Why a Raised Bed?

• Better soil control: Build a loose, fertile mix ideal for vegetables.
• Improved drainage: Helps prevent waterlogging and root rot.
• Warmer, earlier soil: Extends the season in many climates.
• Fewer weeds and easier maintenance: Defined space, less compaction.
• Accessibility: Higher sides reduce bending; adjust height for comfort.

Plan Your Bed

Location

• Sun: Aim for 6–8+ hours of direct sunlight daily for most vegetables.
• Water: Place the bed within easy hose reach or install drip irrigation.
• Ground: Choose a relatively flat, well-drained spot. Avoid tree roots (they will invade).
• Wind: In windy areas, consider a windbreak or lower-profile crops.

Size and Height

• Width: 3–4 ft max so you can reach the center from both sides without stepping in.
• Length: 4–12 ft is common. A classic is 4 ft × 8 ft (1.2 m × 2.4 m).
• Height: 11–12 in (using nominal 2×12s) is great for most crops; 18–24 in is ideal for accessibility or poor native soil.
• Aisles: Leave 18–24 in between beds (at least 36 in if using a wheelbarrow).

Orientation

North–south orientation maximizes sun on both sides. If using a trellis on the north edge, it won’t shade shorter crops.

Materials and Tools

Recommended Materials

• Lumber (choose one):
  • Cedar, redwood, or black locust (naturally rot-resistant, long-lasting).
  • Standard construction lumber (budget option; shorter lifespan).
  • Modern pressure-treated lumber (ACQ or CA): Widely considered safe for vegetable beds by many university extensions since 2004-era formulations; avoid old CCA-treated wood. Optionally staple a heavy-duty plastic liner (HDPE) on the inside walls to minimize soil contact.
  • Metal bed kits or galvanized steel panels (durable; check for sharp edges).
• Fasteners: Exterior-grade or stainless deck screws (#8 or #10), 2.5–3 in.
• Corner reinforcement:
  • 4×4 posts for the corners (optional but sturdy), or
  • Metal corner brackets/plates.
• Rodent barrier (optional but recommended): 1/2 in galvanized hardware cloth for the bed bottom.
• Weed barrier (optional): Permeable landscape fabric beneath the bed perimeter only (avoid lining the entire bottom if drainage is poor).
• Soil components: Blended composts, topsoil or raised bed mix, and texture amendments (perlite/vermiculite/coco coir).
• Mulch: Straw, shredded leaves, or arborist chips for pathways and bed surface.
• Irrigation (optional): Soaker hoses or drip line with a timer.

Tools

• Drill/driver with bits
• Circular saw or hand saw (get cuts done at the store if you prefer)
• Measuring tape, square, pencil
• Level and stakes/string for layout
• Work gloves, eye protection, dust mask when cutting/sanding
• Shovel, rake, wheelbarrow
• Staple gun (for hardware cloth/liner)

Example Build: 4 ft × 8 ft × 11.25 in Cedar Bed

Cut List

• 2 × 2×12s at 8 ft (no cut)
• 2 × 2×12s at 4 ft (cut from an 8 ft board)
• Optional: 4 × 4×4 corner posts at 11.25 in high (flush with rim) or 16–24 in if you want to sink them into the ground for anchoring

Hardware

• 24–32 exterior deck screws, 3 in
• Staples for hardware cloth, 1/2–3/4 in
• Galvanized hardware cloth: ~5 ft × 9 ft piece

Site Prep

1. Mark the footprint with stakes and string.
2. Remove sod or mow very short. Rake smooth. Lightly loosen the top 2–3 in of soil to encourage drainage.
3. If rodents are a concern, lay hardware cloth over the area and secure it with landscape staples; overlap seams by at least 6 in.
4. Optional: Lay landscape fabric only under the bed perimeter to discourage weeds creeping in from the edges.

Build the Frame

1. Pre-drill screw holes 3/4 in from board edges to prevent splitting.
2. Attach the 4 ft end boards to the inside of the 8 ft side boards with two or three 3 in screws per corner, creating a rectangle.
3. For extra strength, install 4×4 corner posts inside each corner. Drive screws through the side boards into the posts.
4. Check for square: measure diagonals; adjust until both diagonals are equal.
5. Set the frame in place. Use a level and shim or remove soil until it sits level in all directions (critical for even watering).
6. Staple hardware cloth to the bottom edges of the frame if used, pulling taut.
7. Optional: Line the inside walls (not the bottom) with heavy-duty plastic (HDPE) to protect wood from constant moisture.

Fill With a Productive Soil Mix

Great soil is the engine of a raised bed. Avoid filling with straight topsoil or pure compost. Blend for structure, nutrition, and drainage.

Volume Calculation

Volume (cubic feet) = Length × Width × Height. For 4 × 8 × 0.94 ft (11.25 in): 4 × 8 × 0.94 ≈ 30 cu ft. There are 27 cu ft in a cubic yard, so you need about 1.1 cubic yards.

