Low tunnels.  The metal hoops that you see are covered with clear plastic during the colder months of the year.  This creates a greenhouse-like environment that allows us to grow flowers, like ranunculus and anemones, which otherwise won't survive our winter temperatures and winds.  By adding a second layer of protection, in the form of frost fabric, we are able to create an environment within the tunnels that is two to three zones (in terms of USDA growing zones) warmer.  So instead of being limited to plants that can withstand winters in USDA Zone 7a, where we are located, we can grow plants that normally require Zone 9 temperatures!  As great as these low tunnels are, they are a LOT of work, both to set up and maintain, so we have a bit of a love/hate relationship with them.  If you want to read more about our adventures with these tunnels, you may be interested in our blog called Tunnel Vision.