Materials. Kevin Espiritu, founder of Epic Gardening, generally recommends buying metal raised beds over wooden beds. “When you do the longevity calculation for metal versus wood, metal outperforms wood,” he says. "And during the pandemic, the cost of wood has skyrocketed, so sometimes wood is even more expensive than metal." He notes that good metal beds will last more than a decade with proper care, which includes making sure the bed doesn't frequently flood or sit constantly in moisture. And cover it with geotextile fabric or landscape fabric if you're growing crops that require acidic soil, which will corrode the metal.
Size. Beds should be at least a foot high, says Josh Singer, a community garden specialist with the D.C. Department of Parks and Recreation. "Larger crops like tomatoes and squash need at least that much room for their roots to grow," he says, adding that you can even dig another foot of soil under the bed so the plants have room to spread. . To make sure he can easily reach the entire bed, and that it's not so long that the sides buckle, he recommends keeping beds two to four feet wide and four to eight feet long.
Beauty. “In urban and suburban areas, you probably only have a backyard or small yard, so you probably want to like what you're seeing,” says Tim Williams, operations manager at Greenstreet Gardens, a landscape and design company. “But if beauty isn't a factor for you, don't worry. No one is going to judge you."
Assembly. “It's smart to have gloves on hand,” says Espiritu. “I always assemble the kits using a drill with a screwdriver bit, set to low torque, so I don't over-tighten the bolt or remove it, because it's faster. And have someone with you to help with the build. It will just be easier. Don't forget to make sure your bed is on level ground, because a raised bed on a slope will have unbalanced moisture distribution and can leach soil. (Have a level handy if you don't feel comfortable looking at it.)
Cost. Last but not least, consider your budget. A metal raised bed kit can cost several hundred dollars, plus shipping if it's not available locally. However, the good news is that by this time of year, many kits will be on sale or on clearance in the D.C. area. “But don't wait too long, because they will no longer be available and it will be too late to plant most things,” says Williams.
Here are four raised bed kits that the experts recommend.
Vego Garden’s 17-inch six-in-one modular metal raised bed. If you've been searching for raised bed options on Instagram, you've probably seen these eye-catching beds with rounded corners. Williams is a fanatic. “It's fantastic how much acreage you can get and how much soil volume you can get for deep root systems,” he says. The 10-piece kit with 17-inch-high sides can be built in six configurations, both square and rectangular, including 2-by-2-foot and 5-by-3½-foot. It takes about 35 minutes to assemble. When laying out the panels in this kit and the others, make sure the top and bottom are aligned; just flip the panel if not.
Birdies’ tall modular raised bed. The original of corrugated raised beds, Australia-based Birdies has been producing them for over 13 years. Made of galvanized steel with an Aluzinc coating, the bed can be built in nine configurations, rectangular and square, such as 40 by 24 inches and 66 by 40 inches. It's 29 inches tall, so you don't have to bend down to reach your plants, Espiritu says, "which is great for gardeners who are elderly or have accessibility issues." Reserve about 45 minutes to build and install it.
Olle’s 17-inch 12-in-1 galvanized raised bed. The panels are made from galvanized steel and coated with Aluzinc, designed to reflect the sun and maintain a constant ground temperature. The 12-piece 17-inch-tall panel kit can be converted into a dozen configurations, both rectangular and square, including 80-by-40-inch and 44-by-24-inch; It should take about 35 minutes to assemble. Singer likes this kit for its durability and height. When it comes to filling it, he recommends a mix of 90 percent topsoil and 10 percent compost; the latter will decompose throughout the year. "Dump a couple of bags of compost on the bed at the beginning of each year to freshen up the organic matter," he says. "And since the soil compacts, you really have to till it well every year."
Forever raised beds. “If you want a bed that isn't made of wood but lasts a long time and looks like wood, this is the way to go,” says Espiritu. Designed to appear to be built from cedar planks, these beds are made from a composite of recycled wood and plastic. They are available in 3-by-3-foot or 3-by-6-foot configurations, making them ideal for small backyard gardens. Expect it to take around 15-20 minutes to assemble.
Martell is a writer based in Silver Spring, Maryland. His website is nevinmartell.com. Find him on Twitter and Instagram: @nevinmartell.