Start by resisting the urge to wipe it off. That usually pushes gum deeper into the surface and makes a bigger mess. The safest approach is to make the gum cold and brittle, then lift it away gently.
For most urban outdoor furniture—benches, tables, railings, and planters—begin with ice. Put a few ice cubes in a sealed plastic bag and hold it against the gum for several minutes. If you’re maintaining a public space, a commercial aerosol gum remover can also work well because it freezes the gum quickly. Once the gum feels hard, scrape it upward with a plastic scraper, an old credit card, or a stiff plastic edge. Avoid metal scrapers, wire brushes, and knives; they can scratch powder-coated metal, plastic, and painted wood.
After the main lump is gone, deal with the residue. For nonporous surfaces such as metal or plastic, dab a cloth with rubbing alcohol and test a small hidden spot first. For wood, use as little moisture as possible and avoid soaking the surface. A citrus-based cleaner can help on some materials, but test it first because it may affect finishes. Skip peanut butter or oil on porous public furniture unless you can clean it thoroughly afterward—there’s a real risk of staining and leaving an oily patch.
On concrete or stone, freeze and scrape first, then scrub the remaining film with a mild soap solution and a stiff nylon brush. A pressure washer can help on durable concrete, but keep it at low pressure and don’t blast near joints, paint, or nearby plants. If the gum is soft and fresh, hot water can sometimes help lift it, but cold is usually cleaner because it stops the gum from spreading.
Finish by washing the area with mild soap and water, then dry it. Wear gloves, dispose of the gum in a trash bin, and keep solvents away from drains, soil, and plants. If the furniture has an unknown finish, test any cleaner on a hidden spot first. With a little patience, the gum should come off without damaging the furniture.