and more flexibility on crop rotation without ever having to bother to dig the soil out of a stationary house (or use soil steam sterilization) to cure greenhouse soil sickness. A US Department of Agriculture program is helping farmers install polytunnels. The program was announced at the US White House garden in December 2009. Farmers in Iraq are building these in increasing number and adding drip irrigation to grow tomatoes. References External links . 11 December 2009 by . Polytunnels on Hortweek 1 November 2016 Polytunnels: Second generation on Hortweek 13 February 2015 Polytunnels - Fresh Produce on Hortweek 6 November 2015 Agricultural buildings Greenhouses Horticulture Portable buildings and shelters