The intuitive answer might be "yes," but the reality of watering taller versus shorter urban planter boxes is more nuanced. While height is a factor, it's not the sole determinant of watering frequency. The primary driver is the soil volume-to-surface area ratio. A taller, narrower planter has less soil surface exposed to air, which can actually reduce top-layer evaporation compared to a wide, shallow box of the same volume. However, the increased soil depth in a tall planter creates a moisture gradient: the top may dry quickly, while the bottom can remain soggy, risking root rot if overwatered.
Key factors influencing watering needs include material (porous terracotta dries faster than plastic), drainage, plant type, sun exposure, and climate. Taller planters often require deep, less frequent watering to ensure moisture reaches the lower roots, encouraging healthy growth. Shorter boxes may need more frequent, lighter watering as they dry out uniformly and faster. The best practice is to check soil moisture 2-3 inches deep before watering, regardless of planter height. Using moisture-retentive soil mixes and mulch can significantly reduce watering frequency for all container types. Ultimately, observing your plants and soil is more reliable than relying on planter height alone.