The Ginkgo biloba, often called the maidenhair tree, is a unique species with a lineage stretching back over 200 million years, earning it the nickname “living fossil.” Originating in East Asia, this ancient tree is now widely cultivated globally for its distinct fan-shaped leaves and spectacular golden-yellow autumn color. Its remarkable tolerance for urban pollution, compacted soil, and disease has made it an exceptionally popular and resilient choice for streetscapes and city parks across North America and Europe.
Defining Invasiveness and the Ginkgo’s Status
The term “invasive species” is a specific ecological designation for a species that is non-native and whose introduction causes or is likely to cause economic or environmental harm. For a plant to be truly invasive, it must spread aggressively and outcompete native flora, displacing them from their ecological niches. The Ginkgo biloba tree is non-native, originating in China, but it is overwhelmingly not considered invasive in regions like North America. It lacks the rapid, self-sustaining spread and aggressive ecological displacement required for this classification. The species is frequently recommended for use in urban horticulture programs, indicating its non-invasive status.
Understanding Ginkgo Reproduction and Spread
The biological mechanisms of the ginkgo prevent it from spreading aggressively into natural areas. Ginkgo biloba is a dioecious species, meaning individual trees are either male or female, and both sexes must be present within wind-pollination distance for viable seed production to occur. Seedling trees require an extremely long period to reach sexual maturity, often taking 20 years or more before they begin to produce reproductive structures. This delayed maturity restricts the rate at which a population can reproduce and expand. Naturalized populations are exceptionally rare and typically only appear in highly disturbed urban environments, where they are considered “weakly naturalized” rather than ecologically invasive.
Practical Considerations for Planting
While the ginkgo is not an ecological threat, female trees present a significant nuisance issue. Female ginkgos produce a seed surrounded by a soft, fleshy outer layer, which is not a true fruit. When this seed drops in the autumn and the outer layer breaks down, it releases a strong, unpleasant odor due to the presence of butyric acid, often likened to rancid butter. To avoid this messy problem, landscape professionals recommend planting only male cultivars, which are clones propagated by grafting and are fruitless. The tree also develops a deep and wide-spreading root system, so its mature size must be considered during placement to ensure adequate distance from building foundations or pavement.