Urban planter boxes bring greenery to city balconies, rooftops, and patios, but not all plants thrive in these confined spaces. Choosing the wrong type can lead to disappointment, wasted effort, and even damage. Here are key plant types best avoided for successful urban container gardening.
First, avoid planting large trees or shrubs destined for significant growth, such as oak, maple, or large ornamental shrubs. Their extensive root systems quickly become pot-bound, stunting growth and requiring constant repotting. The sheer weight and size of a mature root ball can also pose structural risks on balconies.
Deep-rooted vegetables are another poor choice. Plants like standard corn, full-sized potatoes, parsnips, and large pumpkins require more soil depth and volume than typical planter boxes can provide. This results in stunted, unproductive plants and a disappointing harvest. Opt for compact, dwarf, or "bush" varieties instead.
Be extremely wary of invasive or aggressively spreading plants. Species like mint, bamboo, some types of ivy, and creeping Jenny can quickly overrun a confined box, choking out other plants. Their roots or runners can also escape through drainage holes, potentially causing issues. Always plant these in their own isolated, sealed containers if you must grow them.
Finally, reconsider plants with high and specific water, humidity, or temperature needs. Some delicate ferns, tropical plants, or moisture-loving species may struggle with the faster-draining soil and variable microclimates (wind, heat reflection) of an exposed urban setting. They often require more meticulous care than the average city gardener can consistently provide.
By steering clear of these unsuitable plants, you can focus on selections that will truly flourish in your urban oasis, ensuring a lush and rewarding container garden.