Standard planters from our planter box factory are not all one fixed depth. Our most common standard depths are 12, 15, and 18 inches, and 18 inches is our standard shrub-ready option. So if you need at least 18 inches for shrub root growth, yes, our standard line can meet that requirement. For larger shrubs, we recommend moving up to 24, 30, or 36 inches, which we can produce as custom or semi-custom planters.

Depth alone, however, does not guarantee healthy roots. Shrubs also need enough width, volume, drainage, and a suitable soil mix. An 18-inch-deep planter works well for many compact and medium shrubs, including boxwood, dwarf hydrangea, and smaller azalea varieties, provided the planter is wide enough and drains freely. If the shrub arrives with a deep root ball or is expected to mature large, a 24-inch or deeper planter gives more room and reduces stress.

At our factory, we can confirm the best depth once we know the shrub type, mature size, and root-ball dimensions. If you want to stay with a standard planter, choose the 18-inch depth. If you need more than 18 inches, ask for a custom planter box built to 20, 24, 30, or 36 inches. We also factor in drainage holes, feet or spacers, liners, and weather-resistant materials. In short: our standard planters include 18-inch-deep models suitable for many shrubs, and deeper custom sizes are available when 18 inches is not enough.