Healthy soil and sustainable growing

[Dan Conine <dconine@bertramwireless.com>]

Farmtek also has some plastic tubes that you can fill with water, if the 
barrels take up too much space. I want to try this sometime, but I have 
a pellet/corn stove to warm the greenhouse in spring, and it doesn't 
cost much to operate.
Cinder blocks painted black can store a lot of heat, also. Rocks, 
bricks, whatever dense stuff you have. Pile it up where the sun can warm 
it, insulate the pile from contact with the walls.

Dan
Belgium,WI