That’s a really thoughtful and important concern—you’re absolutely right to pay attention to what goes into the materials around your garden, especially when they’re in direct contact with the soil where you might grow food or where kids and pets play. Let me ease your mind a bit.
First, not all wooden outdoor benches are treated with toxic chemicals. In fact, many high-quality, natural wood benches are left completely untreated or are finished with non-toxic oils and sealants. For example, woods like cedar, redwood, and teak are naturally resistant to rot, insects, and moisture without any chemical treatment. These woods contain natural oils that protect them from the elements, so they don’t need the pressure-treated chemicals that often raise concerns.
Pressure-treated lumber is the main culprit when it comes to chemicals like chromium, copper, and arsenic (in older treatments) or copper azole (in newer ones). If your bench is made from pressure-treated pine or fir, there might be some leaching over time, especially if the wood is in constant contact with damp soil. However, modern treatments like ACQ (Alkaline Copper Quaternary) are significantly less toxic than older CCA (Chromated Copper Arsenate) treatments, though they still contain copper that can be harmful to soil microorganisms or edible plants if concentrated.
The best way to solve your worry is to choose the right bench or ask the manufacturer directly. If you’re buying from a reputable brand that uses FSC-certified, untreated hardwood (like cedar or black locust), you’re almost certainly safe. Some eco-friendly options even apply plant-based oils like linseed oil or tung oil for surface protection, which are food-safe and biodegradable. And if you already have a treated bench, you can always add a non-toxic barrier—for example, placing a large stone or plastic mat under the legs—to prevent direct soil contact.
So, yes, you can absolutely find gorgeous, durable wooden benches that are completely chemical-free and won’t leach anything into your soil. Just look for “untreated,” “natural,” or “eco-friendly” labels, or stick with hardwood species known for their natural durability. Your garden—and your peace of mind—will thank you.