My client has decided that he wants a practical, easy to manage greenhouse that is also aesthetically pleasing. Because the greenhouse is going to be on his hotel property, he would like something nicer than a simple, plastic grow tunnel.
Yesterday I started reading Four-Seasons Harvest, by Eliot Coleman–to get some ideas and spark my imagination. Based on what I’ve learned so far, our best bet is to build a greenhouse geared toward extending the harvest season, rather than the growing season.
Growing season extension will require pumping in additional heat, a means of heat collection, heat storage, artificial grow lights and added layers of insulation; all of this can end up being pretty costly, and its management is definitely not “easy.”
Harvest Season extension is much more practical, simple, and costs less. –When extending the growing season, essentially you are fighting against the forces of nature. However, there is no reason to continue to grow heat-loving crops during the middle of winter, when there are just as many crops suited for cooler temperatures.
When extending the harvest season, artificial lighting and complicated means of temperature control are not neccessary; extended harvest can easily be achieved through the use of cold frames, high r-value plastics, and the residual heat of soil mass. *These things alone are enough to create an inexpensive, protected micro-climate for hardy winter vegetables–which can be planted outside during late summer and early fall and then moved into the greenhouse to be harvested throughout winter.
Some hardy winter vegetables include: Arugula, escarole, carrots, chickory, endives, onions, sorrel, and parsely.
The greenhouse can also be used store root vegetables (harvested in the fall) throughout the winter. This can be achieved by creating miniature root cellars. One way of doing this is to bury metal garbage cans with insulated lids in the floor of the greenhouse (the lids should be flush with the floor, and the rest of the can beneath the ground). *Fill the cans with bags of root vegetables which you will be able to pull and eat from throughout the long winter months.
Root vegetables which store well include: Potatoes, beets, radishes, rutabagas, parsnip, and carrots.
Building for an extended harvest season is definitely the best way to meet my client’s desire for a simple and easy to manage greenhouse. After I determine the best location for the greenhouse, I will begin the design phase–keeping in mind the recycled building materials (0ld windows and doors) I have at my disposal.