Imagine enjoying 75 degree temperatures, earthy spring smells and home-grown tomatoes long after everything else has gone by and the temperatures hover at 40 degrees. You can get more growing days—if not weeks—by building a hoop house to get plants going and keep them going in the shoulder seasons of early spring and late fall.  “You are essentially putting up a miniature greenhouse over a garden plot,” says Andy Radin, a Research Associate and Ag Extension Agent for the Plant Science and Entomology department. You can buy a kit, or you can head to your nearest home improvement store to get most of the materials.

Materials:

  • 10 x 20-foot garden bed
  • 10 4-foot pieces of rebar, concrete reinforcement bar
  • 2 2-foot pieces of rebar
  • 7 10-foot foot pieces of ½-inch schedule 40 PVC pipe, cut into 22-inch lengths (10 22-inch pieces)
  • 2 50-foot lengths of very strong twine or thin rope
  • 2 6-foot lengths of rope
  • 20 8-inch zip ties
  • 32 x 15-foot piece of greenhouse-grade plastic sheeting (available online)
  • 10 Large binder clips (available from office stores)

To build:

Drive the 4-foot lengths of rebar 2 feet into the ground in two parallel lines about 8 feet apart. Within each row, the posts should be about 5 feet apart.

Slip a 22-inch sleeve of PVC pipe over each one of the rebar posts. Use the 10-foot lengths as tunnel hoops by slipping one end over the remaining 2 inches of rebar projecting above each sleeve and then bending it over to the corresponding rebar in the other line of posts. It will take some strong bending in order to prong it onto the post. The highest point of the hoop should be about 5 feet.

Take a zip-tie down to the base of the rebar posts and loop it around. Slip another zip-tie into the loop you just made, but don’t cinch it tight. You are creating one in a series of loops that serve as anchor points for the structure that will keep the plastic roof and walls in place. Make loops at the base of all ten posts.

Take two 2-foot rebar posts and pound them into the ground about 5 feet out from either end of your hoop house, and tipped back at an angle from the structure. Leave 6 inches showing, and put something luminous on the end, like paint, so you can see them.

Take a piece of cord or twine and tie it to one of those ends. Loop it around the first PVC pipe arch at the highest point in the center. Continue looping it around each of the five arches. Secure it to the second rebar stake at the opposite end, with no slack. You are creating a ridge pole to prevent sagging.

Drape your plastic sheeting over the arches and center rope beam.

To secure the plastic sheeting, take one of the 50-foot lengths of rope and knot it around the zip-tie at one end of your hoop house. Thread it over the hoop and around the zip-tie on the second post on the opposite side. Continue staggering the rope in a zig-zag pattern until you reach the other end of the hoop house. Take the second 50-foot length of rope and stagger in the opposite direction to create a crisscross over the center line. This is like lacing up a shoe.

Gather the excess plastic sheeting on the ends and bunch together, and bind with one of the 6-foot lengths of rope.

To let out excess heat, roll the plastic inward (to prevent rain from accumulating and weighing it down). Secure the roll-up on each side by clamping the roll tightly with binder clips, five on each side. Roll it down to keep the heat in. Keeping the roll-ups in place may take some trial and error, but persist!

Voila! Private greenhouse for $75 and an hour of your time.