I've now got a few months of temperature measurements
from two greenhouses. One is full of water barrels
and the other has double plastic.
It is too early for definite conclusion but here is
what appears to be happening:
1. The center of both greenhouses stays warm. Plants
near the edges have trouble in both greenhouses.
2. Burying the barrels isn't a good idea. More
surface area works better.
3. Big greenhouses may cost less than a small greenhouse
full of barrels and function about the same.
The small greenhouse is 8x16 and has ten 55 gallon barrels
full of water. One of my greenhouse books recommends 6
barrels for this greenhouse or 2-3 gallons of water for
each square foot of covering.
The other greenhouse is 20x40 and about 12 high. It gets
slight less sun but often stays warmer than the small
greenhouse. This was a surprise and i'm now trying
to understand what is happening.
I've just finished reading the revised edition of:
Greenhouse Gardener's Companion
by: Shane Smith
This isn't an organic book but it is full of
useful information. I ignored the herbicide
stuff but did find lots of nuggets. The author
did not like hydroponics and gave some good reasons
to avoid it. The best part was a listing of plants
that can survive year round in a greenhouse. This
is ideal for building sustainable food systems.
Here is a partial list:
onions - surprise, onions can grow year round
and reseed themselves. Bunching onions
and chives are best.
pineapple guava - only the small self fertile types:
(apollo, collidge,nazemetz)
shungiku - edible flower.
chard - withstands both cold and heat.
carrots - another crop that does well in a small
space. Reseeding is possible as is
continuous replanting of tops. Not good
for hot summer greenhouses.
New Zealand spinach, lettuce, Chinese cabbage are
also capable of year round harvest.
fig - easy to grow
bay - soup flavoring
jeff
