Winter Raspberry Production in an Earth Contact Solar Greenhouse.
The 400 raspberry plants were ordered and delivered. One day was spent planting the bare root plants in 3 gallon plastic pots filled with compost. The plants were set aside on a level area covered with weed barrier in a location sheltered from the wind.
The building site was chosen based on location to other buildings and the amount of dirt accessible. The building site was laid out and marked off. A neighbor was hired to spend 5 days dozing out the Earth Contact Solar Greenhouse (ECSG) footprint and using that dirt to create a bank on the uphill side. The finish work for the excavation was done with a small tractor and bucket.
Used tires were sourced through local tire shops for free. The only requirement was that a statement was signed to certify that the tires were going into a building project. The tire shops needed this documentation to show to the EPA inspectors. One sidewall was cut off using various electric saws. After burning up a reciprocating saw and a circular saw, it was determined that the best option was a jig saw. This was used to remove the sidewalls of the remaining tires. The tires were sorted into similar size categories. Beginning with the larger tires a line was laid in the ECSG footprint along the north wall. The side with the sidewall removed faced upward. The small tractor and bucket were used to scoop dirt into the tires. A tamper was rented to tamp the dirt into and in between the tires. This process was repeated until the tire wall stood 6 foot tall. Each layer was set back from the edge of the layer below to help stabilize the wall. The dirt in the footprint is a heavy clay. The weather has been too dry or too wet to proceed further with the wall construction, at this point.
The 200 Nova primacane raspberry brambles did bloom and produce 10 quarts of raspberries. These large, flavorful, and sweet berries were greatly enjoyed! The production was not at a level that sales were considered this first year.
The results have been the production of raspberries that greatly exceed the products that can be purchased in area grocery stores. This has encouraged us to believe that the end product will be very popular with local chefs and restaurant owners, once production is at a scale that sales will be possible.
Weather proved to be a larger obstacle than was anticipated. Heavy spring rains and a dry summer halted construction. The heavy clay in the selected construction area cannot be worked when more than slightly wet or when extremely dry. The excavation and wall construction has also taken more man hours than anticipated.
Of the 400 raspberry plants ordered, 70 were lost. This is a higher percentage than expected.
Tires have been more readily available than they were believed to be. There appears to be a rather unlimited supply for construction purposes.
Only a jig saw should be used to remove the tire side walls. The circular saw and reciprocating saw that were used quickly died due to the motor burning up. The jig saw is not the most comfortable for the operator, but lasts the longest.
WORK PLAN FOR 2012
The dirt work will need some minor repairs due to the winter weather and run off. Once the soil is ready the tire wall will be completed on the north side. Shorter tire walls will be constructed on either end, and a footer of tires will be constructed on the south side. The topsoil that was scraped off and set to the side will be used to back-fill the ECSG footprint and to cover the berm on the uphill side.
The waterline will be run and the hydrant set up inside the ECSG.
The greenhouse frame and plastic will be used to cover the ECSG footprint. Wooden end walls will be constructed between the shorter tire walls and the frame peak. The entrance and exit will be in the end walls.
Rigging for the raising and lowering of the insulation blanket will be attached to the exterior of the ECSG. The insulation blanket will be permanently mounted to the frame.
If all goes according to schedule, the greenhouse will be completed in time to move the Nova primacane raspberries in before the first frost. Trellis will be placed to help support the plants. The harvest for these plants will be extended to December or January and sales will be made to area restaurants. The Pre-Sale Survey will be disbursed before sales are made.
Once the extended fall season is complete, the remaining 200 Heritage floricane raspberries will be moved in and the Nova primacane raspberries moved back to the weed barrier location. These plants should begin producing in March and sales will once again be made to the restaurants.
Post-Sale Surveys will be conducted near the end of the early spring growing season.
Tours and Outreach will be conducted during the winter and early spring growing season.
The ECSG concept was shared with 20 Lincoln University Farm Outreach Clients and five community members in informal settings. Many found the idea interesting, but no one has pursued construction of a similar structure to date.
No other Outreach or Tours have been done. It was determined that with the poor weather and slow construction the sharing of this idea would prove more beneficial to participants at a later date.
The Tours, Field Days, and Brochure described in the Grant Application will all be completed during the 2012 and early 2013 growing season.