Adansonia grandidieri aka Grandidier's Baobab
Taxonomy ID: 682
Adansonia grandidieri, commonly known as Grandidier's Baobab or the Giant Baobab, is the largest and most iconic of Madagascar's six endemic baobab species. Named after the French naturalist and explorer Alfred Grandidier who extensively studied Madagascar's flora and fauna, this magnificent deciduous tree is renowned for its distinctive silhouette featuring a massive cylindrical trunk topped with a flat crown of horizontal branches.
The tree's most striking feature is its enormous trunk, which can reach up to 3-5 meters in diameter and serves as a water reservoir during the prolonged dry seasons of its native habitat. The trunk is covered with smooth, reddish-grey bark and can store thousands of liters of water. Rising to heights of 25-30 meters, though stunted specimens in the southern part of its range may only reach 5 meters, these trees dominate the landscape of southwestern Madagascar.
The foliage of Adansonia grandidieri is distinctive among baobabs. The palmately compound leaves feature 9-11 leaflets with a unique bluish-green coloration, densely covered in star-shaped hairs—a characteristic that distinguishes this species from all other baobabs. Leaves appear at the start of the rainy season (October to May) and are shed during the dry season as a water conservation adaptation.
Flowering occurs during the dry season between May and August, before the leaves emerge. The large, spectacular white flowers open at dusk and emit a fragrance described as resembling sour watermelon. Each flower contains hundreds of thin white filaments at its center and produces abundant nectar to attract its nocturnal pollinators—primarily fruit bats, fork-marked lemurs, and hawk moths. The flowers release all their pollen during the first night of opening.
The fruits are large, oblong to ovoid structures with fragile walls covered in dense reddish-brown hairs, distinguishing them from other Adansonia species. They contain numerous kidney-shaped seeds embedded in an edible, vitamin C-rich pulp that ripens from green to brown by October. The seeds contain 36-39% high-quality cooking oil.
Endemic to the dry deciduous forests of southwestern Madagascar in the Menabe region, Adansonia grandidieri is now primarily found near waterholes and rivers, often in degraded agricultural land. The famous Avenue of the Baobabs near Morondava, featuring a spectacular row of these giants, has become one of Madagascar's most iconic natural landmarks. Known locally as 'renala' or 'reniala' meaning 'mother of the forest,' these trees hold deep cultural and religious significance for the Malagasy people.
Despite their longevity—some specimens living over 800 years—Adansonia grandidieri is classified as Endangered by the IUCN Red List. The species faces severe threats from habitat destruction due to agricultural expansion, slash-and-burn farming practices, and poor natural regeneration. Conservation efforts, including protected status for the Avenue of the Baobabs since 2007, aim to preserve this magnificent species for future generations.
Common names
Grandidier's Baobab, Giant Baobab, Renala, Reniala, Mother Of The ForestMore information about Grandidier's Baobab
How big does Adansonia grandidieri grow?
Adansonia grandidieri is the largest of Madagascar's baobabs, typically reaching 25-30 meters (82-98 feet) in height, though stunted specimens in the southern range may only reach 5 meters. The massive cylindrical trunk can grow to 3-5 meters in diameter, storing thousands of liters of water. Despite its eventual size, early growth is remarkably fast for its dry habitat—trees can reach 2 meters within 2 years from seed and 12-15 meters with a 60cm trunk diameter within 12 years. The crown is characteristically flat-topped with horizontal main branches.
Where is Adansonia grandidieri native to?
Adansonia grandidieri is endemic to southwestern Madagascar, found nowhere else in the world. Its range extends from north of Morondava to north of Morombe in the Menabe region. The species inhabits dry deciduous forests at low elevations, typically growing near waterholes and rivers. The famous Avenue of the Baobabs near Morondava features a spectacular row of these giants and has become one of Madagascar's most iconic landmarks. Known locally as 'renala' meaning 'mother of the forest,' these trees hold deep cultural and religious significance for the Malagasy people.
What soil does Adansonia grandidieri need?
Adansonia grandidieri requires well-draining soil, as it is highly susceptible to root rot in waterlogged conditions. A sandy or loamy soil mix is ideal, with slightly acidic to neutral pH. The species naturally grows in dry deciduous forests on well-drained soils near waterholes and rivers. For container cultivation, use a fast-draining succulent or cactus mix. Good drainage is essential—the tree stores water in its massive trunk rather than relying on moist soil.
What temperatures can Adansonia grandidieri tolerate?
Adansonia grandidieri requires warm temperatures and is strictly frost-intolerant. Minimum temperatures should not drop below 13-15°C (55-59°F). The species thrives in USDA hardiness zones 10a to 11b, tolerating temperatures from about 30°F (-1°C) to 50°F (10°C) at the absolute minimum. It prefers hot, dry summers and mild winters typical of tropical and subtropical climates. In colder regions, young plants can be grown in containers and moved indoors or to a greenhouse during winter.
What humidity does Adansonia grandidieri prefer?
Adansonia grandidieri is adapted to dry conditions and does not require high humidity. Native to the dry deciduous forests of southwestern Madagascar, it naturally experiences low humidity during the dry season when it sheds its leaves. The species stores water in its massive trunk rather than relying on atmospheric moisture. In cultivation, normal indoor or outdoor humidity is acceptable, and the tree actually performs better in drier conditions than in high humidity, which can promote fungal issues.
