Overview
Ginkgo biloba is a botanical anomaly of the highest order — the sole surviving member of an entire division of plants, the Ginkgophyta, that thrived during the age of dinosaurs. Fossil records reveal that ginkgos essentially identical to today's trees existed more than 270 million years ago, predating the evolution of flowering plants by some 200 million years, the extinction of the dinosaurs by 205 million years, and the emergence of anatomically modern humans by about 270 million years. Nothing about the ginkgo's appearance or biology has changed appreciably in all that time, earning it the title of "living fossil" from Charles Darwin.
The tree's appearance is unlike any other. Its fan-shaped leaves, deeply notched into two lobes (giving the species its name: biloba means "two-lobed"), turn an extraordinary pure golden yellow in autumn before dropping almost simultaneously over a 24-hour period — a brief but spectacular display that draws crowds to ginkgo-lined avenues in Japan, Korea, China, and increasingly in European and North American cities. The trunk is straight, the crown conical in youth, broadening to irregular with age. Young bark is smooth and pale grey; old bark thickens into deep longitudinal furrows.
Ginkgo is classified as a gymnosperm, more closely related to conifers and cycads than to any flowering plant. It is dioecious — male and female reproductive structures occur on separate trees. Male trees produce pollen-bearing catkins; female trees bear ovules that, when pollinated, develop into fruit-like seeds with a soft, fleshy outer layer (the sarcotesta) surrounding a hard inner shell. The sarcotesta contains butyric acid, which gives ripe seeds a notoriously unpleasant smell often likened to vomit or rancid butter — a significant factor in the commercial preference for male trees in street planting.
Wild ginkgo trees survive in only two small populations in Zhejiang and Guizhou provinces in eastern China, and even these may represent trees that escaped from cultivation around monasteries rather than truly wild populations. The species was essentially saved from extinction by Buddhist monks who cultivated ginkgo in temple gardens throughout China, Korea, and Japan for over a millennium. From these temple gardens, the tree was introduced to Europe in 1730 and to North America shortly after, where it has proven remarkably adapted to urban conditions, withstanding pollution, compacted soils, and salt spray that defeat most other tree species.
Benefits of Ginkgo
Cognitive Health
Standardised ginkgo leaf extracts (particularly EGb761) are among the most studied botanical medicines in the world. Clinical evidence supports their use in improving blood flow to the brain, potentially enhancing memory, concentration, and processing speed in older adults with cognitive decline.
Circulatory Support
Ginkgo flavonoids and terpenoids improve peripheral blood circulation and reduce platelet aggregation. They have been clinically studied for peripheral artery disease, Raynaud's phenomenon, and tinnitus associated with reduced blood flow, with documented improvements in walking distance and symptom severity.
Antioxidant Protection
Ginkgo leaves contain a remarkable diversity of antioxidant compounds — flavonol glycosides (quercetin, kaempferol, isorhamnetin) and terpene lactones (ginkgolides, bilobalide) — that neutralise free radicals and protect cellular membranes from oxidative damage throughout the body.
Urban Resilience
Ginkgo is one of the most pollution-tolerant trees available for urban planting. It withstands vehicle exhaust, soil compaction, ozone, and road salt with exceptional resilience. Its relatively narrow juvenile canopy makes it ideal for street tree planting where space is limited.
Ornamental Value
Few trees match the ginkgo's autumn spectacle. The simultaneous golden leaf drop, occurring over just 1–2 days, creates a dramatic carpet effect beneath the tree. Cultivars such as 'Autumn Gold', 'Fastigiata', and 'Mariken' have been selected for garden use for their consistent coloration and ornamental form.
Growing Conditions
Care Guide
Ginkgo trees are planted from container-grown specimens or balled-and-burlapped nursery stock, ideally in spring or autumn. They establish slowly — do not be discouraged by minimal growth in the first 2–3 years, as the tree is developing its extensive root system during this establishment period. Choose a male cultivar (or a grafted male plant) for street and garden planting to avoid the malodorous fruit of female trees. Male cultivars can be identified reliably only by specialist growers; grafted cultivars such as 'Autumn Gold' and 'Princeton Sentry' are certified male.
