When constructing a hoop house, one has to consider location, materials, and overall plan.
LOCATION:
Southern facing, southern facing, southern facing! Southern facing beds receive the most sun throughout the day, as the sun moves from East to West through the Southern half of the sky. Thus, the bed should lie horizontally from East to West.
Shadows! Ideally you should try to avoid shadows cast by neighboring buildings--as a tip you can mark the ground with chalk or some other means when the sun is low behind the structure in question. This is absolutely essential if the garden area is already partially shaded (though you should shoot for placement that has full sun).
MATERIALS:
You can construct raised beds from plywood, mortar bricks (a less attractive but easier to construct option), rocks, or other found materials. For Parker's garden, especially as we hope it will be more permanent, the beds will be framed with plywood.
The bottom of the bed should be open but you can lay a plastic layer on the edges to protect the wood from rotting/water damage. A permeable membrane can even be put on the bottom to protect concrete (if the bed is to be located on a patio, etc.)
To promote drainage gravel can be layered on the bottom of the bed, however make sure to increased the height of the bed accordingly.
The soil you put into the bed should be nutrient rich to support crop success, thus compost is essential. Every year, as the soil in raised beds is isolated from the ground (and thus the process of natural soil enrichment) more compost will have to be tilled into the soil.
For the hoop houses:
PVC creates the basic form for the hoop houses. Durable and pliable, the PVC easily establishes a frame.
Plastic is then pulled like a tarp over the frame to create this simple greenhouse.
Watch this youtube video for further instruction:
http://www.youtube.com/watch?v=efQYpzNJOiE&feature=related
