Research confirms growing vegetable and herb gardens in raised beds built with preserved wood is completely safe

 

Researchers at Oregon State University have confirmed it is safe to grow vegetables and herbs in raised beds built with preserved wood. Chemicals from the wood preservative will not migrate through the soil and contaminate the plants, as some have suggested.

An easy, inexpensive DIY project for a weekend afternoon, preserved wood raised beds are customizable, will last decades and won't harm your plants.

...plants grown in garden boxes made with preserved wood do not absorb any preservative chemicals from the wood... those concerns are unwarranted.”

— Gerald Presly, PhD., assistant professor, Oregon State University

VANCOUVER, WA, UNITED STATES, March 17, 2025 /EINPresswire.com/ -- With spring rapidly approaching, our attention is being pulled outdoors to the yard and garden projects we’ve been planning while waiting out the winter months.

Those considering planting a vegetable or herb garden will be pleased to learn that building a raised bed garden box using preserved wood is one of the simplest do-it-yourself projects imaginable. It requires only a few items easily found at the local home center or hardware store and a few tools most gardeners (or gardeners -to-be) already own. Using preserved wood is a perfectly safe way to grow vegetables and ensures the raised bed will last decades.

Preserved wood, sometimes called "pressure-treated wood," is impregnated with preservatives that deter wood-destroying insects and the microorganisms found in soil that cause wood to rot. Most preserved wood is guaranteed to last 25 years or more when used properly.

There is no reason to be concerned the preservatives might migrate from the wood and contaminate plants growing in the beds. Researchers at Oregon State University released a study in 2024 that compared plants and vegetables grown in garden boxes made with preservative-treated and untreated wood. Over two growing seasons the researchers analyzed vegetables, herbs and plants, as well as soil samples, from both box types and found the copper levels (the active ingredient in preserved wood intended for residential use) were indistinguishable from one another, regardless of which box type the samples came from. “That tells us conclusively that plants grown in garden boxes made with preserved wood do not absorb any preservative chemicals from the wood,” said Gerald Presley, Ph D., an assistant professor at OSU and lead researcher on the project.

“Our results confirm without doubt that safety concerns about growing vegetables in beds built with preserved wood are unwarranted,” Presley stated. The researchers continued the study into a third growing season and got the same results. “The only difference we observed between the two box types is that, by the third growing season, the untreated wood boxes had begun to show significant signs of decay,” he reported.

Building a simple raised bed takes only a few hours and just about anyone, even those with little or no woodworking experience, will find it is not difficult. They likely also will save money. Out-of-pocket cost for the materials often will be less than the price of a similarly sized pre-built garden box (which might not last as long as the home-built preserved wood box) . DIY garden boxes also can be customized to perfectly fit the space and personal preferences. The materials — preserved wood, proper fasteners and off-the-shelf end-treating preservative — are readily available at virtually any home center or neighborhood hardware store and the tools required probably are already on hand. Unlike the untreated boxes used in the OSU study, once it’s been built with preserved wood, it won't need to be rebuilt for decades.

Details about the OSU study and its findings can be found in a Western Wood Preservers Institute (WWPI) publication PreserveTech: Safe Garden Boxes Using Preserved Wood, available online at https://wwpi.info/PT-GardenBoxes. A summary of the study from the OSU Extension Service is available at https://wwpi.info/OSUGardenBox.

NOTE TO EDITORS: To include written instructions for building a simple, rectangular raised bed, use the link for photos and captions provided below.