Water young trees thoroughly once per week during the first two growing seasons, then reduce frequency as the tree establishes. Ginkgo is tolerant of urban air pollution, reflected heat from paving, drought, and moderate soil compaction — qualities that make it exceptional for street and plaza planting. It responds well to a mulch of organic material extending to 1 metre from the trunk, which improves soil structure in compacted urban soils and reduces moisture competition from lawn grass.
Ginkgo requires very little pruning once a satisfactory form is established. Remove crossing or rubbing branches in early spring before growth commences. The tree naturally develops a strong central leader in youth; this should not be disturbed. Very old ginkgos develop aerial roots and basal sprouts (called "chichi") — woody projections hanging from lower branches — that are normal features of aged specimens and should not be removed. Fertilise established trees lightly in early spring with a balanced granular fertiliser if growth appears sluggish.
Ginkgo has no significant pest or disease problems — a consequence of its chemical complexity and extraordinary evolutionary history. It appears to have outlasted all organisms that specifically preyed upon it. A few non-specialist pests such as scales and borers occasionally colonise stressed trees, but healthy, well-established ginkgos rarely experience any serious problems. This pest resistance, combined with its pollution tolerance and brilliant autumn colour, accounts for the tree's growing popularity as a street and park tree throughout the temperate world.
Interesting Facts
- Six ginkgo trees survived the atomic bombing of Hiroshima in 1945 at distances of 1–2 km from the hypocentre. While all other vegetation in the area was incinerated, the ginkgos re-sprouted the following spring and are still alive today, designated as "A-bombed trees" and revered as symbols of resilience.
- Ginkgo is classified as "Endangered" on the IUCN Red List in its wild form, yet it is one of the most widely planted trees in cities worldwide — a paradox of conservation and cultivation that makes it among the most abundant endangered species on the planet.
- The ginkgo reproduces using motile sperm — sperm cells that swim toward the egg using whiplike flagella — a reproductive strategy it shares with ferns and mosses but that no other tree species uses. This ancient trait was discovered in 1896 by Japanese botanist Sakugoro Hirase.
- Ginkgo seeds (known as bai guo in Chinese, meaning "white fruit") have been a prized ingredient in East Asian cuisine for over 1,500 years, used in congee, dessert soups, and tea ceremony sweets. The seeds must be cooked to neutralise a mild toxin present in the raw nut.
- A single ginkgo tree in Gu Guanyin Buddhist Temple in the Zhongnan Mountains of China is believed to be 1,400 years old. Every autumn, its simultaneous leaf drop creates a golden sea covering the courtyard floor, attracting tens of thousands of visitors.
Frequently Asked Questions
The evidence for ginkgo's cognitive effects is mixed but leans towards modest benefit for people with age-related cognitive decline or early dementia. Multiple clinical trials of standardised ginkgo extract (EGb761) have shown improvements in memory, attention, and activities of daily living in older adults. However, large trials in healthy adults have not shown significant benefits for preventing age-related memory decline. Always consult a healthcare professional before using ginkgo supplements, particularly if you take blood-thinning medications, as ginkgo can potentiate anticoagulant effects.
The fleshy outer layer (sarcotesta) of ginkgo seeds contains high concentrations of butyric acid — the same compound responsible for the smell of vomit and rancid butter — along with other short-chain fatty acids. This odour is thought to have attracted large frugivorous animals during the Mesozoic era that would have dispersed the seeds after eating the flesh. Today, with most such animals extinct, the smell serves little dispersal purpose, making female ginkgos unpopular in cities. Most street trees are now grafted male clones that never produce seeds.
Young ginkgo trees cannot be reliably sexed before they reach reproductive maturity at 20–30 years. Male trees produce small, catkin-like pollen structures in spring; female trees produce pairs of ovules on long stalks. Nursery-sold ginkgos are either grafted clones of known sex or seedlings of unknown sex. For guaranteed male trees (to avoid fruit production), purchase from a reputable nursery that sells named cultivars with certified sex, such as 'Autumn Gold', 'Princeton Sentry', or 'Magyar' (all male).
Ginkgo growth rates vary considerably with soil quality and climate. In optimal conditions, young trees in their first decade can add 30–60 cm of height per year. Growth slows significantly in later decades. In urban street situations with compacted soils, growth may be as little as 15–20 cm per year. The tree reaches its ultimate height of 20–35 metres over many centuries, with some very old specimens considerably exceeding this range. Despite its slow growth, ginkgo is considered worthwhile for street planting because of its exceptional longevity and hardiness.