Written from the Eastern Great Lakes areas of North America where tunnels are seen as a route to sustainable farming.
Seeking to extend the growing season and make more crops possible for farmers to grow and sell to local outlets University extension workers have done fantastic work on high tunnel growing systems. Local communities are now reaping a rich and diverse harvest from all that work both in terms of farm incomes, a wave of genuine enthusiasm for local fresh produce, a better understanding of where food comes from and technical know-how.Successful research projects range from high tech field scale systems for covered cherry production at MSU and Cornell, through work on berries and flowers to some wonderful “Community Supported Agriculture” or CSA projects.
CSA type projects are working in both rural areas and cities, not least those such as Detroit, now suffering from a contracting automotive industry. USDA’s Natural Resources Conservation Service (NRCS) has been inspired to offer financial assistance for some New York State farmers to establish seasonal high tunnel systems for crops (http://blogs.cornell.edu/hightunnels/).
Adam Montri of Michigan State University has been lighting up winter grower meetings with his enthusiasm for ‘hoop house’ horticulture. Adam, like many American horticultural extension specialists also runs his own farm in partnership with his wife, growing a wide range of fruit, vegetables and flowers. To find out more visit Adam’s blog http://hoophouse.msu.edu/blog/index.php
Adam has perfected a technique for growing leaf salads right through the Michigan winter without supplemental heating. Inside a “four season” tunnel and under a layer of row cover (fleece) the crops continue to grow for a monthly cutting cycle despite icy conditions outside. Recent measurements for a similar system managed by Cornell scientists showed that a soil temperature of 33°F (1°C) was maintained under the fleece despite outdoor temperatures down to -9°F (-23°C).
Whereas in Britain growers are more familiar with using terms like “Three Season” to describe the useful life of the polythene films used to cover tunnels and hoop houses the Americans use the same terms to differentiate between types of tunnels. “Four Season” tunnels are those that remain clad through the whole year – Spring, Summer, Autumn (Fall) and Winter. These tunnels are strengthened to withstand snow. With 20” (50cm) of wet snow falling in 24 hrs at several sites during February this extra cost is vital. Field scale tunnels are normally built as “Three Season” structures being de-skinned before heavy snow is expected. This ‘time of’ is actually quite useful for many crops – providing the required rest period for berry and cherry crops, some additional spider mite suppression and cleansing of the soil where unwanted salts have built up during the growing season.
Get growing!
