will be safe from freezing unless we have a snap like the one last winter. Since the system runs off solar panels, it won't be operating at night when we'd be most likely to experience that kind of cold. If it gets that cold in the daytime, I give up!
The last shot shows the glycerine returning to the reservoir. It worked!!!
The breakdown on the hoophouse: we spent about $400 on the 2" white pvc, $85 on wood, $150 on the white plastic cover material, and about $100 on the groundcover fabric (less than a third of a $400 roll). That's about $735--pretty good when you consider we buy the aluminum hoophouses for about $1200--not including wood, plastic cover, or groundcover.
The heating systems adds about $450 to that. The 45 watt solar panel kit (includes the 12 volt dc charge controller) was on sale at Harbor Freight for $145. The 12 volt rv water pump was $99. The 5 gallons of glycerine (ordered online) was $85 plus shipping. Assorted fittings and clamps added about $25. We had the solar heater (salvaged) but the black flex irrigation pvc we used inside was about $100.
So the total cost was under $1200. Not bad to protect thousands of dollars worth of plants, year after year.
We're happy to answer any questions--go to the Mountain Gardens facebook page, or email.