Making a Wooden Outdoor Planter With Trellis: Genius Essential Project

Making a wooden outdoor planter with a trellis is a fantastic DIY project! It adds vertical appeal and growing space to your garden and is surprisingly achievable for beginners. This guide will show you exactly how to build one, step-by-step, making it easier than you think.

Hey there, DIYers and garden lovers! Jack Shaffer here, ready to tackle another fantastic woodworking project with you. Ever look at your patio or balcony and wish you had a little more green space? Maybe you’ve got some climbing plants like ivy or clematis that are just begging for a place to grow upwards. Well, I’ve got the perfect solution that’s both beautiful and practical: a wooden outdoor planter with a built-in trellis. It’s a project that really upgrades your outdoor living area, giving you room for flowers, herbs, or veggies, while those charming vines can scramble up and create a lovely natural screen or focal point. We’ll break it down, step by step, so you can build this yourself, even if you’re new to woodworking.

We’ll cover everything from choosing your wood to the final coat of finish. You’ll be amazed at how rewarding it is to create something so functional and attractive with your own two hands. Stick with me, and by the end of this guide, you’ll have a gorgeous, custom-built planter that will impress your neighbors and delight your green thumb.

Table of Contents

Why This Project is a “Genius Essential”

This planter-with-trellis project isn’t just another weekend DIY; it’s a genuine game-changer for small or even large outdoor spaces. Think about the benefits:

Space Saving: It utilizes vertical space, which is gold for small yards, balconies, or patios.
Aesthetic Appeal: It adds architectural interest and a touch of rustic charm to any outdoor setting.
Promotes Plant Growth: Trellises provide support for climbing plants, encouraging healthier and more abundant growth.
Customizable: You can adjust the size and design to perfectly fit your space and style.
Beginner-Friendly: With the right guidance, this project is totally achievable for those just starting out in woodworking.

It’s a project that delivers big on style and function without demanding advanced skills. You’re essentially building two useful garden features in one harmonious unit!

Tools and Materials You’ll Need

Before we get our hands dirty, let’s gather everything. Having all your tools and materials ready makes the building process smooth and enjoyable. Don’t worry if you don’t have everything; many of these are common woodworking items, and you can rent or borrow specialized tools if needed.

Essential Tools:

Measuring Tape: For accurate cuts and assembly.
Pencil: To mark your wood.
Safety Glasses: Always protect those eyes!
Work Gloves: Keep your hands protected.
Circular Saw or Miter Saw: For making straight, clean cuts on your lumber. A miter saw offers more precision for angled cuts, but a circular saw works perfectly well.
Drill/Driver: For pre-drilling holes and driving screws.
Drill Bits: Various sizes for pilot holes and clearance holes.
Countersink Bit: To sink screw heads flush with the wood surface.
Clamps: To hold pieces together securely while you assemble them.
Square (Combination or Speed Square): To ensure your cuts and assembly are at perfect 90-degree angles.
Sandpaper (various grits: 80, 120, 220) or Orbital Sander: For smoothing surfaces and edges.
Paintbrush or Roller: For applying your chosen finish.

Materials List:

For a planter of approximate dimensions (e.g., 36 inches long x 18 inches wide x 20 inches high for the planter box, with an 18-inch trellis extension), you’ll need:

Lumber: Cedar or Redwood are highly recommended for outdoor projects. They are naturally resistant to rot and insects. Pressure-treated lumber is another option but ensure it’s rated for ground contact if you plan to place it directly on soil.

(4) 2x4s, 8 feet long (for the planter frame and supports)
(4) 1x6s, 8 feet long (for the planter sides)
(1) 1×4, 8 feet long (for trellis slats and top cap)
(1) sheet of 1/2-inch exterior-grade plywood or lattice (for the planter bottom)

Wood Screws: Exterior-grade, rust-resistant screws (e.g., deck screws).

1 1/4-inch screws (for attaching siding)
2 1/2-inch screws (for structural framing)

Wood Glue: Exterior-grade wood glue for extra strong joints.
Optional: Landscape Fabric or Plastic Liner: To protect the wood from direct soil contact and moisture inside the planter.
Optional: Wood Sealer or Stain: To further protect the wood and enhance its appearance.

