Palo Santo, or “Holy Wood,” is the common name for the tree species Bursera graveolens, native to the dry tropical forests of Central and South America. This deciduous tree has a long history of use in traditional practices, where its wood is burned as incense for its distinctive, sweet, and slightly citrus fragrance. The increasing global interest in this aromatic wood has spurred a desire for domestic cultivation, offering an alternative to purchasing wild-harvested material. Successfully growing this unique tree requires a deep understanding of its specific environmental needs, propagation challenges, and the decades-long process required for its wood to develop the prized aromatic resin.
Ethical and Legal Landscape of Palo Santo
Cultivating your own Palo Santo tree addresses concerns surrounding the sourcing of commercially available wood. The species Bursera graveolens is often mistakenly thought to be endangered due to confusion with Bulnesia sarmientoi, which shares a similar common name. Bursera graveolens is currently classified as a species of Least Concern by the International Union for Conservation of Nature.
Despite the “Least Concern” status, rising global demand has led to unsustainable practices, including the illegal cutting of living trees that lack mature aromatic oil. Ethical sourcing dictates that only wood from trees that have died naturally and aged on the forest floor should be collected. Growing your own plant ensures you are not contributing to the overharvesting or illegal logging of wild populations.
For those sourcing seeds or cuttings, be aware that the international trade of wood products is regulated. In the United States, importing wood, even in small quantities, may require adherence to the Lacey Act, which mandates declaring the species and country of origin. Many South American governments strictly prohibit the cutting of live Palo Santo trees, regulating the trade to only allow collection of naturally fallen wood.
Essential Environmental Requirements
The native habitat of Bursera graveolens is the seasonally dry tropical forest, requiring substantial heat and making the species extremely sensitive to cold temperatures and frost. Successful outdoor cultivation is generally limited to USDA Hardiness Zones 12a through 13b, with a preferred temperature range between 15 and 30°C.
Outside of these tropical and subtropical zones, a greenhouse or indoor environment is necessary to prevent cold damage. The tree requires full, unfiltered sunlight for optimal growth. As a deciduous species, it sheds its leaves during the dry season, adapting to periods of low water availability.
Propagation and Initial Care
Starting a Palo Santo tree can be accomplished through either seed germination or vegetative cuttings, both presenting challenges. Growing from seed is common, but the hard outer coat prevents water absorption, leading to poor germination without pretreatment. Seeds require scarification, achieved mechanically by lightly sanding the coat or by soaking them in hot water (approximately 70°C) for up to 24 hours.
Once pretreated, seeds should be sown in a well-draining, sandy medium and kept consistently warm. Vegetative propagation via cuttings is difficult with Bursera species, but higher rooting percentages are possible using semi-lignified material from younger stockplants. Cuttings benefit from rooting hormone application, such as Indol-butyric acid, and must be maintained in a humid environment away from direct sun until roots develop.
Young seedlings and newly rooted cuttings need careful attention to establish a robust root system. They must be protected from extreme weather fluctuations and transplanted incrementally to prevent root-bound conditions. Once established, the young tree is relatively fast-growing, quickly developing the characteristic irregular grooves in its bark.
Long-Term Cultivation and Maturation
Long-term care centers on replicating the tree’s native, arid environment. The tree thrives in poor, rocky, and exceptionally well-draining soil, often a combination of sand and clay. Overly rich or heavy soil retains too much moisture and quickly leads to root rot.
Mature trees are highly drought-tolerant and should be watered infrequently, allowing the soil to dry out completely between deep waterings. Pruning is minimal, focused on removing dead or crossing branches to maintain health and shape. The primary challenge of cultivation lies in the decades-long wait for the wood to achieve its aromatic properties.
The distinct fragrance is not present in wood from a living tree, regardless of its age. The aromatic resins and oils, rich in terpenes like limonene, develop only after the tree has naturally died. This decomposition and curing process must take place for an extended period, typically between four and ten years, for the fragrant heartwood to fully mature. Even in cultivation, obtaining the prized aromatic wood requires waiting for the tree to complete its natural lifespan and then allowing the fallen wood to age.