4 ways to build a raised bed for gardening
This story was originally published in April 2020.
If you’re late to the game and didn’t get a chance to reserve space at your local community garden, but have a little bit of yard space — or even a patio with a sturdy foundation — you can make your own raised bed.
Raised beds are containment units that have several square feet of growing space and anywhere between half a foot to several feet of depth. Because you control the soil composition in a raised bed, they allow you to grow wherever you are, whether you’re working on concrete or soil that simply isn’t arable.
Despite popular DIY aesthetics, there are certain materials that you should not use to make a raised bed. Railroad ties are one such example. Though they have that perfect rustic sheen, they are heavily treated with chemicals. The Environment Protection Agency has even released warnings regarding the use of railroad ties in gardens because of the high levels of toxic creosote they contain. Similarly, car tires are also often utilized as makeshift raised beds, but they should not be used for edible plants because they contain heavy metals that may leach into the surrounding soil.
Treated lumber can also leach harmful chemicals into your soil. For years, pressure treated lumber was created using chromated copper arsenate, which was found to release arsenic into the surrounding soil over time. Newer treated lumber instead uses copper azole and alkaline copper quat, which, though less toxic than arsenic, can still leach into soil.
Still, that leaves a number of options for people looking to make their own raised garden beds. Here are videos that will help guide you, no matter what material you want to use.
How to make a raised garden bed out of wood
Wood is probably the best choice for an easy, inexpensive DIY garden bed. In this handy instructional video, the infectiously-enthusiastic James Prigioni shows you how to build a raised garden bed using several two-by-tens and two-by-fours. When it comes to choosing wood, you have to consider cost versus durability. Douglas fir is a great, affordable option for a raised bed that will last about five and seven years before needing to be replaced. Redwood, cedar and black locust are all extremely rot-resistant and will last between 10 and 20 years, but they come at a much higher price point, between three to four times as expensive as Douglas fir.
How to make a raised garden bed out of cinder blocks
Cinder blocks make for extremely durable raised beds, though they require quite a bit more heft than other materials. If you’re physically fit and up to the challenge, check video from Oklahoma Gardening, a weekly television program produced by the Oklahoma Cooperative Extension Service. Host and Oklahoma State University consumer horticulture specialist Casey Hentges breaks down the process of building a raised bed from cinder blocks. As an added bonus, at the end she plants squash in her new raised garden bed and walks viewers through the process of properly transplanting squash seedlings.
How to make raised beds out of corrugated metal
When it comes to durability, you can’t do much better than metal. YouTube user homesteadonomics guides users through the process of building a metal raised garden bed with corrugated tin and redwood fencing to build sleek and durable raised beds (along with a jammin’ rock and roll soundtrack).
How to make a raised garden bed out of pallets
Wooden shipping pallets are plentiful and popular for DIY crafts, as long as you are wearing the proper safety equipment and know what you are doing when it comes to removing the wood from the strongly-secured joints. YouTube user A Thousand Words demonstrates the full process, from safely disassembling the pallet to filling the completed box and giving it new life as a raised garden bed.
Upcycling pallets comes with a few caveats, though. You should know where your pallets came from before you use them for gardening. Used pallets can often take on the remnants of whatever is shipped on them, including bacteria from food and chemicals from pharmaceuticals. Some older pallets were also treated with a chemical called methyl bromide, though the practice mostly stopped in 2005. Look for a stamp on the pallet that says “HT” for heat-treated, “KD” for kiln-dried or “DB” for debarked. If there is no stamp or the stamp reads “MB” — indicating that the pallet was treated with methyl bromide — do not use the pallet for your raised garden bed.