Yes—an urban planter box can be mounted on a brick wall, but it should be treated as a structural project rather than a quick decoration. The key questions are how heavy the planter will be when fully planted and watered, what type of brick wall you have, and whether the wall can safely carry the load. A small, lightweight planter with shallow soil may work on a solid brick wall with the right anchors. A large, deep, or irrigated planter is much heavier and may require a structural engineer, especially if the wall is a veneer, cavity wall, or older brickwork.
Use the brick itself, not mortar joints, for anchor points. For solid brick or concrete, use corrosion-resistant masonry sleeve anchors, wedge anchors, or stainless-steel lag screws with approved masonry plugs. For hollow brick or block, use chemical anchors or hollow-wall masonry anchors rated for the load; drywall anchors are not acceptable. If the back of the wall is accessible, through-bolts with washers and backing plates are often stronger. Use stainless steel or hot-dipped galvanized brackets, bolts, washers, and screws.
A practical hardware checklist includes heavy-duty L-brackets or a French cleat system rated for the planter’s loaded weight; masonry anchors suitable for your brick type; stainless-steel bolts or lag screws; large washers and a steel backing plate to spread the load; waterproof sealant around drilled holes; drainage trays or spacers to keep moisture away from the brick; and, for larger planters, irrigation and overflow management.
Mounting tips: choose a lightweight planter or reduce soil depth; calculate the weight of soil, water, plants, and container; locate safe anchor points; drill carefully with a masonry bit; seal holes; use a spacer or standoff bracket for airflow and drainage; and check the installation periodically. If there is any doubt about the wall’s strength or the planter’s weight, consult a qualified contractor or structural engineer before drilling.