A Note on Lumbers: Using naturally rot-resistant woods like cedar or redwood will significantly extend the life of your planter. If you opt for pine or fir, a good quality exterior stain or sealer is a must. For helpful information on choosing exterior wood, check out the Wood Database’s guide to outdoor woods.

Planning Your Design and Dimensions

Before you cut a single piece of wood, it’s smart to sketch out your planter. The dimensions I’ve suggested are a good starting point, but feel free to adjust them. Think about where it will go:

Size: Will it fit the space? Do you want it to hold many plants or just a few?
Depth: How deep does it need to be for the plants you want to grow? Most vegetables and flowers do well in planters 10-12 inches deep.
Trellis Height: How tall do you want your climbing plants to grow?

For this guide, we’ll work with a planter box that’s roughly 36 inches long, 18 inches wide, and 20 inches high. The trellis will extend about 18 inches above the planter box, making the total height around 38 inches.

Cutting List:

Based on these dimensions, here’s a cutting list to get you started. Remember to measure twice, cut once!

Component	Lumber Type	Dimensions	Quantity
Planter Box – Long Sides	1×6	36 inches	4 pieces
Planter Box – Short Sides	1×6	15 inches	4 pieces
Planter Box – Bottom Slats (optional, for support)	1×4	15 inches	2 pieces
Planter Box – Corner Supports (vertical posts)	2×4	20 inches	4 pieces
Planter Box – Assembled Frame (horizontal supports)	2×4	33 inches (for length sides)	2 pieces
Planter Box – Assembled Frame (horizontal supports)	2×4	15 inches (for width sides)	2 pieces
Trellis – Vertical Supports	2×4	38 inches (total height: 20″ box + 18″ trellis)	2 pieces (these will likely be extensions of the front and back corner posts)
Trellis – Horizontal Slats	1×4	15 inches	Approx. 8-10 pieces (spacing as desired)
Planter Box – Bottom Plywood/Lattice	1/2″ Plywood/Lattice	33 inches x 15 inches (to fit inside the frame)	1 piece

Important Note on Vertical Supports: For added strength and to create your trellis anchor points, we’ll be using 2x4s for the internal corner posts that extend up to support the trellis. So, those 20-inch corner supports will actually be cut longer as part of the trellis integration.

Step-by-Step: Building Your Planter with Trellis

Let’s get building! We’ll start with the planter box and then integrate the trellis. Wear your safety glasses and gloves.

Step 1: Construct the Planter Box Frame

This is the sturdy backbone of your planter. We’ll build a simple rectangular frame using 2x4s.

Take two 2x4s cut to 33 inches (for the long sides) and two cut to 15 inches (for the short sides).
Lay them out to form a rectangle. The 15-inch pieces will fit inside the ends of the 33-inch pieces.
Apply exterior wood glue to the ends of the short 15-inch pieces.
Align the pieces to form a 36-inch by 18-inch outer dimension rectangle. Use a square to ensure corners are at 90 degrees.
Clamp the corners together securely.
Pre-drill pilot holes through the longer 33-inch pieces into the ends of the 15-inch pieces. Use a countersink bit so the screw heads will sit flush.
Drive two 2 1/2-inch exterior wood screws into each corner.

You now have the main frame for your planter.

Step 2: Add the Vertical Corner Supports

These 2×4 posts will go inside each corner of your frame. They add significant strength and will be the anchor for your trellis.

Cut four pieces of 2×4 to 20 inches long.
Position one 2×4 post inside each corner of your assembled frame. Ensure they are flush with the top and bottom edges of the frame.
Apply wood glue to the sides of the 2×4 post that will touch the frame.
Clamp each post in place.
Pre-drill through the outside of the planter frame into the 2×4 post. Use two 2 1/2-inch screws per side for each post.

It’s crucial these posts are sturdy, as they’ll support the weight of your plants and the trellis structure.

Step 3: Attach the Planter Box Sides (1x6s)

Now we’ll clad the frame with your 1×6 boards to create the planter box walls.

