If you love the idea of fresh herbs and salad greens just steps from the kitchen but do not want to kneel in the dirt, an elevated planter box is the answer. It sits at waist height, fits on a patio or deck, keeps rabbits and dogs away from your plants, and looks great doing it. We built ours in a single weekend with basic tools and a few cedar boards, and it has quickly become one of our favorite projects. Here is how to build your own.
Why Cedar?
Cedar is naturally resistant to rot and insects, it weathers to a beautiful silver gray if left unfinished, and it is lightweight and easy to cut. Most importantly for edible gardens, it does not need chemical treatment to last outdoors. Avoid older pressure-treated lumber for anything you plan to grow food in.
Finished Size
This plan makes a planter roughly 4 feet long, 2 feet wide, and about 32 inches tall, with a soil bed about 5 inches deep. That depth is perfect for herbs, lettuce, spinach, radishes, strawberries, and shallow-rooted flowers. It is also a size that one person can move with a helper once it is empty.
Materials
- 6 cedar fence pickets or 1×6 cedar boards, 8 feet long (for the box sides and bottom)
- 3 cedar 2x4s, 8 feet long (for the legs and optional shelf rails)
- 2 cedar 2x2s, 8 feet long (for cleats that support the bottom)
- 1-1/4 inch and 2-1/2 inch exterior-rated deck screws
- Exterior wood glue (optional but helpful)
- Landscape fabric
- A staple gun and stainless steel staples
- Potting mix blended with compost
Tools
- Circular saw or miter saw
- Drill and driver
- Tape measure, speed square, and pencil
- Sandpaper or a sanding block
- Safety glasses and hearing protection
Cut List
| Part | Material | Quantity | Length |
|---|---|---|---|
| Legs | 2×4 | 4 | 32 in |
| Long side boards | 1×6 | 2 | 48 in |
| Short side boards | 1×6 | 2 | 22 in |
| Bottom boards | 1×6 | 5 | 22 in |
| Long cleats | 2×2 | 2 | 45 in |
| Short cleats | 2×2 | 2 | 15 in |
| Shelf rails (optional) | 2×4 | 2 | 41 in |
The exact width of cedar boards varies, so measure your actual boards and adjust the short side and bottom lengths so everything fits snugly.
Step 1: Build the Box
Start with the box itself. Lay out the two long side boards and two short side boards so the short boards fit between the long ones. Apply a bead of exterior glue to the ends of the short boards, then drive two 1-1/4 inch screws through the long boards into the ends of the short boards at each corner. Pre-drill your holes to keep the cedar from splitting, especially near the ends.
Check that the box is square by measuring corner to corner both ways. If the two diagonal measurements match, you are square.
Step 2: Attach the Legs
Stand the box on its side and position a leg in each inside corner, with the top of the leg flush with the top edge of the box. Fasten each leg with 2-1/2 inch screws driven through the side boards into the leg from both directions. Placing the legs inside the box hides the joints and gives the planter a clean, finished look from the outside.
Step 3: Add the Cleats
The cleats are the ledge that the bottom boards rest on. Screw the long and short 2×2 cleats along the inside bottom edge of the box, between the legs, so their bottom edge lines up with the bottom edge of the side boards. These carry a lot of weight once the planter is full of wet soil, so use plenty of screws, about every 6 inches.
Step 4: Install the Bottom
Drop the bottom boards in so they rest on the cleats. Leave a gap of about a quarter inch between each board. Those gaps are your drainage, and they are essential. Without good drainage, soil gets waterlogged and roots rot. Screw each bottom board to the cleats at both ends.
Step 5: Add a Shelf (Optional)
A lower shelf adds stability and gives you a handy spot for watering cans, gloves, and small pots. Screw two 2×4 rails between the legs on each long side about 8 inches above the ground, then lay a few leftover pickets across them. It takes about 20 minutes and is well worth it.
Step 6: Sand and Line
Give all the edges a quick sanding to remove splinters, especially along the top rim where your arms will rest. Next, line the inside of the box with landscape fabric, stapling it along the upper sides. The fabric keeps soil from washing out through the drainage gaps while still letting water drain freely. Do not use plastic sheeting, which traps water.
Step 7: Finish or Leave It Natural
You can leave cedar unfinished and let it weather naturally, or apply a food-safe exterior oil or a clear water-based sealer to the outside of the box only. Never coat the inside surfaces that touch soil.
Step 8: Fill and Plant
Fill the planter with a high-quality potting mix blended with about one-third compost. Do not use heavy garden soil, which compacts in containers and adds a lot of weight. Water the mix thoroughly and let it settle before planting, then top it off if needed.
Great plants for an elevated planter include basil, parsley, chives, thyme, oregano, lettuce, arugula, spinach, green onions, radishes, strawberries, nasturtiums, and marigolds. Place taller plants on the north side so they do not shade shorter ones.
Care Tips
Elevated planters dry out faster than in-ground beds because air surrounds the box on all sides. Check the soil daily during hot weather and water when the top inch feels dry. A layer of straw or shredded bark mulch helps hold moisture. Feed plants every few weeks with an organic liquid fertilizer, and refresh the top few inches of soil with compost each season.
Enjoy the Harvest
This is one of the most satisfying DIY projects you can take on in a weekend. You end up with a sturdy, attractive planter that saves your back, keeps pests away, and puts fresh herbs and greens right outside your door. Once you build one, do not be surprised if you find yourself planning a second.
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