Galvanized and coated steel raised beds compared by the sizes, wall heights and soil capacity their makers publish, with what extension services say about zinc, lead and lifespan.
Metal beds are thin coated steel panels bolted into a frame, usually open at the bottom. Virginia Cooperative Extension says most are 20 to 24 gauge galvanized steel, and cites research that 14-gauge galvanized steel could last 35 to 50 years before it first rusts through. Several makers in our catalogue sell one kit that assembles in several layouts, so one kit can make a long narrow bed or a wider one; others sell fixed sizes.
Shown: 2 × 8 ft layout in Modern Gray.
For changing the layout of one bed
17 in tall · 6 to 35 ft³ · 9 sizes and layouts
Arrange the metal panels into a long, narrow bed or a wider growing space. One kit offers nine layouts with 17-inch walls.
Choose one layout before ordering soil: the nine arrangements use the same set of panels.
For compact modular layouts
15 to 29 in tall · 4.8 to 28.8 ft³ · 12 sizes and layouts
A Birdies steel kit that assembles in six layouts from 2 × 2 ft to 3 × 4 ft, 15 or 29 inches tall. Birdies sold it as the Small bed before renaming its sizes.
Choose the layout before measuring paths or buying soil. The six shapes are alternative layouts of one kit.
For a long, narrow steel bed in a fixed size
17 in tall · 18 to 70 ft³ · 3 sizes and layouts
Three fixed sizes of one 17-inch galvanized steel bed: 3 ft 4 in square, 8 ft 6 in long and 13 ft 4 in long, all 3 ft 4 in wide.
Choose by length; all three are 3 ft 4 in wide and 17 inches tall. Each stated capacity is larger than the published length × width × height, so measure the inside before ordering soil.
For a small bed with no assembly
12 in tall · 8 ft³ · 1 size
A one-piece galvanized oval with no bottom, 48 × 24 inches and 12 inches tall, which Tarter says holds 8 cubic feet. No tools or assembly are needed.
It arrives ready to place. Length and width can vary by up to 4 inches, the maker says, so measure it before planning paths.
For a tall steel bed in one size
24 in tall · 36 ft³ · 1 size
A powder-coated steel bed 72 × 36 inches and 24 inches tall, with no bottom panel. The maker states 36 cubic feet, or 269 gallons, of soil.
The 24-inch walls hold 36 cubic feet when full. You do not have to fill all 24 inches; choose your fill depth first.
For changing the layout of one bed
17 in tall · 6 to 41.5 ft³ · 17 sizes and layouts
One square-ended steel kit, 17 inches tall, that assembles into 17 layouts from 24 × 24 inches to 47 × 90 inches. The bottom is open.
Pick the layout first: only the two largest use every panel. The maker gives two different soil figures for the 24 × 70 inch layout, so measure that one before ordering.
For compact modular layouts
15 to 29 in tall · 5 to 29 ft³ · 12 sizes and layouts
Epic Gardening’s own steel kit in six layouts from 2 × 2 ft to 3 × 4 ft, 15 or 29 inches tall, with a limited lifetime warranty.
Choose the height first: each height is sold as its own kit. The 29-inch bed takes about twice the soil of the 15-inch one.
Shown: the Olive Green 6-in-1 kit.
For a smaller modular bed
17 in tall · 6 to 25 ft³ · 6 sizes and layouts
Fit a smaller garden with six panel arrangements, from a narrow rectangle to a compact square, all with 17-inch walls.
Place this open-bottom bed over garden ground. Choose an elevated planter if you need a contained growing space.
For a longer modular bed
15 to 29 in tall · 15 to 48 ft³ · 12 sizes and layouts
A Birdies steel kit with internal bracing, in six layouts up to 5 × 4 ft, 15 or 29 inches tall. Birdies sold it as the Medium bed before renaming its sizes.
The 4-foot-wide layouts need access from both long sides. Mark those paths before deciding which layout fits.
For a longer modular bed
15 to 29 in tall · 15 to 48.3 ft³ · 12 sizes and layouts
Epic Gardening’s steel kit in six layouts from 3 × 4 ft to 4 × 5 ft and 2 × 7 ft, 15 or 29 inches tall.
The 4-foot-wide layouts need access from both long sides. Mark those paths before deciding which layout fits.
