DIY Cedar Planter Box Plans | Build Your Own In A Weekend

A DIY cedar planter box plan is a cut list plus assembly sequence for building a rot-resistant planter from cedar lumber.

Building your own cedar planter isn’t complicated, but it does require precise cuts and the right assembly order. The payoff is a box that shrugs off rain, snow, and soil contact for years — cedar’s natural oils make it one of the best rot-resistant woods you can buy. Most plans follow the same pattern: side panels, corner supports, and top trim, with drainage gaps left open at the bottom.

What A Cedar Planter Plan Actually Includes

A solid plan gives you two things: a cut list with exact board dimensions, and a step-by-step assembly sequence. The construction pattern stays consistent across most designs. You build two identical side panels, attach corner supports, then connect the long sides and finish with trim.

Here’s what separates a plan that works from one that wastes lumber:

• A complete cut list — every board, sized and labeled before you touch a saw.
• Assembly order — short sides first, then corner supports, then long sides.
• Drainage plan — gap spacing between bottom boards, or a liner with holes.
• Fastener specs — outdoor-rated screws, brad nails, or pocket screws with glue.

Most plans call for cedar fence pickets and 2×2 boards, which are cheap and available at any lumber yard. A few specify pocket screws and glue for extra stability, which means you’ll need a pocket-hole jig.

Standard Sizes And Cut Lists

Planter plans range from small herb boxes to large raised beds. The most common baseline is 24″ x 12″ x 12″ deep, which handles most flowers and shallow-rooted vegetables. Here’s a comparison of typical sizes you’ll find in published plans:

A typical cut list for a 6-foot-long planter looks like this: four 1-by-6 pickets at 72 inches for the long sides, four 1-by-6 at 17.75 inches for the short sides, eight 1-by-2 at 11 inches for corner supports, and trim pieces at 72 and 19 inches. Smaller designs use boards like 1x4x21, 1x4x18, and 1x4x11 in various combinations.

One note on dimensions: exact sizes can vary by up to an inch depending on wood choice and sanding. Cedar fence pickets aren’t milled to tight tolerances, so measure each board before cutting rather than trusting the nominal size.

Where To Find Reliable Plans

Real Cedar publishes a free planter with trellis project plan that’s worth starting with — it’s an official DIY source with professional-grade instructions. This Old House also has a solid cedar planter build with clear photos and a complete materials list.

For sizing guidance, Evergreen’s guide for gardeners explains how to match planter dimensions to what you’re growing. Deep-rooted vegetables need 12 inches or more of soil; shallow annuals do fine in 8-inch depths.

If you’d rather buy than build, we’ve tested the best DIY cedar planter boxes on the market and compared them side by side for build quality and value.

Common Mistakes To Avoid

The biggest failure is skipping drainage gaps. Cedar holds up to moisture, but your plants won’t — waterlogged soil kills roots fast. Leave gaps between bottom boards or drill holes through a solid base.

• Skipping the liner —for damp soil or edible plants, a plastic liner protects the wood and prevents soil from washing out through gaps.
• Misaligned corner supports — if the supports aren’t square, the whole box racks out of shape and won’t sit level.
• Not countersinking screws — exposed screw heads catch on gloves and look unfinished on visible faces.
• Skipping a finish — a penetrating sealer extends cedar’s lifespan significantly, though it will need reapplication every couple of years.

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