Ginkgo

Ginkgo biloba is believed to be native to a small area of eastern China, though no definitively wild populations have been documented with certainty, as the species has been cultivated for millennia. It may have been preserved from extinction entirely through human cultivation in temple and palace gardens.

• Possible native range restricted to the Tianmu Mountains (Tianmushan) in Zhejiang Province, eastern China, where a semi-wild population of approximately 250 trees persists in a forest reserve
• However, the Tianmu population may also represent feral specimens descended from cultivated trees rather than truly wild stock
• Cultivated in China for at least 1,500–2,000 years, with the earliest documented plantings at Buddhist and Confucian temples
• Introduced to Japan alongside Buddhism during the Tang Dynasty (618–907 CE), where it became a temple garden staple
• Brought to Europe by the German botanist Engelbert Kaempfer in the early 1690s, reaching the Netherlands by 1730 and England by 1754
• Now planted across temperate cities worldwide as a street and park tree, naturalising in some urban settings
• Ginkgo fossils are known from every continent including Antarctica, demonstrating the genus once had a virtually global distribution during the Mesozoic

Trunk & Bark:
• Trunk straight, columnar, 20–35 m tall, up to 1–3 m in diameter at maturity
• Bark grey-brown, deeply furrowed and ridged with age, developing characteristic corky projections (burls) on older specimens
• Wood relatively soft and light for a gymnosperm, with negligible commercial timber value

Leaves:
• Leaves deciduous, alternate or clustered on short shoots (spur shoots), fan-shaped (flabellate), 5–10 cm across
• Venation dichotomous — each vein forks repeatedly into two equal branches, a primitive feature shared with ferns
• Blade typically bilobed with a central notch of variable depth, though unlobed forms occur
• Bright green in summer, turning brilliant golden-yellow in autumn — one of the most spectacular autumn displays of any tree
• Petiole slender, 5–8 cm long, allowing leaves to flutter in the slightest breeze

Reproductive Structures:
• Dioecious — separate male and female trees
• Male trees produce pendulous catkin-like microsporangiate cones 2–3 cm long, releasing wind-borne pollen in spring
• Female trees bear paired ovules on slender stalks at the leaf axils, each developing into a fleshy seed-like structure
• "Fruit" (technically a seed with a fleshy sarcotesta) drupe-like, 2–3 cm, yellowish-green ripening to amber, containing a hard-shelled nut
• Fleshy sarcotesta produces butyric acid, responsible for the notoriously vomit-like odour of fallen seeds
• Seeds 1.5–2 cm, edible when roasted, with a soft, almond-like kernel

Root System:
• Deep taproot in youth, developing extensive lateral roots with age
• Remarkably resistant to root rot and soil-borne pathogens

Ginkgo biloba exhibits extraordinary ecological resilience that has contributed to its survival across geological time.

Habitat:
• In cultivation, adapted to a remarkably wide range of temperate urban and landscape settings
• Requires well-drained soil and full sun to partial shade
• Tolerant of compacted urban soils, air pollution, road salt, and restricted root space
• Hardiness spans USDA Zones 3–9, tolerating winter temperatures below -30°C

Ecological Resilience:
• Ginkgo trees were among the few living organisms to survive the atomic bombing of Hiroshima in 1945 — six Ginkgo trees within 1–2 km of the blast epicenter resprouted from their charred stumps the following spring and remain alive today
• Extreme disease resistance — virtually no significant pathogens or insect pests affect mature Ginkgo trees
• Resistance attributed to high concentrations of unique flavonoid glycosides (ginkgolides) and other secondary metabolites in leaf tissue
• Exceptional longevity — individual specimens in Chinese and Japanese temple gardens exceed 1,000 years, with some documented at over 3,000 years

Adaptations:
• Dichotomous leaf venation represents an ancient condition retained from Mesozoic ancestors
• Fleshy sarcotestra attracts seed-dispersing animals, though in modern times the malodorous fallen seeds are considered a nuisance
• Capable of producing aerial roots (chi-chi) from the lower trunk in response to stress — a rare feature in gymnosperms

Ginkgo seeds and leaves contain compounds that can cause adverse effects.

• Fresh Ginkgo seeds contain ginkgotoxin (4'-O-methylpyridoxine), which can cause seizures, loss of consciousness, and in rare cases death if consumed in large quantities — children are particularly susceptible
• The fleshy sarcotestra of the seeds contains urushiol-like compounds that can cause contact dermatitis similar to poison ivy in sensitive individuals
• Roasting the seeds destroys most of the ginkgotoxin and makes them safe for consumption in moderate quantities
• Ginkgo leaf extract supplements may interact with anticoagulant medications (warfarin, aspirin), increasing bleeding risk
• May interact with anticonvulsant medications and reduce their effectiveness
• Not recommended for individuals with bleeding disorders or before surgical procedures
• Pregnant and breastfeeding women should avoid Ginkgo supplements

Ginkgo biloba is widely planted as an ornamental and street tree, and is cultivated commercially for its medicinal leaf extract.

Site Selection:
• Adaptable to virtually any well-drained soil in full sun to partial shade
• Tolerates urban conditions including pollution, compacted soil, and limited root space
• Choose male cultivars (e.g., Autumn Gold, Princeton Sentry, Lakeview) for street planting to avoid the malodorous seeds produced by female trees
• Hardy to USDA Zones 3–9

Soil:
• Adaptable to a wide range of soils from sandy loam to heavy clay, provided drainage is adequate
• Prefers slightly acidic to neutral pH (6.0–7.0) but tolerates moderately alkaline conditions
• Deep, fertile, moist but well-drained soils produce the most vigorous growth

Planting:
• Plant container-grown or balled-and-burlapped specimens in spring or autumn
• Space large-growing varieties 9–12 m apart to accommodate mature crown spread
• Young trees benefit from staking for the first 1–2 years until established

Maintenance:
• Minimal pruning required — trees develop a naturally symmetrical crown with age
• Water regularly during the first 2–3 growing seasons until deep root establishment
• Relatively pest-free and disease-resistant — chemical treatments rarely needed
• Autumn leaf drop occurs within a brief 1–2 week period, creating a spectacular but brief golden carpet

Ginkgo biloba is one of the most commercially important medicinal plants in the world, with a global market for its leaf extract exceeding $1 billion annually.

Medicinal:
• Ginkgo leaf extract (standardised to 24% flavonoid glycosides and 6% terpene lactones) is among the most widely used herbal supplements globally
• Used primarily for cognitive enhancement, memory support, and peripheral circulation improvement in elderly populations
• Contains unique ginkgolides (A, B, C, J) and bilobalide — compounds found nowhere else in the plant kingdom
• Research on clinical efficacy remains mixed, with some studies showing modest cognitive benefits and others finding no significant effect

Culinary:
• Roasted Ginkgo nuts (Bai Guo) are a traditional ingredient in Chinese, Japanese, and Korean cuisine
• Used in congee, stir-fries, soups, and desserts — particularly in Chinese banquet cooking and Japanese chawanmushi
• Nuts have a soft, slightly starchy texture with a mild, sweet flavour reminiscent of chestnut

Cultural:
• Revered in East Asian Buddhist tradition — planted at temples for millennia as a symbol of longevity, resilience, and enlightenment
• The Ginkgo leaf has been adopted as the symbol of Tokyo, Japan, and features on the city's official seal
• Widely used in art, poetry, and heraldry across East Asia