Yes, urban planter boxes can be securely attached to both brick walls and railings, provided the correct methods and hardware are used. For solid brick walls, the most reliable method is to use masonry anchors. You must drill pilot holes into the mortar joints or the brick itself (though brick can be brittle) and then use heavy-duty anchors like sleeve anchors or wedge anchors to fix a sturdy mounting bracket. The planter box is then attached to this bracket. It is crucial to ensure the wall can bear the significant weight, especially when the soil is wet.
For metal or wooden railings, the process is different but equally achievable. You can use heavy-duty adjustable railing brackets, U-bolts, or sturdy straps that clamp around the railing post or horizontal bar. The key is to select corrosion-resistant hardware (like galvanized or stainless steel) and to ensure the attachment points are tight and evenly distributed to prevent tilting. Always check the railing's stability first; it must be structurally sound.
Regardless of the surface, always prioritize safety. Consider the fully saturated weight of the planter, use a level during installation, and regularly inspect the fittings for loosening. With proper installation, your vertical garden will be both beautiful and securely anchored.