Building a Cedar Grape Trellis

In this Instructable, I'll show you how I made a cedar grapevine trellis for the side of our front porch, as a way to take advantage of otherwise underutilized space in our small yard.

If you'd rather watch a build video before jumping into the Instructable, be sure to watch the full video above. If you like it, please consider subscribing to my YouTube channel so I know this is the type of project people enjoy learning how to make themselves so that I can make more videos like it in the future! I've included links below to the tools and materials I used, but feel free to adapt what you learn here to build a trellis specifically suited to your own space!

Below I've listed the supplies you'll need to build the exact trellis I built. I tried to make the instructions easier by listing lumber in the size you'll likely find it at the store, then in parenthesis indicating what size to cut it to for final assembly or further working).

• 2x – 4" x 4" x 10' cedar fence posts
• 4x – 3.5" x 0.75" x 8' cedar boards (cut to 7' in length)
• 1x – 3.5" x 0.75" x 8' cedar boards (cut into two 43.75" lengths)
• 2x – 5.5" x 1" x 8' cedar boards (cut to 51.75" in length)
• 1x – 5.5" x 1" x 8' cedar boards (cut to 53.75" in length)
• 8x – 1" x 48" wooden dowels (cut to 40.25")
• 4x – 6" x 0.5" carriage bolts
• 4x – 1.5" x 0.5" washers
• 4x – 0.5" nuts
• 2x – Bags of expanding foam post hole filler
• 1x – Box of deck screws

In the previous step, I described the supplies you'll need to build these trellises, now let's talk about the tools you'll need to assemble them. Don't be intimidated by the following list – you don't need a sander, for example, if you're not afraid of using a little elbow grease to hand sand.

Many of the other tools can easily be borrowed from a local "tool library" or be used at a maker space. I've slowly acquired some of my own tools over the years, but I still don't own everything I needed, so I used tools available to me at my local maker space in certain steps. I encourage you to look up maker spaces near you if you're concerned about not having your own tools as most moderate size cities will have one or more maker spaces for you to use.

Tools Used:

• Drill Press (to drill straight holes for dowels)
• 1 1/16" Forestner Bit (to make clean, flat bottomed holes for dowels)
• Cordless Drill (for decking screws)
• Random Orbital Sander (for finish sanding once complete)
• Post Hole Digger (for easy digging of holes)
• Fence Post Level (for leveling front-to-back once in ground)
• 24-inch Level (for leveling side-to-side once in ground)
• Reciprocating Saw (for cutting excess expanding foam)
• Shop Vac (for cleanup of expanding foam dust)

The first thing I did before even buying my materials was to gather inspiration of various trellises online that I liked. This rose trellis came up in my search and looked a lot like what I had in my head, but there were a few aspects I didn’t like – for instance, it appears as though the horizontal cross members are made of copper pipe, which I felt like grapes might have a hard time gripping onto, if not get burned in the sun. Also I didn’t love how the vertical cross members terminated shy of the top and bottom – I felt like they should continue through to hide their end grain. Overall I liked it though, and decided to use it as a basis for my own design.

If you just want to build the same trellis I did, read on and feel free to skip the design portions.

With a rough idea of what I wanted my trellis to look like, I took to the computer to try to make myself some plans in Autodesk Fusion 360. I really want to learn this program, as I want to get into CNC work in the future where it’ll be invaluable to me, but after an hour of futzing around in there without much luck, I decided to switch to a program I know better, which is Adobe Illustrator.

Adobe Illustrator isn’t a CAD or physical world design program, but I mostly just needed to be able to work in 2 dimensions. This trellis was only going to be about 6-8 inches in depth and I could do what few 3rd dimension calculations there were to do in my head. So ignoring the 3rd dimension temporarily, I used Illustrator to plan out the front profile.

One thing worth noting here is that towards the end of the design process, I updated my design to use 10 foot cedar posts instead of 8 foot cedar posts – something I didn't know was an option until I saw them at the home improvement store. This raised my trellis to 8 feet tall once 2 feet were buried in the ground, which felt a lot more natural from the perspective of someone up on our porch which this would be next to, where they otherwise would have felt too short.

Again, you can skip this step if you want to use my design.

For the intersections between horizontal and vertical supports on the internal framing, I would have loved to have used the same size boards for each direction and done lap joints with squared lumber. But I’m a pretty novice woodworker in that I’ve never done anything this large and structural, nor have I done much traditional woodworking or complex joinery. So trying to get that many lap joints perfectly aligned for the first time on 10 foot cedar posts that aren't exactly cheap didn’t exactly sound like a very good way to practice.

So what I decided to do instead was use dowels for the horizontal crossmembers. All that this required was drilling perpendicular holes through all of my vertical pieces where dowels could simply be slid through to create the internal framing. The downside to this was that 1” dowels at the store were kinda spendy for what they were, and I needed 8 of them, but it was a tradeoff I was willing to pay to simplify my project. I'll practice lap joints on a smaller scale so that I'll feel more confident with the advanced technique in the future.

So with that approach, I got started by drilling my holes in the 7 foot boards with the 1 1/16 forestner bit. I had access to a large drill press at my local maker space, so I used that, but I just as well could have used my small drill press at home. The benefit to the larger drill press was being able to clamp my boards together and drill through all of them at the same time, minimizing the likelihood of errors from board to board. If all I had access to was the smaller drill press, though, I would have used that and been very careful.

