Ginkgo tree

Family

Ginkgoaceae

Habit

Tree

Height

35 m

Spread

10 m

Growth

very slow

Lifespan

1000 years

First yield

after 35 years

Yield per plant

up to 50 kg a year

Yield in cultivation

up to 7 t/ha

Energy yield

1300 kcal per m² a year

Hardiness

zone 4–10

Shade tolerance

light shade

Soil

Sand, Silt, Loam

Soil moisture

very dry – very moist

pH

5.5 – 9

Synonyms

Ginkgo, Gingko

Times apply to the northern hemisphere in a temperate climate and shift with altitude and cultivar.

Edible: The seed can be consumed either raw or cooked in small amounts, offering a soft, oily texture and a sweet taste similar to large pine nuts. When cooked, it has a flavor resembling a mix of potato and sweet chestnut. It is versatile in various dishes like soups and porridge but should be cooked beforehand to eliminate its slightly sharp taste. While some sources suggest raw consumption is possible, others caution against excessive intake due to potential toxicity. Rich in niacin, the seed provides a good source of starch and protein with low fat content, primarily unsaturated or monounsaturated. Additionally, the seed is used for extracting cooking oil.

Medicinal: Ginkgo has a rich history in traditional Chinese medicine, with its seeds being the primary focus. The plant's leaves contain active compounds that can enhance blood flow, boost cognitive function, and enhance memory. Additionally, they can improve peripheral circulation and potentially alleviate conditions like tinnitus. Ginkgolides, unique components in the leaves, have anti-allergic properties that may benefit individuals with asthma. The ginkgo fruit possesses antibacterial, antifungal, and calming qualities. Traditionally, the boiled seeds have been utilized to address asthma, coughs, and urinary issues, although caution is necessary due to reported cases of toxicity.

Other uses: The leaves are economically the most important part today: their extract underpins a worldwide pharmaceutical and supplement industry. Ginkgo is grown in plantations for this purpose — the largest lies at Sumter, South Carolina, where millions of closely spaced trees are cut back to ground level every five years and harvested mechanically; China has some 5,000 hectares, mainly in Jiangsu and Shandong. Harvesting begins in mid-July while the leaves are still green, and they must be dried within twelve hours. The wood is light, soft and splits well, and is used in East Asia for shrines, temple buildings and furniture. In the garden the narrow habit and light shade are valued, making the tree a living support for grape or kiwi.

Site: Ginkgo is undemanding but needs space and time — it reaches 25 to 40 metres and lives for centuries. It avoids very wet and very dry soils; otherwise it grows on acid and calcareous ground alike, takes frost to around minus 30 degrees, and shrugs off road salt, exhaust and compacted urban soil like almost no other tree. Sex is the decisive question: the fleshy seed coat of female trees smells strongly of butyric acid as it rots and makes paths, terraces and parking spaces unpleasant for weeks — so set female trees well away from seating, or deliberately choose a male clone if you do not want to harvest seed. Its narrow crown casts little shade, which makes it a usable living support for grape or kiwi. It poses no risk to fruit plantings, sharing no diseases with them. Care: Pruning is unnecessary but tolerated without complaint; in China cropping trees are kept to about five metres by regular cutting back. Fertilise sparingly, shelter young trees through their first winters, and after that the tree is practically indestructible — no significant pests or diseases are known. The foliage falls late and drops completely within a few days, which makes raking simple. Seeds ripen in October and November; wear gloves when removing the flesh, as the ginkgolic acids it contains irritate the skin. Seedlings need two to three decades to bear, and until then you do not know whether you have raised a male; grafted female cultivars fruit after three to five years, though markedly biennially.

Sowing is the usual route. The soft flesh must be removed completely before stratification — best done with gloves, as it irritates the skin. The cleaned seeds are stratified cool and moist over winter and sown in spring; germination is reliable. The drawback lies in the outcome: ginkgo is dioecious, and whether a seedling turns out male or female only becomes apparent after many years. Literature puts the time to first fruiting of seed-raised trees at twenty to thirty-five years, in practice usually considerably less. Anyone aiming for a harvest therefore grafts onto seedling rootstocks: grafted female cultivars bear after three to five years. Propagation from softwood cuttings in a warm greenhouse is possible but less common.

Ginkgo is of little value to wildlife, and there is no sugar-coating it: a relict more than 200 million years old with no relatives in the central European flora, wind-pollinated, offering neither nectar nor usable pollen, and no native caterpillar or wild bee has adapted to it. Its proverbial freedom from pests is precisely the flip side of that isolation. What it can contribute is structure: as a large, very long-lived tree it provides perching and nesting opportunities for decades, later cavities and deadwood, and it persists where urban climate, road salt and compacted soil defeat native species. Anyone whose main aim is to support insects will achieve many times as much with field maple, hornbeam or large-leaved lime.

Special features: The only surviving species of Ginkgo that grew on Earth 200 million years ago and survived the Hiroshima atomic bomb at a distance of only 800m (all life within a 2km radius was destroyed); the variety "Dafushon" produces 5-10kg at 15 years; 50-100kg at 50 years; requires very little shade + trellis for vines, kiwi and others; very rarely also monoecious,

East Asia: south-western China. Natural wild stands are documented only from a small area in south-western China — the southern slopes of the Jinfo Shan near Chongqing, where genetic diversity is highest, and a few small populations in neighbouring Guizhou. The original range lay in mesophytic mixed forest along the Yangtze. The well-known population on Tianmu Shan in Zhejiang, by contrast, probably goes back to plantings by Buddhist monks. From China the ginkgo reached Japan by way of Korea and Europe in 1730; today it is planted worldwide in temperate regions as a park, street and temple tree, without naturalising anywhere.

In the few stands regarded as natural, ginkgo grows in species-rich deciduous mixed forest in the hill country of south-western China, mostly on steep rocky slopes and in ravines between 300 and 1,100 metres, alongside oak, maple, hickory and magnolia. It tolerates acid and alkaline soils alike and grows better on the latter, but avoids both permanently wet and markedly dry substrates. As the relict of a plant group widespread some 200 million years ago it no longer has a coherent natural ecosystem; its effective habitat today is the planted park, temple and street site.