The Bird of Paradise plant (Strelitzia) is a popular specimen instantly recognizable by its tropical, fan-like foliage. Its common name comes from the strikingly colorful flowers that resemble a crested bird in flight. Determining the maximum size a Bird of Paradise will achieve depends highly on genetics and the environment. The two most commonly grown species represent vastly different scales, making it crucial to know which variety you possess.
Size Differences Between Common Species
The term “Bird of Paradise” typically refers to one of two species, each possessing a different genetic size potential. The standard or Orange Bird of Paradise, Strelitzia reginae, is the more manageable species, especially for indoor cultivation. When mature, this species generally reaches a height of four to six feet, with a spread of two to five feet, forming a dense, clumping perennial.
In contrast, the Giant or White Bird of Paradise, Strelitzia nicolai, requires significant space. Outdoors in a tropical climate, this species can reach heights of 20 to 30 feet, developing a broad, woody base and a spread of up to 20 feet. The leaves alone can grow to six feet long and resemble banana foliage. Even when grown in a container indoors, S. nicolai will attempt to achieve a height between eight and twelve feet, often reaching the ceiling of a typical home.
This size disparity is fundamental: Strelitzia reginae is contained enough to be a robust houseplant, while Strelitzia nicolai is fundamentally a tree-like landscape plant. The massive root system required to support the Giant Bird of Paradise means it can quickly outgrow all but the largest indoor spaces. Understanding the genetic size limit provides the baseline for what environmental factors will then regulate growth.
Environmental Factors Limiting Growth
The size a Bird of Paradise ultimately achieves is primarily governed by the constraints of its growing environment, regardless of its genetic ceiling. Plants grown outdoors in warm, tropical zones with unlimited root space and consistent warmth can reach their maximum potential height and spread. Moving the plant indoors, however, immediately imposes several restrictions that stunt its growth.
One of the most significant governors of size is the container itself, as root mass directly dictates above-ground growth. The Bird of Paradise develops thick, tuberous roots that quickly fill a pot, creating a root-bound condition. A smaller pot restricts the expansion of these roots, which slows the production of new foliage and limits the plant’s overall scale.
The availability of light plays a role in determining the plant’s vigor and size. Insufficient light levels, common in many indoor environments, cause the plant to grow more slowly and produce smaller, stretched-out leaves. The volume and consistency of water and nutrient delivery also impact the plant’s ability to sustain large-scale growth. Inconsistent watering or poor soil quality prevents the plant from accessing the resources needed to build large leaves.
Practical Strategies for Size Management
Gardeners who wish to keep their Bird of Paradise at a manageable size must actively intervene using several maintenance techniques. The most effective passive method for size containment is strategic repotting, or the lack of it. Allowing the plant to become slightly root-bound restricts root growth, which naturally limits the size of the overall foliage clump.
When repotting becomes necessary, move the plant to a container only two inches larger in diameter than the previous one. This gradual increase helps slow the growth rate while providing enough fresh soil to maintain health. Because the plant has long, tuberous roots, selecting a pot with adequate depth is more important than choosing one that is excessively wide.
Pruning is another method of size management, though it is limited to controlling the plant’s visual bulk and spread. Bird of Paradise plants do not respond well to having their height reduced by cutting the main stems. Management involves removing older, damaged, or yellowing leaves and spent flower stalks at the base of the plant near the soil line. This reduces the overall spread and encourages air circulation without altering the plant’s fundamental height. For large, dense clumps, division is the only way to significantly reduce the plant’s footprint, which involves separating the root ball into smaller, independent individuals.