I highly recommend using a drill press for all the holes in this project, as it will guarantee your holes are straight and not crooked. Even if you're careful while using a hand drill, your holes will end up a little crooked and the dowels won't fit as well. We use a drill bit that is 1/16" larger than our dowels to help the dowels fit easier.

I drilled the same holes in my 4"x4" cedar posts, but for those I used my drill press at home, as I could set it down in my driveway and more easily support the overhanging ends than I could using the standing unit at the maker space. For the 4"x4" posts, we only drill our holes half way through, so use the depth gauge on the drill press to drill down about 1.75" inches. The forestner bit will give you a nice, flat bottomed hole.

On both the 7 foot boards and the 4x4 posts, you'll be drilling 8 holes – starting at 9.5" from the top and continuing every 9 inches until you reach 72.5".

Next up, I cut the quarter circle out of the bottom two corners of the 51.75" boards. I ended up using the bandsaw at the maker space since I was already there to use the large drill press, but I just as easily could have done this with the jigsaw at home. Ironically, I forgot to cut the bottom arch between the two quarter circles, so I had to use my jigsaw to do this.

With all of our holes drilled and our decorative cap pieces cut to size, we can begin assembly! I started by placing the dowels part way through one of our vertical uprights to align all of the dowels, then inserted each dowel into the corresponding hole on one of the 4"x4" cedar posts. After they are inserted, stand the assembly up on end and tap your dowels all the way down. You'll hear the "thud" change pitch as you reach the bottom of the holes. Once the dowels are fully inserted into the 4x4" posts, use a few screws to hold them in place from the side.

Using a 5" spacer board, tap the first 7 foot vertical upright further down the dowels until the gap between it and the 4x4 is a consistent 5" between every post. I used a spare 2x4 to help tap the upright into place. Once in place, I again used a few screws to hold it in place so that further vibration wouldn't knock it out of alignment.

Continue adding the remaining 7 foot uprights onto the dowels from the top, and tap them into place using a hammer or your 2x4 makeshift hammer. While the lower-most upright was spaced 5" from the post, the inner uprights are spaced 8" from each other, so use another spacer block to achieve this consistently across the length of the trellis. Again use screws to tie in each upright until they are all secured.

After all of the 7 foot boards have been added, we can hoist the other 4x4 post on top of the assembly, hole side down to fully receive the dowels. Tap it all the way down and secure it with some screws.

Before we can add the decorative cap, we need to drill a few holes. In each "face" (the board with the arches), we'll drill a 1/2" hole 2.75" from the top and 5.75" from the side. On one of the boards (whichever one looks nicer, as it'll be the outward facing one) you'll need to chisel out the corners with chisels if you have them or even a flathead screwdriver. This doesn't need to look pretty, but it's necessary since the back side of carriage bolts have a square neck.

You'll also need to drill a hole at the top of each of your 4" x 4" cedar posts, the same 2.75" down. I recommend doing this before the framing assembly, but it can absolutely be done later. Make this an oversized hole using your 1 1/16" drill bit, as it'll make assembly easier and give you some wiggle room when leveling the trellis later.

Secure the faces to the posts with a washer and nut on the backside.

Add the 53.75" board to the top of these boards with some deck screws, centered to form the top of the decorative cap.

We're in the home stretch! Now that the decorative cap is on, we can secure the bottom board that covers where the 7 foot boards end. Use the two 43.75" boards for this, one on each side of the trellis. I'm using decking screws to attach to the 4x4 posts in these photos, but later I changed this to be carriage bolts to better match the top.

After that's secured, we can finish sand to knock of any rough edges or remaining marker lines from our measuring.

With our trellis fully assembled, it's time to get it mounted and in use! Carefully move the trellis into place, where you've prepared two carefully measured and dug holes. You'll definitely want someone to help you stand it up on end, because while it's not overly heavy, it's heavy enough that it's hard to control once standing.

You'll want your holes to be 24" down, give or take.

After it's in the holes. using your post leveler and 24 inch level, carefully make sure it's plumb and level in all directions. I used a spare 4x4 post to hold our trellis in place while we made sure it was level.

To mount the trellis, we'll use expanding foam post hole filler. This is an alternative to cement that is super easy to work with. You simply roll the bag, mix, and pour. Moments later it's filled every nook and cranny of the hole and within a few hours it's fully cured and you can cut away the excess.

I used a reciprocating saw to cut away the excess here; this created some foam dust, so I used my shop vac to clean this up out of the dirt.

After the foam was cut and cleaned up, I covered up the base of the posts with mulch.

That's it! I’m absolutely thrilled with how my trellis turned out, and I hope you feel empowered to build one yourself! It may seem like a complicated build in terms of steps, but when broken down, it's really pretty basic!

We're using our trellis to grow grapes on the side of our front porch, but this would work well in any part of your yard to take advantage of otherwise wasted space.

Be sure to watch the video above for more details, and if you like it please consider subscribing to my YouTube channel for more projects like this.

If you liked this project and thought I did a good job explaining the process, please consider voting for me below in the "Backyard Contest" here on Instructables! I appreciate your vote!