Take your 1×6 boards. You’ll need four cut to 36 inches (for the long sides) and four cut to 15 inches (for the short sides).
Start with a long side. Apply a bead of wood glue along the outside edge of the 33-inch 2×4 frame piece and also along the edge of the 2×4 corner posts.
Align one 36-inch 1×6 board flush with the top edge and the outer edge of the frame.
Clamp it in place.
Pre-drill pilot holes through the 1×6 board into the 2×4 frame and corner posts.
Use 1 1/4-inch exterior wood screws, spacing them about 6-8 inches apart. You can use a countersink bit to make them neat.
Repeat this process for the other long side.
Now, attach the shorter 1×6 boards (15 inches long) to the ends. Apply glue to the exposed 2×4 frame and corner posts. Ensure the bottom edge is flush with the bottom of the frame.
Add screws as you did for the long sides.
Continue adding the 1×6 boards, stacking them up to create the desired 20-inch height. Overlap the corners so the side boards overlap the end boards for a cleaner look and better water shedding.

For a 20-inch height using 1×6 boards (which are actually about 5.5 inches wide), you’ll need about four boards high on the sides. You might need to rip one board (cut it lengthwise) to get the exact height if you want it precise, or just let it be slightly shorter.

Step 4: Install the Planter Bottom

This creates the base for your soil.

Cut a piece of 1/2-inch exterior-grade plywood or lattice to fit inside the planter frame. It should be approximately 33 inches x 15 inches.
Position this plywood piece inside the planter box, resting it on the lower 2×4 frame members.
To allow for drainage, you can either drill several 1/2-inch holes in the plywood before installing it, or skip this step if using lattice.
Secure the plywood bottom by pre-drilling and screwing through the 1×6 siding into the edges of the plywood. Use 1 1/4-inch screws.

Alternatively, you can screw a few 1×4 slats across the bottom of the 2×4 frame to create a slatted bottom, which offers excellent drainage. Cut two 1x4s to 15 inches and screw them into the lower 2×4 frame.

Step 5: Prepare and Attach the Trellis Supports

Now we extend the corner posts upwards to form the trellis structure.

From your remaining 2×4 stock, cut two pieces to 38 inches long. These will be your primary vertical trellis supports.
Identify the two front corner posts of your planter. These are the ones that will face outwards from your main line of sight.
Apply wood glue to the top ends of these two corner posts.
Position one 38-inch 2×4 vertically on top of each front corner post. Ensure they are flush with the outside of the planter box and perfectly vertical.
Clamp them firmly in place.
Pre-drill pilot holes through the side and front of the planter box’s 2×4 frame and into these vertical supports.
Drive 2 1/2-inch screws to secure them. You’ll want at least two screws from the side into the support and two from the front into the support.

These extended posts now form the sturdy vertical elements of your trellis.

Step 6: Add the Trellis Slats

These are the horizontal pieces that climbing plants will use to grab onto.

Take your 1×4 boards. Cut them to 15 inches long for the horizontal trellis slats. You’ll need about 8-10 pieces, depending on how much coverage you want.
Decide on the spacing for your trellis slats. A common spacing is 6 to 8 inches apart.
Starting from the top of your extended 2×4 supports (or slightly below, depending on your desired look), position your first 1×4 slat.
Ensure the slat is level and centered on the 2×4 supports.
Clamp it in place.
Pre-drill pilot holes through the 1×4 slat into the 2×4 trellis supports.
Drive 1 1/4-inch exterior wood screws in each end.
Continue adding slats, maintaining consistent spacing, working your way down towards the planter box.

You can also add a horizontal slat across the top of the 1×6 planter sides, connecting the base of the trellis supports, for a more finished look. Cut a 1×4 to 36 inches and attach it to the front and back.

Step 7: Sand and Finish

A little sanding makes a big difference!

Use sandpaper (start with 80-grit for any rough spots, then move to 120-grit, and finally 220-grit for a smooth finish) or an orbital sander to smooth all the surfaces, edges, and corners of your planter and trellis.
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