Thanks to beautiful 60-degree weather and help from many participants, we accomplished everything we planned for our November 6-7 permaculture weekend.

Ken Fisher, Mark Hoffman, and Ken Urban building side walls for the cold frame. In this picture, the cold frame door is already attached to the south wall of our center.

Our primary goal was to construct a cold frame/mini greenhouse on the south side of our center. Keeping with the principles learned in our two week permaculture course last July, our design capitalizes on an unused resource by harvesting wintertime solar gain on the south facing wall. We also benefit by the house protecting the cold frame from cold northwest winds. We have planted spinach in the cold frame to be harvested in early spring.

In our climate, small spinach plants can remain dormant during December and January in an unheated but insulated cold frame. In late February, there is enough light and heat to stimulate growth in these young plants, such that by late March, the leaves are large enough to harvest. Normally we cannot plant spinach outdoors by late March, so using the cold frame over winter gives us a very early harvest. However, the best thing about planting in this manner is how daylight length will work to our advantage. In our northern Illinois climate, soil temperature is too cold to plant spinach until around mid April. A mid April planting of spinach will produce until late June, at which time it is no longer harvestable because it bolts and goes to seed. The tendency to bolt is caused by long daylight hours as well as by high outdoor temperatures. These two criteria also apply to spinach over-wintered in the cold frame, meaning the spinach in the cold frame will also bolt in late June. The result is that we can harvest spinach almost two months longer from the cold frame than from the unprotected planting. That's the idea with permaculture – work with growing cycles of nature to maximize abundance.

In keeping with permaculture principles, we decided to use simple materials that we had on hand. The cold frame cover is made of two layers of thin Mylar that was donated by Mark Hoffman's brother Brent. Between the two layers of Mylar are two layers of clear bubble wrap plastic. This simple covering is held inside a 2x4 hinged frame that can easily be opened to access the plants. The total cost for this cold frame was $130, not counting labor donated during the work weekend. We built it to last a minimum of 10 years, putting the average cost at $13/yr. The base utilizes 4x4 landscape timbers that we removed from the perimeter of the original garden at our center. We chose to remove these timbers so that we could reshape the garden into curving beds to encompass the adjacent fruit trees in a manner more consistent with the principles of permaculture.

Bill's strawbale cold frame.

Additionally, we are experimenting with another spinach planting in the main garden that uses straw bales for a base and recycled sliding glass doors placed on top of the straw bales to provide a protected space. The closer door in the photo has been covered with Mylar on the inside to diffuse the light while the glass on the far door has been left unfiltered. Using this approach, we will compare the effects of direct vs. diffused sunlight on young plants in early spring, as well as how this design compares with the cold frame on the south side of the center.

Our permaculture weekend also involved moving many flowering bulbs. Renee Trenda, Carroll English, and Sue Fisher moved bulbs from beds around the building, to circular patterns around trees in the yard. Bulbs (daffodils, tulips, garlic, onions, etc.) are known to repress insect infestations in trees, especially fruit trees. Bulbs planted in this way are also useful as cut flowers or as food, thus serving multiple purposes. This ‘stacking' of functions is a basic premise of permaculture design.

Stop by sometime to see our projects – or better yet, come to our April 2005 open house and we will share a fresh spinach salad!

Ken and Renee enjoying the delicious dinner prepared by Gina Cassidy, one of our weekend guests from Champaign.