The Monkey Puzzle tree, known scientifically as Araucaria araucana, is native to the temperate rainforests of south-central Chile and adjacent parts of Argentina. It thrives in the Andean mountains at elevations between 1,000 and 1,500 meters, where it endures cold winters with significant snowfall and wet summers. This tree prefers volcanic soils, which contributes to its limited natural distribution, primarily in Chile’s Araucanía and Los Ríos regions, and slightly into Argentina’s Neuquén province.
The Monkey Puzzle tree has deep roots in the culture of the indigenous Mapuche people of Chile, who call it “pehuén.” For them, it’s not just a tree but a symbol of life, as its seeds have been a staple food source for centuries. These seeds, known as piñones, were crucial for survival, especially during harsh winters. The tree also features in Mapuche mythology, where it’s considered sacred, symbolizing strength and endurance.
The tree came to the attention of the Western world in the 19th century when it was introduced to Europe by plant collectors. Its peculiar appearance led to its English name “Monkey Puzzle,” reportedly coined because the tree’s dense, spiny branches were thought to be too difficult for a monkey to navigate. This catchy name helped popularize it in gardens outside its native range.
Due to habitat loss, logging, and the expansion of agriculture, the Monkey Puzzle tree has faced threats to its survival. It has been protected by law in Chile since the 1970s, and it’s listed as an endangered species by the IUCN. Conservation efforts include reforestation projects and protected areas to ensure its survival.
It is the hardiest species in the conifer genus Araucaria. Because of the prevalence of similar species in ancient prehistory, it is sometimes called an animate fossil. It is also the official tree of Chile and of the neighboring Argentine province of Neuquén.
Characteristics
- Appearance: The Monkey Puzzle tree is instantly recognizable for its unique, symmetrical shape and spiny foliage. It grows slowly to heights of 30 to 40 meters, with a diameter that can reach up to 2 meters. The trunk is straight, and the branches are arranged in a spiral, giving the tree a layered, almost architectural look. Each branch is adorned with sharp, stiff leaves that point outwards, creating an impenetrable barrier.
- Leaves and Bark: The leaves are thick, triangular, and remain on the tree for several years, turning brown but not falling off until new growth pushes them out. This gives the tree a persistent, evergreen appearance. The bark is rough and gray, providing additional protection against harsh weather.
- Reproduction: The tree is dioecious, meaning there are separate male and female trees. Male trees produce pollen cones, while female trees bear large, seed-bearing cones. The seeds, or piñones, are large, about 4-5 cm long, and are an important food source. They are released from the cones in autumn.
- Adaptations: Its spiny foliage is an adaptation to deter herbivores, while its ability to withstand cold, snow, and fire showcases its resilience in its native highland environment. The tree’s growth pattern also allows it to develop a strong, wind-resistant structure.
- Cultivation: Outside its native range, it’s cultivated for ornamental purposes, though it requires a similar climate to thrive. In gardens, it’s a conversation piece due to its bizarre yet beautiful form, requiring little maintenance once established but needing space due to its potential size.
USDA Zones
The Monkey Puzzle tree is best suited to USDA Hardiness Zones 7 through 10, reflecting its native habitat’s climate range from temperate to subtropical with cool winters. In these zones, it can tolerate occasional frosts but thrives in areas with mild, wet winters and cool, moist summers. In colder parts of Zone 7, it might require some winter protection, while in warmer zones, ensuring it doesn’t get too hot or dry in summer is crucial.
Cultivation
- Site Selection: When planting a Monkey Puzzle tree, choose a location with full sun to partial shade. It prefers well-drained, acidic to neutral soils, with a preference for volcanic or sandy loam. Avoid waterlogged sites as this can lead to root rot. The tree’s eventual size and slow growth mean you’ll need to plan for its space requirements from the beginning.
- Soil and Planting: Ensure the soil is well-draining; if your garden soil is heavy, amend it with sand or compost. Planting should be done in spring or early autumn to help the tree establish before extreme weather. Given its deep root system, it’s best to plant it where it won’t need to be moved.
- Watering: Young trees need regular watering to establish, but once mature, Monkey Puzzle trees are quite drought-tolerant. However, consistent moisture, especially during dry spells, will promote better growth. Overwatering, particularly in poorly drained soils, can be detrimental.
- Maintenance: This tree is low-maintenance once established. Pruning is generally unnecessary due to its natural shape, but removing dead or damaged branches can be done. Be cautious of the sharp leaves when pruning.
- Propagation: Propagation is generally from seed, which requires patience as germination can be slow and germination rates low. Seeds should be stratified (kept in a cold, moist environment) for several months before planting. Grafting is another method, though less common for home gardeners.
- Pests and Diseases: In its native habitat, it’s relatively pest-free, but elsewhere, it can be susceptible to aphids, scale insects, and fungal issues if conditions are too wet or the air circulation is poor.
Landscape Uses
- Specimen Plant: Due to its unique, sculptural form, the Monkey Puzzle tree makes an excellent focal point in large gardens or parks. Its slow growth means it’s a long-term investment that matures into a dramatic landscape feature.
- Botanical Gardens and Arboretums: These trees are often showcased in botanical collections for their rarity and visual interest, educating visitors about exotic flora and conservation.
- Privacy Screen: While it grows slowly, its dense, spiny foliage can eventually provide a formidable natural barrier, though this use requires long-term planning due to its growth rate.
- Historical or Cultural Landscapes: In areas where its cultural significance is recognized, especially in relation to indigenous peoples like the Mapuche, planting a Monkey Puzzle tree can serve as a cultural landmark or educational tool.
- Conservation and Restoration: In its native regions or in areas with suitable climates, planting Monkey Puzzle trees can contribute to conservation efforts, helping to restore native habitats or support local biodiversity.
- Urban Landscapes: In cities within its hardiness zones, it can be used for its aesthetic value in public parks or larger residential areas where its slow growth and large eventual size are not prohibitive factors.