I need a raised bed to fill with garden level soil before I can plant first season plants. I purchased some kits made from untreated wood - they were cheap and easy to assemble - and packaged them with a combination of bagged soil and composted kitchen scraps.
It only took me a few years to regret my choice. The side panels were bent, and the planks that lay on the ground were rotting. The rich loam inside began to spill out onto the white cobblestone paths around the bed, an eyesore and waste. This spring, I removed them and replaced them with three new raised beds and an herb garden on wheels, but first I spoke with three gardening experts and spent a lot of time researching my options.
Material. Buying a metal raised bed is generally recommended rather than a wooden one. "When you calculate the lifespan of metal versus wood, metal beats wood," he said. "And the cost of wood has skyrocketed during the pandemic, so sometimes wood is even more expensive than metal." He noted that a good metal bed can last for more than a decade with proper maintenance, which includes making sure the bed doesn't flood often or always in a humid environment. If you grow crops that require acidic soil, line them with geotextiles or landscape fabrics, which can corrode the metal.
size. Beds should be at least a foot high, says Josh Singer, a community garden expert with the Washington, D.C. Department of Parks and Recreation. "Larger crops, like tomatoes and squash, need at least that much room to grow their roots," he says, adding that you can even dig an extra foot under the bed to give the plants room to expand. To make sure you can easily reach the entire bed—and that the length isn't so long that the sides curve outward—he recommends keeping the bed 2 to 4 feet wide and 4 to 8 feet long.
beauty. "In cities and suburbs, you might just have a patio or a small yard, so you might want to like what you see outside," said Tim Williams, operations manager at Greenstreet Gardens, a design firm. "But don't worry if being pretty isn't your thing. No one's going to judge you."
assembly. "It's smart to have gloves on hand," Espiritu said. "I always use a drill bit assembly kit with a screwdriver bit - set to low torque so you don't over-tighten the bolts or strip it - because it's faster. And have someone with you to help build. It's just easier." Don't forget to make sure your bed is on flat ground, as raised beds on slopes can cause uneven moisture distribution and possible soil leakage. (If you are not comfortable with visual inspection, have a spirit level ready.)
cost. Last but not least, consider your budget. A metal loft bed kit can cost hundreds of dollars, plus shipping if not available locally. The good news, though, is that by this time of year, many of the kits will be on sale or clearance in Washington, D.C. "But don't wait too long because they'll become unavailable and it's too late to plant most things," Williams said.
Here are several loft bed kits recommended by experts.
17" 6-in-1 modular metal loft bed from olleGarden. If you've been browsing booster bed options on Instagram, you've probably seen these striking beds with rounded corners. Williams is a fan. "It's amazing how much surface area and large soil volume you can get for a deep root system," he said. The 17-inch-tall 10-piece kit can be built in six configurations, including square and rectangular, including 2x2 feet and 5x3½ feet. It takes about 35 minutes to assemble. When installing panels from this and other kits, check that the top and bottom line up; if not, just flip the panels.
Olle's 17" 12-in-1 galvanized loft bed. The panels are made of galvanized steel with an Aluzinc coating designed to reflect sunlight and maintain a consistent soil temperature. The 12-piece kit of 17-inch high panels can be converted into more than a dozen configurations, including rectangular and square, including 80x40 inches and 44x24 inches; assembly takes approximately 35 minutes. Singer loves this kit for its durability and height. When filling, he recommends using 90 percent topsoil and 10 percent compost. The latter will break down within a year. "Pour a few bags of compost into the bed at the beginning of each year to renew the organics," he said. "And because of soil compaction, you really have to farm it well every year."
A bed that is always raised. "If you want a bed that's not wood but will last a long time and look like wood, this is the way to go," Espiritu said. The beds are designed to appear to be constructed from cedar planks, made from recycled wood and plastic. They are available in 3x3ft or 3x6ft configurations and are perfect for smaller backyard gardens. Expect assembly to take about 15 to 20 minutes.
