A spacious "room" for plants - greenhouse design

Sunset, March, 1994 by Jim McCausland

It's a plant gallery, nursery, and salad factory

TO EXTEND THEIR GROWING season, gardeners Elva and Doug Watson of Bend, Oregon, built a structure framed more like a conventional room than a standard greenhouse. The 20- by 20-foot greenhouse provides lots of room for plants, and its wood frame is handy for hanging everything from shade-cloth to vegetable support nets.

Besides being used to start seedlings, the greenhouse supplies the family with salad greens well before outdoor crops are ready to harvest, and long after autumn's first killing frost.

The greenhouse was built with standard construction materials, from insulation and plywood to 2-by 8-foot fiberglass glazing panels.

Details are adaptable for almost any greenhouse. To level soil-temperature swings in seedling beds, the Watsons lined each bed with 1-inch blue polystyrene foam insulation. For irrigation, they buried timer-controlled soaker hoses in each bed. A pumice mulch around permanent plants such as strawberries minimizes evaporation. A hose suspended from the ceiling provides extra overhead watering and doesn't kink when stretched.

Hanging plants are suspended from dowels attached to the rafters. At floor level, beds are spaced far enough apart to allow room for a wheelbarrow.