How to Build a Trellis That’ll Upgrade Your Yard in 6 Easy Steps

Cut Your Wood to Proper Dimensions

“A trellis or pergola is a great addition to any outdoor space,” says Bob Tschudi, Angi Expert Review Board member and general contractor in Raleigh, NC. “These wood structures add texture and depth to your property.”

This step-by-step guide for building a garden trellis is perfect for 4-foot raised garden beds filled with flowering vines and fruits and vegetables. Adjust your measurements accordingly if you have larger or smaller beds or simply would like to build a trellis using different dimensions.

Purchase real plywood, not OSB or MDF, which will deteriorate quickly outdoors. Cut your plywood into 4-foot-by-8-inch and 3-foot-by-8-inch pieces. These will form the frame of your trellis.

Pre-Drill Your Frame Pieces, Then Assemble

A trellis is a grid for plants to attach/be guided as they grow. In this example, we are looking at four 4-foot-by-4-foot trellises. The grid itself is made of string. Most big box home improvement stores sell plywood in 4-foot-by-4-foot sizes. 

“When we use plywood for outdoor applications, we always coat the cut edges with latex caulk,” says Tschudi. “That keeps moisture and water from penetrating the vulnerable layers of wood. We also stain or paint the wood, which adds additional protection.”

Using a circular saw or a table saw, cut the 4-foot-by-4-foot plywood into 3-inch-by-4-foot strips. (Cut it to just under 3 inches per strip, as the saw blade itself makes the pieces smaller. On a table saw, set it to 2 7/8 inches.) From a 4-foot-by-4-foot piece of plywood, you should get 16 strips, which will give you four 4-foot-by-4-foot frames.

Use your power drill to drill starter holes into the corners of your frame. You’re working with plywood, which can be sort of fragile, so this will help prevent it from breaking during assembly.

Use a screw to secure your frame at all four corners. The final structure should be rectangular. If you’d like, you can cut corner support pieces with a fifth piece of plywood and add those for reinforcement.

Place Nails Halfway Into Your Frame on the Inside

Next, use small nails every 6 inches along the frame on each side. Only nail them in halfway, as you’re going to need the exposed nail in a later step to create the trellis.

This simple approach works differently than building an obelisk trellis, which uses pieces of wood at the base and corners.

Line Your Trellis With Cotton Thread

Weave your chosen thread around the nails on the outside of the frame. Start weaving horizontally, then once you reach the bottom, switch to a vertical weave. You should then have about 70 squares in your trellis, but if yours is a little higher or lower, that’s fine.

If you’re using a string, aim to use one that doesn’t use polyester. This makes it recyclable. At the end of each season, you can simply cut the string and rethread it with next year’s crops.

Some homeowners prefer to use wood to line their trellis, especially if their trellis will be used as a privacy measure along fences so vines can grow. If that’s the case, you can use the same type of plywood for the frame. You can paint or stain it, too, if desired.

Another popular option is remesh, which is a thin, non-galvanized type of steel.

Attach Spikes to the Base, Then Dig a Hole

Photo: krblokhin / iStock / Getty Images

To secure your trellis, take a trowel and dig two 6-inch holes in the garden bed, along the fence, or wherever it will lie. Make two 6-inch spikes out of leftover plywood by cutting the ends at an angle to form a point. Screw these onto the base.

“Whenever you have wood touching soil or exposed to water, it’s best to protect the wood,” says Tschudi. “At the very minimum, coat any wood that will be in contact with soil or water with caulk. Just smooth it over the surface. This will delay the inevitable contact and decay of the wood.”

Push the spikes into your holes in the garden and rearrange any existing plants or vines accordingly. (A local gardening pro can give you ideas if you’re still trying to decide what to grow.)

(Optional) Build a Second Trellis, Then Attach

If your DIY trellis is going in a garden or raised garden bed, you may want to make a second trellis to help with a row of plants behind it. This method is also useful because it allows the two trellises to freestand. Plus, it just looks cool.

Make a second trellis, then cut two pieces of plywood to the desired length. Fasten them together at the top with screws, then place all four corners of the trellis in your garden.