With the Bloomers Rail Planter, you can enjoy harvesting herbs, vegetables, and flowers even if you live somewhere with limited space. The Bloomers Railing Planter is designed for dimensional lumber, metal, and plastic railings that are 1.25” to 3.875” wide (2×1 and 2×4 railings traditionally). The larger interior rail recess measures 3.5″ at the upper dimension and 4″ at the opening. Just insert at the desired spacing and gently pound in with a rubber mallet. You can further secure the planter with tie downs, bungie cords. Made from durable polyethylene resin, this planter can withstand any weather conditions and won’t crack. And because it’s HDPE, it is BPA free and perfectly safe to contact edibles at it does not contain, nor ever leach, harmful chemicals. Additionally, the drainage holes at the bottom of the planter allow deep, plant roots to breathe and prevent stagnant water from accumulating.