Vegetables

What a raised bed costs in lumber, soil, and mesh

Board count and soil volume for a 4-by-8 bed in Western clay, plus hardware cloth for voles. Price the tags yourself.

By the Thin Air Harvest editorial team. Updated November 1, 2026.

A 4-by-8 bed, 10 inches deep, holds 26.7 cubic feet of mix. That is just under 1 cubic yard.

The boards are the smaller decision. The soil is the load, the bill, and the thing people under-buy, then fill the gap with peat that sheds water the first time a chinook dries it. This page is the takeoff.

The raised bed design page is why the bottom stays open and why you do not work clay wet. Multiply the lines by the price at your yard. A national dollar figure would be stale before the garlic goes in.

The boards

For a 10-inch inside height, two stacked 2x6s work, or one 2x12 if you can find a straight one. A 4-by-8 rectangle needs two 8-foot sides and two 4-foot ends. In 2x6 stock that is four 8-foot boards if you cut the ends from the offcuts carefully, or three 8-foot boards plus one 8-foot ripped… do not get clever.

Buy four 8-foot 2x6s for the first course and four more for the second course if you stack. That is eight boards for one bed, 10 inches tall, with a little waste at the corners where the joint overlaps.

Untreated rot-resistant lumber, or plain pine you expect to replace, belongs in a vegetable bed. Railroad ties and unknown salvaged treated wood do not. Steel corners or a couple of screws per joint are enough.

A painted decorative kit is a different purchase. It still has to hold a yard of wet soil, which is heavy. If the corner bracket looks like it belongs on a bookshelf, it will open in July.

Height beyond 10 or 12 inches is a want, not a crop need, unless you are growing long carrots and you did not loosen the native soil. Every extra course is more lumber and more mix, and in this wind it is more wall for the air to dry.

The design page already said a tall box is a wick. Price that before you build a waist-high planter because your back prefers it. A 16-inch bed is about 42.7 cubic feet, or 1.6 cubic yards. That is the real cost of the extra height.

The fill

One cubic yard is the order for a 4-by-8-by-10-inch bed, with a little left for settling. Two beds are two yards. Do not buy “bed mix” that is mostly peat and perlite.

It repels water after it dries, and it will dry. A workable blend is on the order of two parts loam or your best topsoil to one part finished compost.

If the native soil at the bottom of the hole is decent once you loosen it, you need less imported soil than the box suggests. Loosen 6 to 8 inches under the frame, then fill.

Finished compost means it does not heat and it does not smell of ammonia.

Fresh manure under carrots forks the roots and under potatoes encourages scab.

That warning is on the roots page. If a soil test shows high salts, pause the manure even if it was free. Free fill that salts the bed is expensive.

Delivery is often the line item people forget. A yard that fits in a car does not exist. A pickup takes a partial yard if you do not want to bury the axle.

Two beds may justify a delivery fee that one bed does not. Write the fee on the takeoff. It is part of the soil price.

Hardware cloth, only if you need it

CSU’s mountain fact sheet says to put quarter-inch hardware cloth under a bed to keep voles and pocket gophers out, stapled to the bottom before the soil goes in. A 4-by-8 bed is 32 square feet, plus overlap at the edges, so buy a roll that covers about 40 square feet once you stop pretending you will cut perfectly.

If you have never seen a vole runway in the yard, you can skip the mesh and add it later. Mesh does not replace an open bottom. Water still has to leave. Do not lay plastic under the cloth.

For an in-ground bed, the same sheet says dig 1 foot for greens and 2 feet for roots, line the bottom, and put the soil back. That is more digging and less lumber. It is the right choice when the native soil is usable and you are fighting gophers, not clay you refuse to stand on.

A two-bed takeoff

The drip parts, filter, and regulator are on the drip parts page. Do not buy them as an afterthought in July when the bed is dust four inches down. Lay the line before you mulch.

What people overbuy

Cap stones, lattice, and a built-in bench double the lumber and do not grow a carrot. A tall cedar planter on a deck, with a solid bottom, is a container. It needs a drainage hole and a saucer plan, and it will dry faster than a bed on the ground.

If the only sunny spot is a deck, build that container and water it on its own schedule. Do not call it the same project as a bottomless frame on loosened clay.

Stain and sealant on the inside face are a waste and a question you do not want in the soil. Leave the inside raw. The outside can weather to the color of the fence. In this sun it will, quickly.

Checklist

• Compute volume before you fall in love with a tall box. A 4x8x10-inch bed is about 1 cubic yard.
• Buy eight 8-foot 2x6s for one stacked bed, not a mystery kit with thin corners.
• Loosen the native soil and use a mineral mix plus finished compost. Skip peat-only fill.
• Add quarter-inch cloth only where voles or gophers are already a fact.
• Keep the bottom open to the ground.
• Put delivery on the list.
• Price it at your yard. The table is the quantity. The receipt is the cost.

Sources

• CSU Extension, Vegetable Gardening in the Mountains, hardware cloth under beds and the organic-matter gap in mountain soils.
• CSU Extension, Colorado Vegetable Guide, on low organic matter and on why imported “soil” still has to drain.
• The volume figure is arithmetic: 4 feet times 8 feet times 10/12 foot, divided by 27, equals about 0.99 cubic yard.