Railing planters are a staple of design on homes everywhere, and for good reason. They’re beautiful, practical, and the perfect way to add a pop of life to an otherwise bare spot on your home’s exterior.
However, there are a couple of problems with railing planters (planters you can hang over a balcony, porch, or patio railing) you’ll find at hardware stores; they’re overpriced and under-designed. With this tutorial, you can build your own railing planter that is custom-suited to your needs, your home’s railing, and even the plants you’d like to grow.
What You’ll Need
Equipment / Tools
Planter Box
- Miter saw
- Measuring tape
- Speed square
- Pencil
- Table saw
- Orbital sander
- Brad nailer or hammer
- Drill
- Drill bits
- Screwdriver bits
- Staining brush
French Cleat
- Table saw
- Miter saw
- Measuring tape
- Pencil
- Drill
- Drill bits
- Screwdriver bits
Materials
Planter Box
- 1×8 cedar boards
- Waterproof wood glue
- 2-inch 16-gauge brad nails
- 120-grit sandpaper
- Coco fiber planter insert (optional)
- 8 corner L-brackets
- 5/8-inch exterior wood screws
- Clear wood sealant with UV protection
French Cleat
- Long scrap wood piece
- Self-drilling exterior wood screws
Railing Planter Hooks
- 2 railing planter hooks with mounting hardware
Planning and Building the Railing Planter’s Box
To plan and build the planter box for your railing planter, follow the instructions below. These steps are meant to be adjustable in order to allow you to customize the size and nature of the box to best suit your needs.
- Determine the Dimensions
Before you head to the hardware store, first determine your planter’s dimensions, along with how many planters you want to build. To figure your dimensions for the planter, you first need to decide whether or not you want to use a planter box insert or not. A coco fiber insert will help the planter retain moisture. You also will need to factor in the size and spacing that will best suit your railing.Once you determine your dimensions, use these numbers to gather your materials. We recommend using cedar wood, as it has great resistance to the elements. - Measure and Cut Your LumberUsing a miter saw, cut your boards to length. Because the long sides will be placed overtop of the short sides, their length will be the full length of the planter. Likewise, the length of the short sides will determine the interior depth of the planter. A fifth board should be cut to fit inside the bottom, flush on all sides. If necessary, use a table saw to rip the board to a custom width.
TipIf you don’t own a table saw for ripping, it’s a good idea to alter the short side lengths to account for an unaltered board to fit in the bottom. - Sand the BoardsTo improve the bond of the glue and remove any splinters, thoroughly sand the entirety of each board using an orbital sander and 120-grit sandpaper. Once smooth, remove all dust with a tack cloth.
- Mock up the BoxWhenever you’re working with glue, it’s best to familiarize yourself with the assembly process before applying the glue. This way, you can work quickly and efficiently once the glue is on the wood. Since the priority will be the front of the box, place the long sides over top of the short sides to hide the end grain.
- Assemble the Planter Box Sides
- Assembling the planter is as easy as gluing the joints and nailing the boards together. We recommend a 16-gauge nail gun for its speed and ease, but a simple hammer and brad nails will also do the trick. The nails themselves are merely there to tightly hold the boards together as the glue dries, as the glue itself is stronger than the hold of the nails. Apply glue to each side of the joints, and press the boards together. Once perfectly aligned, drive nails every two inches and at each end. Promptly wipe any excess glue using a rag.
- Secure the Bottom PieceTo add the bottom piece, apply a thin layer of glue along the entire edge of the bottom piece and the corresponding spot on the inside of the box. Slide the bottom into the box, lightly tapping with a rubber mallet if it won’t easily slide into place. Once properly aligned, carefully drive nails around the perimeter, approximately every two inches.
- Drill Drain HolesTo prevent water from collecting inside the planter, drill three to four drain holes in the bottom using a 1/2-inch drill bit.
- Seal the WoodWhile cedar has excellent weather resistance, it will become gray over time. For some people, this is fine, as they appreciate its weathered appearance. However, if you wish for cedar to stay good as new for years to come, apply a clear sealant with UV protection according to the manufacturer’s instructions.
- Add Corner BracesPlants are heavy, so it’s a good idea to add some bracing to your planter box before adding plants. For this, simply install small L-brackets with 5/8-inch wood screws spanning each of the corners. For most planters, two in each corner is adequate, but this number can be adjusted depending on the size of your planter. Furthermore, it’s your choice whether you’d like to place the brackets on the inside to maintain the planter’s sleek look, or on the outside to add a more industrial accent.
