Building a Planter Box
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A planter box is a small-scale woodworking project that produces something immediately useful. The construction is simple: four sides joined at the corners with a bottom that drains. You can build one from fence boards, cedar, or even pallet wood. The only critical detail is drainage holes in the bottom so roots do not sit in standing water.
Cost Breakdown
Cutting
Measure and mark all cut lines. Most planter boxes use 4-6 cuts total.
Cuts boards to length. A hand saw works if you only have a few cuts and no power tools.
Marks straight cut lines across boards. Keeps your cuts square.
Assembly
Drives screws at the corners and attaches the bottom. Pilot holes prevent splitting in thin boards.
Hold corners together while you drill and drive. A helper can substitute for clamps.
Pilot holes plus a 1/2-inch bit for drainage holes in the bottom.
Finishing
Smooth rough edges and surfaces before finishing. 120-grit is enough for an outdoor planter.
Apply exterior stain, paint, or sealant. A 2-inch brush covers small planter surfaces quickly.
Consumables and Supplies
These get used up during the project. Always buy these new.
- Cedar or pine boards (1x6 or 1x8) Cedar resists rot. Pine is cheaper but needs sealing for outdoor use. 6-8 board feet for a typical window box.
- Exterior wood screws (1.5-2 inch) Coated or stainless to prevent rust. About 20-30 screws for a small planter.
- Wood glue (exterior) Titebond III for waterproof joints. Apply at corners before screwing.
- Landscape fabric Line the inside to contain soil while allowing drainage through the bottom holes
- Exterior stain or sealant Protects wood from weather. Apply before planting.
Safety Gear
- Safety glasses (sawing and drilling)
- Work gloves (handling rough lumber)
Before You Buy Anything
Check if your neighbors already have the tools you need. Borrowing saves money, saves storage space, and keeps tools in use instead of collecting dust.
See how FriendsWithTools worksCommon Questions
What wood should I use for a planter box?
Cedar is the go-to. It resists rot naturally for 10+ years and weathers to a silver-gray. Pine works if you seal it, but it rots faster in soil contact. Do not use pressure-treated lumber for planters growing food. Modern ACQ treatment is considered safe by the EPA, but many gardeners avoid it. For non-food planters, pressure-treated is fine and cheap.
How many drainage holes does a planter need?
At least one 1/2-inch hole per 12 square inches of bottom area. For a 24x8-inch planter, that is 3-4 holes. More holes are better than fewer. Roots sitting in standing water develop root rot. Elevate the planter on feet or blocks so water can drain freely out the bottom.