A cable trellis can be used to support both large and small vines.

How to Build a Cable Trellis

by Brian Barth

Designing with vines in the landscape is an opportunity to create something both beautiful and functional. Most vines can cover a lot of territory in a short time, so they are good choice for making a quick screen to obstruct an unpleasant view. However, unlike a hedge, you have to provide something for the vines to grow on. They can be trained to an existing fence or arbor, or a trellis can be constructed specifically for the purpose. Steel cable is a sleek, modern material to work with when planning a trellis, disappearing quickly into the foliage during the growing season and making a bold architectural statement in winter.

1 Dig two holes for the posts that will support the trellis cables 8 feet apart. These should be about 2 feet deep and 8 to 10 inches in diameter. Set your posts in the holes and mix a batch of concrete. You will need a helper to hold the posts upright as you fill the holes with concrete around each of the posts. While the concrete is still wet and workable, rotate the posts so their sides are parallel to each other and use a level to make sure they are perfectly vertical. The posts will become the frame on which you will attach the cables. Allow the concrete to cure for 24 hours before continuing.

2 Check with a line level to see if the top of the two posts are perfectly level with each other. If not, use a reciprocating saw to cut off a portion of the taller post so the tops are level. Use a carpenter's square to mark the posts so your cut comes out nice and straight.

3 Mount the 2-by-6-inch boards to the top of the two posts using 3/8-inch lag screws. Center the boards on the posts so they extend an equal distance beyond each one. You are making a frame that resembles the "pi" symbol. Make two pilot holes in each of the four locations where the boards will be connected to the posts. Screw the lag screws into the wood with a socket wrench, using a washer between the head of the screw and the wood on each one. You will need two step ladders and a helper to hold the boards in place. The easiest way to do it is to attach them first with 3-inch deck screws to make sure they are in the right position and then drill the pilot holes.

4 Drill a series of pilot holes on the sides of the posts that face each other. These will be used for the "eye" screws that secure the cables to the posts. Make the holes centered in each post and space them every 12 inches from the ground to the top of the posts.

5 Screw heavy-duty "eye" screws into each of the pilot holes, as far as they will go.

6 Attach the wire to the "eye" screws of one post using cable clamps. You will have to thread the end of each wire through the opening of each cable clamp, pass it through the "eye" hook and then back through the cable clamp the other way, so there is a couple inches that sticks back through the other side. Tighten the nuts of the cable clamps.

7 Unscrew each of the cable tensioners to their maximum dimension, and hook one end onto each of the "eye" hooks of the other post. Starting with the cable closest to the ground, pull each one towards its counterpart on the other post. Again, thread the end of each cable through a cable clamp, pass it through the free end of each tensioner and back through the clamp. Pull it as tight as possible by hand and tighten the nuts of the cable clamp. Cut the excess wire so there is just a couple inches sticking out from each clamp. Finally, tighten the turnbuckles on each of the tensioners with a pair of pliers until the cables are taut.

8 Plant your vine in the middle of the trellis and use a temporary stake to support it as it begins to twine around the cables.

Items you will need

  • Post-hole diggers
  • 4-by-4-inch-by-8-foot posts
  • 2-by-6-inch-by-12-foot boards
  • Concrete mix
  • 2-foot level
  • String level
  • String
  • Reciprocating saw
  • 2 step ladders
  • 3/8-by-4-inch galvanized lag screws
  • 3/8-inch galvanized washers
  • 3-inch deck screws
  • 3/16-inch cable
  • Tape measure
  • Eye screws
  • Drill bit
  • Cable clamps
  • Cable tensioners
  • Socket set
  • Cable cutters
  • Pliers
  • Gloves

Tips

  • As an extra touch, use a circular saw to cut a triangular section out of the ends of each of the 2-by-6 boards. Make a mark 10 inches from the end of the board and another 1 inch below the top of the end of the board. Draw a line between the two marks and make your cut along this line -- you will essentially be removing a triangle of wood that is 10 inches on one side and 4 1/2 inches on the other side. Repeat the procedure on all four boards and mount them so the diagonal cut is facing down.
  • Use pressure-treated wood for the project so it does not quickly rot. Redwood and cedar could also be used, as they are naturally rot-resistant
  • The same approach to making a cable trellis can be scaled up or down if a trellis of a different size is desired.

Warnings

  • Always wear safety goggles and ear protection when working with power tools.
  • Wear a pair of thin gloves when working with the wood to avoid splinters.
  • Call 811 before digging the post holes to make sure there are no underground utilities in the vicinity of the post holes.

Photo Credits

  • Hemera Technologies/AbleStock.com/Getty Images