Soil Mix Options

• Balanced Raised Bed Mix (by volume):
  • 40% high-quality topsoil or screened loam
  • 40% diverse composts (blend at least 2–3 sources, e.g., plant-based, mushroom, worm castings)
  • 20% aeration/structure (perlite or pumice) and water retention (coco coir). If using peat moss, pre-wet thoroughly and consider sustainability; coco coir is a renewable alternative.
• “Mel’s Mix” style: roughly 1/3 compost, 1/3 peat/coir, 1/3 vermiculite (coarse). Add supplemental minerals if needed.

How to Fill

1. Mix components on a tarp or in a wheelbarrow until uniform.
2. Fill the bed to the top; it will settle 10–15% after watering.
3. Water thoroughly to settle the mix; top up if needed.
4. Incorporate an organic, balanced fertilizer per label (e.g., 4-4-4) before planting.
5. Mulch the surface 1–2 in with straw or shredded leaves to reduce weeds and evaporation.

Target pH for most veggies: 6.2–7.0. If unsure, test the soil and amend with lime (to raise pH) or elemental sulfur (to lower pH) per test recommendations.

Irrigation and Watering

• Soaker hoses: Snake one or two lengths across the bed and cover with mulch.
• Drip irrigation: Lay 1/2 in poly header with 1/4 in drip lines. Use an automatic timer for consistency.
• Hand watering: Water deeply and less often. Aim for ~1 in per week total, more in heat; adjust for rainfall.

Optional Add-Ons

• Trellis: Install a sturdy trellis on the north side for peas, beans, cucumbers, or tomatoes. EMT conduit or cattle panel works well.
• Hoop house: Add 1/2 in PVC or metal hoops and cover with frost cloth or insect netting for season extension and pest control.
• Critter fence: Short mesh panels around the bed deter rabbits and pets.
• Row covers: Lightweight fabric protects seedlings from insects like flea beetles and cabbage moths.

Planting Tips

• Group plants by height and sun needs. Tall trellised crops on the north side; shorter greens in front.
• Use spacing appropriate for raised beds (often closer than in-ground). Follow seed packet guidance.
• Practice crop rotation annually (e.g., move nightshades, brassicas, legumes) to reduce disease and pest build-up.
• Interplant fast crops (radishes, lettuce) between slower ones (tomatoes, peppers) to maximize space.
• Succession sow every 2–3 weeks for continuous harvests of greens and roots.

Maintenance Checklist

• Weekly: Check moisture, weeds, and mulches; inspect for pests under leaves.
• Monthly: Top-dress with compost around heavy feeders; prune and trellis as needed.
• Seasonally: Add 1–2 in of fresh compost between crops. Re-mulch paths to suppress weeds.
• Annually: Test soil every 1–2 years and adjust pH and nutrients as recommended.
• Wood care: Brush off soil contact from sides, keep mulch a few inches from wood to prolong life.

Safety and Sustainability Notes

• Wear eye protection and a dust mask when cutting/ sanding wood.
• If using pressure-treated lumber, confirm it’s modern ACQ/CA and not old CCA. Avoid burning any treated wood scraps.
• Do not use railroad ties (creosote) in vegetable beds.
• Source compost from reputable suppliers; avoid biosolids if you prefer food-only inputs.
• Collect leaves and grass clippings (chemical-free) to build your own compost for long-term fertility.

Troubleshooting

• Poor drainage: Ensure bottom is open and soil is loose; add coarse perlite or build slightly higher. Avoid lining the entire bottom with plastic.
• Soil settling: Normal in the first season. Top up with compost/soil mix.
• Rodents tunneling: Install hardware cloth under the bed; ensure overlaps are stapled and edges secured.
• Boards bowing: Add mid-span stakes or interior cross-brace; use thicker lumber (2×12) for long sides.
• Plants yellowing: Check watering first; then consider nitrogen deficiency—side-dress with compost or organic nitrogen.

Cost and Sourcing Tips

• Lumber: Compare local yards vs. big-box stores; look for “construction common” cedar as a value option.
• Soil/compost: Bulk delivery is cheaper than bags for 1+ cubic yard. Split an order with neighbors.
• Hardware: Buy exterior screws in contractor packs for better pricing.
• Repurpose: Food-safe IBC totes, stock tanks, or untreated pallets (HT-stamped) can become planters with drainage holes.

Quick Build Summary

1. Choose a sunny, level site near water.
2. Cut and assemble a 4×8 ft frame from 2×12s; square and level it.
3. Install hardware cloth under the bed for rodent protection (optional).
4. Fill with a blended raised bed mix (~30 cu ft) and water to settle.
5. Add irrigation and mulch; plant by height and spacing; trellis tall crops.