Wooden Raised Garden Beds Have Some Disadvantages All Gardeners Should Know About

When you decide to build a garden from scratch, you'll quickly find yourself facing some big decisions. For one, should you plant in the ground or build raised beds? And if you go with raised beds, what material should you use? Raised wooden garden beds are popular, but they also have disadvantages that any gardener should keep in mind before building — like their limited lifespan.

Raised beds can, in general, be expensive to build, making lifespan an important consideration. Wood is one of the most affordable materials to use for a raised bed compared to metal, stone, or brick, which is partly why it's so popular. But if you use rot-resistant wood such as cedar or redwood, you'll still be making a significant investment, and it will succumb to decay much sooner than a stone or a galvanized steel raised garden bed.

Wood has some other downsides, too. It requires regular maintenance if you want to get as much usage out of it as possible. It can change the pH of the soil, attract certain pests, and may be prone to cracking, warping, and other issues. That said, wooden beds can still be a worthwhile option for many gardeners as long as you keep these disadvantages in mind.

Wood is a natural, often sustainable material choice — and like all natural materials, it eventually breaks down. Wood that has not been chemically treated to increase its rot- and pest-resistance can break down in just a few years; fir is one example. Many gardeners recommend using naturally resistant woods like cedar and redwood. These are more durable but will still decay within a decade or two. In comparison, steel beds can last for several decades, and stone and brick beds may never have to be replaced again in your lifetime.

Using treated wood gives you an option to prolong durability, but it's not ideal. The chemicals used for treatment may leech into the soil, and the safety level depends on the type of chemical the wood was treated with. These compounds can also be absorbed into your body as you build the raised garden bed and work in the soil. If you're using treated wood for a garden bed, add a proper barrier to protect the growing medium. Recycled wood is also an option for building raised beds on a tight budget, but it may or may not be treated, so it should be used with caution and only for ornamental plants.

Regardless of what type of wood you use, regular maintenance is necessary to prolong the lifespan of the raised beds. Some wood species are prone to cracking, splitting, splintering, or warping, and the material can easily get dented or scratched, requiring repairs. Even rot-resistant woods will last longer with some type of treatment or preservative, and these may need to be reapplied regularly as they wear away in the elements.

Wood is vulnerable to damage caused by certain pests, such as termites. This raised bed material attracts slugs to your garden, too. They're drawn to decomposing organic material, including wood, and even intact wooden raised beds are more slug-prone because of the way the wood holds onto moisture. Lastly, some types of wood can change the pH of the soil. Cedar, hemlock, and other softwoods, for example, will make the soil more acidic over time due to the natural oils in the wood. If your plants prefer neutral or alkaline soil, you'll have to add amendments such as lime to balance it out.

Some disadvantages apply to all raised beds, not just wooden ones. The soil dries out more quickly than in in-ground gardens, so raised beds require more frequent watering. This means that nutrients drain out of the soil faster and fertilizer must be applied more often.

All that said, if in-ground gardening isn't an option and you're on a budget, the downsides of wooden raised beds shouldn't stop you from pursuing your gardening dreams. Wood is also a worthwhile choice for those who don't need the most durable beds, like if you rent your home rather than own it or if you don't mind replacing the beds down the line. But if you want the most long-lasting, pest-proof raised garden bed possible and you can afford it, you can't go wrong with stone, brick, or steel.