An elevated garden bed is a freestanding planter on legs with a slatted floor, built from lumber and deck screws for better drainage and easier access.
An elevated bed brings soil up to a comfortable working height, sits above ground with a floor that lets water escape, and delivers fewer weeds, fewer burrowing pests, and no kneeling. The build takes a weekend with standard lumber and basic tools, using one repeating sequence: legs, side panels, a bottom lip, and a slatted floor. Before cutting, mark the spot and choose a sunny, level location with good drainage. Clear grass and weeds, lay cardboard under the bed to suppress growth, and call 811 first if you’ll dig — it’s free and keeps you clear of gas and electric lines.
Cut List and Materials
One published DIY plan uses these exact cuts from standard lumber:
Cut floor slats to fit the interior width, leaving small gaps for water flow. A 1 x 2 inch strip screwed along the inside bottom edge forms the lip holding the floor pieces. Any pressure-treated or naturally rot-resistant lumber works, and University of Minnesota Extension guidance notes that material choice matters for food beds — pick lumber safe for edible gardening and avoid anything that could leach harmful chemicals into the soil.
Assembly: Legs First, Then Panels, Then Floor
Build four leg units first: fasten two legs to a support board, repeat for the other pair, then attach bottom short-leg pieces just below the support board. Stand the legs in “H” shapes, then connect them with the long side pieces, adding panels one at a time until the box is enclosed. Pre-drill pilot holes at every joint — deck screws driven without them split the lumber, the most common rookie mistake. Use deck screws for all corner fastenings; if stacking a second layer, the RHS recommends vertical batons inside the corners for strength. Once the box is up, screw the 1 x 2 inch strip along the inside bottom edge, cut bottom pieces to fit, and lay them in with small gaps for drainage. For deeper beds, lay hardware cloth before the slats — it lets water through while blocking burrowing pests.
Fill, Plant, and Avoid Common Mistakes
Fill the bed to about 2 inches below the rim and let soil settle for two weeks before planting, per RHS guidance. Keep the bed at 4 feet wide or less so the center is reachable from either side — skipping that forces stepping into the bed, compacting soil and undoing the purpose. Other failures to dodge: skipping pilot holes, placing the bed on uneven ground without leveling, and neglecting bottom drainage. On slopes, cut a shallow trench for the first board so the structure sits square and stable.
Key dimensions and facts at a glance:
| Element | Recommendation |
|---|---|
| Bed width | 4 feet or less for reachable center |
| Fill level | 2 inches below the rim |
| Soil mix | 3 parts organic matter, 2 parts sand, 7 parts topsoil |
| Bottom drainage | Slatted floor with small gaps plus hardware cloth for pests |
| Fasteners | Deck screws with pre-drilled pilot holes |
Finishing Touches and What to Avoid
Leveling the first board on uneven ground is non-negotiable — the structure settles into whatever slope it sits on, making water pool at the low end. If the spot has poor drainage, raise the bed higher or build it over gravel. Let soil settle for two weeks before planting; planting into fresh loose soil means the bed drops and roots end up shallower than intended. Water well during that period. The trade-off of a DIY build: exact dimensions at lumber cost, but a weekend of measuring and cutting. If you’d rather skip the saw work, a small elevated garden bed roundup covers tested options that arrive assembled or near-assembled.
References & Sources
- University of Minnesota Extension. “Raised bed gardens.” Practical guidance on site prep, width limits, and drainage.
- University of Georgia Extension. “Raised bed materials.” Material safety for edible gardening.
- Royal Horticultural Society. “How to make a raised bed.” Fill levels, soil mix ratios, and structural reinforcement.
FAQs
What kind of wood should I use for an elevated bed?
Use pressure-treated lumber rated for ground contact, or naturally rot-resistant species like cedar or redwood. For growing food, confirm the treatment is safe for edible gardening. Cedar costs more but lasts longer without chemical treatment.
How tall should an elevated garden bed be?
Standard elevated beds sit 24 to 36 inches tall — high enough to work standing. Choose based on your comfort; someone who wants to sit while gardening can build shorter, around 18 inches.
Do I need a bottom on an elevated bed?
Yes — the bottom is what makes it elevated rather than just tall-sided. Use slats with small gaps for drainage, and add hardware cloth beneath the slats if burrowing pests are a concern. The floor also lets you place the bed on a patio or deck.