After years of tinkering with existing low tunnel designs and making various modifications, we've developed a low tunnel custom designed for use with both recycled auto tire and corrugated sheet metal beds. The low tunnel will provide the gardener with a versatile, user-friendly means of protecting and enhancing the growth of crops growing in permanent raised beds.

The basic components of this low tunnel are hoops made from PVC pipe, a polyethylene greenhouse film cover and hold-down straps made from 1/4-inch rope. The tunnel cover is held in place using rope straps located between each hoop. The straps enable the user to raise and lower the cover without unfastening or fastening the cover every time the tunnel is opened or closed.

Begin tunnel construction by fabricating hoop receptacles from 1-inch schedule 40 PVC pipe. When attached to the side of beds, the receptacles hold the hoops in an upright position.

Building Materials Needed to Construct One Mini Tunnel to Cover a 40-Inch by 30-Foot Recycled Auto Tire or Corrugated Sheet Metal Raised Bed Quantity Item Description Unit Price Total 200 feet 1/4-inch nylon rope $0.08/ft $16.00 1,8-ft by 38-ft sheet 6-mil greenhouse poly film $0.13/sq ft $39.52 80 foot 1/2-inch sch 40 PVC pipe $0.22/ft $17.60 20 foot 1-inch sch 40 PVC pipe $0.44/ft $8.80 44 2-inch wood screw $0.05 $2.20 2 3/8-inch by 2-foot rebar $0.75 $1.50 2 Eye screw $0.50 $1.00 *Prices may vary depending on location, etc. Total $86.62