How to Build a DIY Deck Railing Planter Box

Required Tools for a DIY Railing Planter

• Worktable
• Hammer
• Clamps
• Carpenter’s square
• Power drill with a flat bit
• Table saw
• Tape measure
• Circular saw

How to Build Deck Rail Planters

You can modify the design of your planters to better fit its intended space. For instance, if your deck was designed with a shorter rail, you could easily make these 48” planters a little shorter to fit. You just have to follow a few simple steps.

Step 2 – Transform the Box into a Planter

Using a flat ½” drill bit, create several drainage holes along the base of the planter. This will help to ensure your plants are not overwatered and that water does not pool at the base of your planter.

Step 3 – Finishing Touches

Sand down rough spots and adhesive residue that may have seeped out, then use a moist cloth to wipe away residue. While the planter is drying off, use your bottom board measurement to cut a nylon or vinyl liner for the base of the box. Allow the planter to finish drying before applying stain or paint. If you use composite to build your planters, paint or stain will not be necessary. However, if you do paint or stain your planters, allow them to dry again before adding soil.

How to Secure Railing Planters?

How do you attach planters to handrails? You have several options, but the simplest and most secure choice, if you have a wooden railing, is screwing them into your railing. Using a single woodscrew on each end of the planter is typically sufficient for holding them in place.

However, some people are understandably hesitant to drill into their deck’s railing. Another option for securing your deck railing planter is to purchase an attachment bracket for a hardware store. Brackets may be easier on your railing and can allow you to lift and move your planters as needed.

Building your own railing planters are an easy and inexpensive DIY project that can add more life, greenery, and color to your deck -- all while saving precious space.