Inclined Grape Trellis

Construct a sturdy wooden support to give your grapevines a leg up.

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by Geremy Chubbuck
An angled trellis will keep vines off the ground, allowing for better sun exposure and easier pruning.

Growing grapes is easy, fun, and rewarding. A friend of mine once said that grapes like to suffer, and I’ve found this to be true. Unlike many plants, grapes aren’t finicky, and they require little more than seasonal pruning, full sunlight, and elevation. A sturdy trellis will facilitate two of these three necessities directly (full sunlight and elevation), and aid substantially in the third (pruning). These instructions are for a simple and effective inclined grape trellis sized to accommodate six grape plants; however, you can modify them to accommodate any number of plants. Trellising your grapes will boost production, and it’s easy to assemble this design in one day.

Trellis Considerations

My first trellis was made with maple and birch poles from my property. These were a good way to test the inclined trellis concept without investing money to purchase lumber. Fortunately, the design worked far better than I’d expected, and the grapes flourished. Unfortunately, the poles rotted by the third year, so I decided to upgrade. I’d have preferred to use cedar, but dimensional cedar was unavailable in my area at that time, so I chose pressure-treated lumber instead. You can use whatever type of wood you prefer. Grapevines can grow to be quite heavy, though, so the lumber must be substantial to avoid collapse.

Grapevines need support as they grow. I was fortunate to have a roll of salvaged stainless steel wire on hand when I built my trellis, which I fashioned into a latticework attached to the frame. If you don’t already have a roll of wire, invest in a 304 stainless steel wire that stays in place when bent. Stay away from rope, because it’s not as strong as wire, and it can degrade in the elements.

wooden grape trellis with vines growing on it

This inclined trellis design consists of two primary parts: a vertical part and an angled part. To develop leader lines (the larger vines from which annual vines and grapes spawn), grapes need two vertical cordon lines, one about 20 inches high, and the other 40 inches high. The vertical portion of the trellis will retain the permanent grape vines that run horizontally. The angled incline portion of the trellis will support almost all annual vine and leaf growth, as well as some fruit.

My grape trellis is located in north-central Maine (Zone 4a), slightly above 46 degrees north latitude. My growing season is approximately mid-May through mid-September. In my location, an ideal incline angle for maximum insolation during summer growing months averages approximately 60 degrees from vertical. Because of the materials I had on hand when I built my trellis and the spacing I wanted between posts, my trellis is actually angled at 45 degrees. Fortunately, grapes don’t really care about an exact angle, as long as they receive full sunlight. A solar panel angle calculator, such as the one at Solar Electricity Handbook, can help you find the optimum angle for your trellis.

You’ll want to locate your trellis in a spot that’s generally south-facing (if you live in the Northern Hemisphere) and offers full sun. I’m fortunate to have had a vacant space along the north side of my apple orchard, at the base of the adjacent woods. This south-facing space is the ideal location for a trellis, because it receives full sun and is out of the way enough that the trellis doesn’t shade my other plantings. If you have to choose between facing your trellis precisely south or locating it in full sun, go with full sun, even if the trellis faces slightly east or west.

wooden trellis with a vine growing on it

Tools and Materials

  • Post hole digger or shovel
  • Hand level
  • Cordless drill driver
  • 1/4-inch drill bit
  • Screw bit for construction screws
  • Wire cutters
  • Pliers or vice grips to tension wire
  • Wooden stakes (8)
  • 8-foot-long pressure-treated 4x4s (4)
  • 12-foot-long pressure-treated 4x4s (4)
  • 16-foot-long pressure-treated 5⁄4x6s (3)
  • 12-foot-long pressure-treated 5⁄4x6s (6)
  • 500-foot roll of 304 stainless steel wire
  • 1-1/4-inch construction screws, rated for use with pressure-treated lumber (50)
  • 2-1/2-inch construction screws, rated for use with pressure-treated lumber (50)

Instructions

Begin by marking the trellis post locations using wooden stakes, ensuring that the trellis is facing generally south. Spacing should be about 15 feet center to center along the front and back rows of columns, and about 8 feet between front and back posts. Double-check that the posts are all square to one another, and then dig a 4-foot-deep hole at each stake. Insert the 8-foot-long 4x4s in the front row, and the 12-foot-long 4x4s in the back row. Using a hand level, vertically level the first pole in the front row, and backfill around the pole. Then, use temporary strapping to ensure the spacing remains even, and backfill each of the other 4x4s in the front row, leveling as you go. Repeat this process for the back row. At this point, all the columns should be vertically level and evenly spaced.

close up of wire attached to a wooden board

With the help of a friend, install the 5/6×6 lumber to produce a solid frame, using 2-1/2-inch construction screws. To start, secure the 16-foot boards horizontally across the top of the back row, connecting the back row posts. Then, secure a 12-foot board diagonally from the top of each front row post to the top of each back row post. On both ends, place a 12-foot-long 5⁄4×6 along the incline, wide-side up, to provide strength to both sides. Once all boards are in place, secure all board ends with three construction screws. Add four or more screws along the outer edge of the two horizontal end boards.

To attach the support wires, drill holes through each front row vertical post at 20 inches and 40 inches above grade, and then pull wire through and secure it on each end. For the incline, install 1-1/4-inch screws every 18 inches into each of the 12-foot-long diagonal end boards, leaving about 1/2 inch of screw exposed. Then, string wire between the screws to create a grid. Finally, install wire in an “X” shape in each bay for added rigidity.

Each 15-foot-wide bay is sufficient to accommodate two grape plants. It’s crucial to develop a good vine structure during the first several years of growth. Many good books and articles exist about growing and training grapes. I encourage you to study several sources, as no two seem completely alike. I’ve found the book From Vines to Wines by Jeff Cox to be very helpful. Also, Fedco Seeds is a great resource for selecting, purchasing, and growing grape plants.