How should I fertilize Adansonia grandidieri?
Adansonia grandidieri does not require heavy fertilization. Apply a balanced, slow-release fertilizer once or twice a year during the active growing season (spring and summer). Over-fertilizing is unnecessary and can be counterproductive for this species adapted to nutrient-poor soils. When using liquid fertilizer, dilute to half strength. Avoid fertilizing during the dormant winter period when the tree has shed its leaves and is not actively growing.
How does Adansonia grandidieri care change by season?
Adansonia grandidieri follows a distinct seasonal cycle tied to Madagascar's wet and dry seasons. From October to May (the wet season), the tree is in leaf and actively growing—this is when to provide water and fertilizer. During the dry season (May to August), the tree flowers before shedding its leaves. In autumn and winter, reduce watering dramatically as the tree enters dormancy; it requires no water during this period and is highly susceptible to root rot if kept too moist. In colder climates, protect from frost by moving container plants indoors.
When and how does Adansonia grandidieri flower?
Adansonia grandidieri produces spectacular flowers during the dry season from May to August, before the leaves appear. The large white flowers have five petals arranged in a cup formation with hundreds of thin white filaments clustered at the center. They open just before or soon after dusk, emitting a fragrance described as resembling sour watermelon. All pollen is released during the first night of opening. The flowers produce abundant nectar to attract nocturnal pollinators including fruit bats, fork-marked lemurs, and hawk moths. After pollination, large hairy fruits develop and ripen to brown by October.
Can Adansonia grandidieri be grown outdoors?
Adansonia grandidieri can only be grown outdoors in tropical and subtropical regions with no frost—USDA zones 10a through 11b. It requires hot, dry summers, mild winters, and excellent drainage. In suitable climates like parts of Florida, southern California, or Hawaii, it can be planted directly in the ground. Despite its adaptation to dry conditions, it will thrive in rainier climates provided the soil is well-drained and temperatures stay above 13°C. In most temperate regions, it must be grown in containers and moved indoors during winter.
How do I propagate Adansonia grandidieri?
Adansonia grandidieri is most commonly propagated from seed. Soak seeds in hot water for 24 hours to soften the hard outer coat (change water every few hours). Plant seeds about 2.5cm deep in moist, well-draining compost at 23-27°C. Germination typically occurs within 3-7 weeks, though success rates can be variable due to the hard seed coat. Hot water treatment significantly improves germinability. The species can also be propagated from cuttings. Young seedlings grow quickly—reaching 2 meters within 2 years—but require protection from cold and overwatering.
How is Adansonia grandidieri pollinated?
Adansonia grandidieri is pollinated by nocturnal animals, primarily fruit bats, which are attracted by the flowers' abundant nectar and distinctive scent. Fork-marked lemurs (endemic to Madagascar) also serve as important pollinators, as do hawk moths and other nocturnal insects. The flowers open at dusk and release all their pollen during the first night, maximizing the chance of cross-pollination by these nocturnal visitors. This specialized pollination system is typical of baobabs and represents an important ecological relationship.
Is Adansonia grandidieri edible?
Yes, Adansonia grandidieri has edible parts traditionally consumed in Madagascar. The fruit pulp is rich in vitamin C, calcium, and phosphorus, and is eaten fresh. The kidney-shaped seeds contain 36-39% high-quality cooking oil with a favorable fatty acid composition including palmitic acid (38%), oleic acid (23%), and linoleic acid (16%). This oil was historically exported to Europe. While primarily consumed locally, the fruits and seed oil represent valuable food resources for Malagasy communities.
What are the uses of Adansonia grandidieri?
Beyond food, Adansonia grandidieri has several traditional uses. The thick bark (up to 15cm wide) contains tough, long fibers used to make strong ropes, particularly valued for canoe ropes. Dried wood sheets serve as thatching material for traditional buildings. The spongy trunk wood is fed to cattle during drought periods when other fodder is scarce. More recently, the high-quality seed oil has gained commercial interest in the cosmetics industry as a humectant and conditioner. The trees also hold deep cultural and religious significance for the Malagasy people.
Does Adansonia grandidieri need pruning?
Minimal pruning is required for Adansonia grandidieri. The tree naturally develops its characteristic flat-topped crown with horizontal branches. Simply remove any dead, damaged, or diseased branches as needed, and cut away any suckers that emerge from the base of the trunk. Major structural pruning is generally unnecessary and not recommended for this slow-growing species that can live for centuries. Young container specimens being trained as bonsai may require more regular pruning to maintain desired shape.
When should I repot Adansonia grandidieri?
Young Adansonia grandidieri grown in containers should be repotted as they outgrow their pots, typically every 1-2 years during the active growing season (spring to early summer). Choose a pot only slightly larger than the current one and ensure it has excellent drainage. Use a well-draining succulent or sandy soil mix. Container-grown specimens can be maintained for many years before becoming too large for indoor spaces. When repotting, take care not to damage the developing caudex (swollen trunk base) as this is characteristic of the species.
Does Adansonia grandidieri have a scent?
The flowers of Adansonia grandidieri have a distinctive fragrance often described as resembling sour watermelon. This unusual scent, combined with abundant nectar production, attracts the tree's nocturnal pollinators—particularly fruit bats and hawk moths. The fragrance is released as flowers open at dusk and is most noticeable during the first night when all pollen is released. The leaves and other parts of the tree do not have a notable fragrance.