For taller bed walls
32 in tall · 11 to 47 ft³ · 6 sizes and layouts
Choose among six layouts with taller, 32-inch metal walls. Set the growing depth separately to work out your soil order.
Filling all 32 inches takes substantially more material than a shallow fill. Enter your intended depth before buying soil.
For a round garden bed
15 to 29 in tall · 10 to 20 ft³ · 2 sizes and layouts
A round Birdies bed 39.3 inches wide, 15 or 29 inches tall. Birdies states 10 or 20 cubic feet of soil.
Leave a clear route around the rim so you can reach the center from different sides.
For the largest modular layouts
15 to 29 in tall · 20 to 87 ft³ · 10 sizes and layouts
Epic Gardening’s largest kit, in five layouts from 2 × 8 ft to 6 × 6 ft, 15 or 29 inches tall.
At 29 inches tall the 6 × 6 ft layout takes 87 cubic feet by Epic’s figures. Fill only the depth your plants need.
For a round garden bed
17 in tall · 14 ft³ · 1 size
A round Vego steel bed 42 inches across and 17 inches tall, open at the bottom. Vego states 14 cubic feet of soil.
Leave room to walk around it: from the edge, the center is 21 inches away.
For the largest modular layouts
15 to 29 in tall · 19.2 to 86.4 ft³ · 10 sizes and layouts
Birdies’ largest kit, in five layouts from 8 × 2 ft to 6 × 6 ft, 15 or 29 inches tall. Birdies sold it as the Large bed before renaming its sizes.
The 6 × 6 ft layout puts the middle 3 feet from every side. Check the reach you need before choosing it.
For a round garden bed
15 to 29 in tall · 9.9 to 19.7 ft³ · 2 sizes and layouts
Epic Gardening’s 38-inch round bed, 15 or 29 inches tall, taking 9.85 or 19.7 cubic feet by Epic’s manuals.
The round beds cannot be joined into a larger size, Epic says. Leave room to walk around the rim.
For the largest modular layouts
32 in tall · 40 to 96 ft³ · 10 sizes and layouts
Vego’s largest modular kit, 32 inches tall, in ten layouts from 2.5 × 6 ft (40 cubic feet) to 6 × 6 ft (96 cubic feet).
Vego says the 32-inch walls make gardening more comfortable. Filling them takes a lot of soil, so choose your fill depth before ordering; the deep-bed guide covers cheaper ways to fill the bottom.
For a tall steel bed with a wood look
26 in tall · 32.7 to 65.2 ft³ · 2 sizes and layouts
A steel bed with a wood-look finish, 26 inches tall, in 2 × 8 ft (32.7 cubic feet) or 4 × 8 ft (65.2 cubic feet). The bottom is open.
In the 4 × 8 ft size, the middle is 2 feet from either long side; the 2 × 8 ft size is half as wide. Check the reach you need before choosing.
Shown: 2 × 4 ft, Olive Green, without wheels.
For gardening at standing height
32 in overall · 7.6 to 15 ft³ · 3 sizes and layouts
Bring a 12-inch planting space up on legs, with a shelf below for supplies. Compare the footprints and wheeled options before choosing a spot.
Use the 12-inch planting depth for fill calculations. The taller overall stand height includes the legs.
Shown: 1.5 × 5.5 ft, Olive Green, without wheels.
For a narrow elevated planter
32 in overall · 5.2 to 8.3 ft³ · 2 sizes and layouts
Add a long growing space where a wide planter would crowd the path. The narrow bed sits on legs with storage below.
Vego gives conflicting fill capacities. Measure the inside and use the soil calculator before ordering bags.
Shown: 3 × 8 ft, Olive Green, with wheels.
For a long elevated planter
32 in overall · 22.6 to 23.3 ft³ · 2 sizes and layouts
Choose a long planter on legs with 12 inches of planting depth. Compare the different footprints and caster options for your garden.
The wheeled and fixed options have different footprints. Choose the version first, then mark its space and access paths.
The University of Minnesota Extension says zinc from the coating may leach into the soil only in highly acidic soil, below pH 5; if zinc concerns you, it suggests a liner or stainless steel. It also warns that some prefabricated metal beds sold online have been found to contain lead. The safety guide has the details.
Tall metal walls do not mean you must fill them. Most crops need at least 10 inches of soil, according to UGA Extension; the depth guide gives depths by crop, and the deep-bed guide covers filling a 32-inch bed without buying all that soil.