This system is particularly appealing to new-entry growers who want to grow high value crops and who utilize retail marketing channels. High Tunnel Systems High tunnels are not conventional greenhouses. There is no permanent heating system although it is advisable to have a standby portable propane unit to protect against unexpected below-freezing temperatures. There are no electrical connections. The only external connection is a water supply for trickle irrigation.
Ventilation is provided by installing roll-up sides .
An 8 to 10-inch baseboard is attached to the posts at the soil surface. A hipboard is attached to the bows 36 to 42 inches above the baseboard. At the bottom edge of the plastic, which should initially extend at least a foot beyond the baseboard, a one-inch metal pipe is laid along the edge of the plastic exactly parallel to the tunnel. The edge of the plastic is taped every 12 to 18 inches with duct tape to the pipe which is then rolled to the edge of the tunnel alongside the baseboard. With a sliding T-handle at one end of the pipe on each side of the tunnel, the plastic may be rolled to any height up to the hipboard.