That's a creative idea, but the short answer is: it depends—mostly on whether the bench is yours or public property.
If the bench is public (in a park, on a sidewalk, or owned by a city or homeowner’s association), removing the backrest is almost certainly not allowed without official permission. Street benches are designed to be sturdy, safe, and accessible for everyone. The backrest provides support, especially for elderly people or those with mobility issues. Tampering with it could create a safety hazard, make the bench unstable, or violate local regulations. You could face fines or liability if someone gets hurt. Plus, many cities require benches to meet specific Americans with Disabilities Act (ADA) standards for seat height and depth. If you want a planter-look for a public space, it’s better to approach your local parks department—they may have a formal process for donating or replacing a bench with a planter-style version.
If the bench is your personal property (e.g., reclaimed from demolition or purchased from a salvage yard), you have more freedom. However, you still need to consider structural integrity. Benches are usually built as a single frame. Removing the backrest could weaken the whole structure, especially if the legs were connected to the back. In many traditional park benches, the backrest acts as a key brace. If you take it off, the bench may wobble or collapse when filled with soil and water. My advice: before cutting or unbolting anything, turn the bench upside down and check how the back legs and seat are joined. If they’re separate pieces that just bolt together, you can probably remove the backrest safely. If they’re welded or share a continuous metal frame, you’ll need to reinforce the seat base—for instance, by adding a wooden or metal cross-brace underneath.
For a planter look, you might achieve a cleaner effect by simply leaving the backrest off and placing a long, narrow planter box (lined with plastic to protect the wood) on the seat. That way, you keep the bench’s function and get the look you want—without risking structural failure or legal trouble. Good luck!