Concerning plastic barrels:: I have bought greenhouse plastic from Northern
Greenhouse Sales of Neche ND. In their cheerful catalog they claim to plant
vining crops in full barrels down the center of hoophouses. If you want to
start seedlings Jeff, this may not work for you. No matter what the theory
I fail to see how half submerged water barrels will transfer much heat
into the ground. With a compost thermometer one could try different set ups
and measure. Before freeze up I framed the base for a 12 by 20 hoophouse
and unloaded a pickup of cow manure compost into it. When inspired this
winter I plan to cover it and try a row of half barrels down the center
in early spring.
The most ingenious greenhouse system I have ever read about is that of a
Joseph Orr of Laramie , Wyoming, in May 78 Mother Earth News. His was a
hot air collector that blew heat into wet earth heat storage below the
greenhouse. It is an active system but the major components of the hot
air collector , fans , foam insulation, pvc pipe , and the earth which was
there to begin with were not overly exspensive considering the results;
tomatoes and tropicals yearround in Laramie with no other heat. (Yes he did
use electricity but as I understand fans are not particularly energy
gluttons.) This system would not be needed in your balmy climate, Jeff,
but for those of us with over a foot of snow and likely facing at least 2
more months of the same it is attractive.
I plan a 14 by 20 shed greenhouse on the sw side of my living room.
Presently the area is sloped but averages 5 feet below living room floor
level so that construction would start with an insulated perimiter
foundation and then infilling with planting beds, heat storage,
watertanks, rockwork to bring it up to desired levels. I am considering
the above system and or a masonry system like used in the earliest New
England colonial greenhouses . However, my woodshop takes priority this
year and I only hope to start on the foundation to make more level sunny
gardening space. vann
