The Madagascar Palm (Pachypodium lamerei) is a plant that challenges expectations about size. Despite its common name, this species is not a true palm tree; it is a stem succulent, more closely related to plants like the Desert Rose. The plant’s overall size potential varies drastically depending on whether it is grown in its native, unrestricted habitat or cultivated as an indoor houseplant.
The Madagascar Palm’s Maximum Size
Under ideal, unrestricted conditions in its native arid regions of Southwest Madagascar, the Madagascar Palm is a formidable tree. It possesses the genetic potential to reach impressive heights, often topping out between 20 and 30 feet (about 6 to 9 meters).
The most defining feature of a mature outdoor specimen is its thick, bottle-shaped trunk, known scientifically as a caudex. This silvery-gray caudex can swell to a diameter of up to one foot, serving as the plant’s water storage reservoir. The trunk is intensely covered with sharp, organized spines and is typically solitary, rarely branching unless damaged or mature enough for flowering.
Environmental and Container Limitations on Size
The massive size achieved in the wild is dramatically curtailed when the Madagascar Palm is grown in a home environment. The primary factor limiting its vertical growth is the physical restriction of its root system within a container. When the plant becomes root-bound, its growth naturally slows down significantly, effectively dwarfing the plant to a manageable indoor size of about 4 to 8 feet.
Gardeners can actively manage the plant’s height by controlling the frequency of repotting and the size of the new container. Repotting into a container that is only slightly larger than the previous one every few years helps maintain a balance between healthy root growth and restricted overall size.
This species requires extensive light, and the lower light levels common indoors can cause a specific structural change known as etiolation. When a Madagascar Palm does not receive the required four to six hours of daily direct sunlight, its trunk will thin out as it stretches upward to search for illumination.
Managing Height
Growers can use pruning to limit the height of an overly tall plant. Pruning may also encourage the trunk to branch, altering its naturally solitary growth habit.
Growth Rate and Longevity
The Madagascar Palm’s growth rate is moderate. In ideal outdoor conditions, the plant may add between 4 and 12 inches of height annually, but reaching its full 20-foot potential requires many decades of sustained growth.
When grown as a houseplant, it may take 15 years or more for the plant to reach a height of just five to six feet. The relatively slow growth rate contributes to the plant’s long lifespan, as it is known to thrive for decades in cultivation. This means that an indoor grower will have a manageable, decorative specimen for a long period.