Big Ideas for Food
Bicycle Powered Salad Spinner
This was an entry in the 2007 Specialized “Innovate or Die” contest. A great example of one of our many creative student projects! We still use a washing machine to spin our salad greens but have gone back to electric power. In the winter, we do use a large 5 gallon hand-spun washing drum for small batches.
Hoop Houses and Green Houses
The following information is provided by Dr. Carol Miles as part of her Vegetable Research Program.
With proper crop and variety selection, there are many vegetables that can be produced during the winter in Washington. In central and eastern Washington, cold protection is needed for most vegetable crops while in western Washington, hardy crops can be grown without cold protection while half-hardy crops do best with protection (Table 1). When you have selected a particular crop to grow during the winter, it will be necessary to then select a variety that is cold tolerant. Refer to seed catalogs for specific variety information.
Table 1. Classification of vegetable crops according to their adaptation to field temperatures (Source: Knott’s Handbook).
Row Cover. The two most common materials used for cold protection are fabric rowcovers and clear plastic. Fabric rowcovers come in different weights and can increase day temperatures by 4-8° F. Lighter fabric rowcovers (0.45–0.55 oz./sq.yd) are generally promoted as insect barriers and are not recommended for winter use. Heavier fabric rowcovers (0.9–1.5 oz./sq.yd) are used for frost protection. Place rowcover over metal or PVC hoops to form a cloche (Figure 1). If you live in an area that receives freezing temperatures, do not place rowcover directly on top of plants as frost damage can occur where the fabric comes into contact with the plant. It is important to note that night temperatures under a cloche tend to be equal to outside temperatures.
Hoophouse. Unheated and unlit hoophouses can be an inexpensive means of extending the growing season throughout the winter. Hoophouses are meant to be 4-season structures and depending on the snow load and wind velocity in your area, they may need extra supports. When it comes to construction, it pays to read before you start to build.
Unheated and unlit greenhouses are most effective in the fall and spring but with proper crop selection they can also produce a crop during the coldest months. Use greenhouse-grade plastic to construct your hoophouse for best light and temperature effects. Day temperatures under greenhouse grade clear plastic (6 ml) can be 10-20° F greater as compared to outside temperatures on a clear, sunny day however night temperatures tend to be equal to outside temperatures.
High Tunnels. Most high tunnels are designed as 3-season structures and are not meant to remain covered during snowfall events or during high winds.
Hoophouse and High Tunnel
Portable Field Hoophouse, WSU Extension Bulletin EB1825 (html)
The Hoophouse Handbook. 2003. Growing for Market. 60pp.
Greenhouse Resources for Small Scale Producers, WSU and OSU Small Farms Team