DIY Cedar Planter Boxes: A Step-by-Step Guide

Updated at: 24/03/2025

Cedar wood, with its natural beauty and inherent resistance to rot and decay, makes an ideal material for crafting long-lasting planter boxes. These elegant additions to any garden or patio not only provide a stylish home for your favorite plants but also add a touch of rustic charm to your outdoor space. Building your own cedar planter boxes is a rewarding project, allowing you to customize the size, shape, and finish to perfectly complement your existing landscaping and personal style. You’ll be surprised how simple it is to transform rough-cut cedar into a functional and beautiful focal point.

Forget expensive, mass-produced planters; this comprehensive guide will walk you through each stage of constructing your own beautiful cedar planter boxes. From choosing the right lumber to the final finishing touches, we’ll provide a detailed, step-by-step process that will empower you to create stunning planters with minimal tools and effort. Let's get started!

Preparation and Safety Guidelines

Tools Needed
  • Cedar fence pickets (or treated pine)
  • Table saw
  • Miter saw
  • Sandpaper
  • Kreg 720 Pro pocket hole jig (or similar)
  • 1-inch pocket hole screws
  • Exterior wood glue
  • Brad nails
  • Clamps
  • Strap clamps
  • Measuring tape
  • Drill
  • Safety glasses
Safety Guidelines
  • Always wear safety glasses and a dust mask when cutting and sanding cedar wood. Cedar dust can be irritating to the eyes and lungs.
  • Use caution when operating power tools. Ensure proper ventilation and follow all manufacturer's instructions.
  • Treat the cedar wood with a weather-resistant sealant before planting to protect it from rot and extend its lifespan. Allow the sealant to dry completely before adding soil and plants.

Step-by-Step Instructions

  1. Prepare the Cedar Pickets

    • Sand down the cedar fence pickets to smooth the rough texture.
    • Rip the fence pickets down to 1 3/4 inch strips using a table saw.
    • Cut the strips to the desired lengths using a miter saw (dimensions are provided in the linked plans).
    Cut the strips to the desired lengths using a miter saw (dimensions are provided in the linked plans).Cut the strips to the desired lengths using a miter saw (dimensions are provided in the linked plans).Cut the strips to the desired lengths using a miter saw (dimensions are provided in the linked plans).
    Prepare the Cedar Pickets

  2. Prepare the Stretchers

    • Drill pocket holes into the stretchers using a pocket hole jig.
    Drill pocket holes into the stretchers using a pocket hole jig.
    Prepare the Stretchers

  3. Assemble the Planter Sides

    • Attach two legs and two stretchers for each side using pocket hole screws and wood glue. Measure 1 1/2 inches from the bottom for the bottom stretcher.
    • Attach backer pieces to the two larger sides using wood glue, brad nails, and screws, leaving space for the smaller sides.
    Attach backer pieces to the two larger sides using wood glue, brad nails, and screws, leaving space for the smaller sides.Attach backer pieces to the two larger sides using wood glue, brad nails, and screws, leaving space for the smaller sides.
    Assemble the Planter Sides

  4. Complete the Planter Box

    • Attach the two smaller sides to the larger sides using wood glue and pocket hole screws.
    • Add bottom slats for support and plant placement, evenly spaced and fastened with wood glue and screws.
    Add bottom slats for support and plant placement, evenly spaced and fastened with wood glue and screws.Add bottom slats for support and plant placement, evenly spaced and fastened with wood glue and screws.
    Complete the Planter Box

  5. Assemble and Attach the Top Cap

    • Cut 45-degree miters on the cap pieces. Assemble the top cap using pocket hole screws, glue, and staples.
    • Attach the top cap to the planter using wood glue and brad nails, ensuring even overhang.
    Attach the top cap to the planter using wood glue and brad nails, ensuring even overhang.Attach the top cap to the planter using wood glue and brad nails, ensuring even overhang.
    Assemble and Attach the Top Cap

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Tips

  • Use a stop block on your miter saw for consistent cuts.
  • Be careful not to over-tighten screws when attaching the backer pieces.
  • Use clamps to keep everything square during assembly.
  • Tack pieces in place with brad nails before using screws for easier assembly.

Common Mistakes to Avoid

1. Untreated Cedar

Reason: Using untreated cedar can lead to rot and decay, especially when exposed to moisture.
Solution: Always use cedar that is pressure-treated or naturally weather-resistant to ensure longevity.

2. Inadequate Drainage

Reason: Poor drainage can cause waterlogging, leading to root rot and plant death.
Solution: Drill drainage holes in the bottom of the planter box to allow excess water to escape.

FAQs

What type of cedar is best for outdoor planter boxes?
Western Red Cedar is a popular choice due to its natural resistance to rot and insects, making it ideal for outdoor use. Incense Cedar is also a good option.
Do I need any special tools to build a cedar planter box?
Basic woodworking tools are sufficient: a saw (circular saw or hand saw), a drill, screws, a measuring tape, and a level. Clamps are also helpful for assembly.
How do I protect my cedar planter box from the elements?
While cedar is naturally resistant, applying a high-quality exterior-grade sealant or stain will extend its lifespan and enhance its beauty. This helps protect against moisture and UV damage.