<em>Ginkgo biloba</em>, maidenhair tree: planting, care and uses

Description and botany

A true living fossil, Ginkgo biloba, also called “maidenhair tree” or “silver apricot“, appeared on Earth during the Jurassic, about 190 million years ago. It is now the last surviving representative of its family, Ginkgoaceae, the oldest botanical family still present on Earth, which appeared nearly 270 million years ago.

Native to south-east China, in the Tianmushan mountains, it now survives almost only in cultivation. Its conservation status is listed as “endangered” and the Tianmushan nature reserve was created to continue protecting the last wild specimens and that particular biotope.

Cultivated in China for millennia and in Japan and Korea since the 12th century. The first Ginkgo biloba reached Europe only in 1730, in Utrecht. In France it was brought back by Auguste Broussonier in 1778 and planted in the Jardin des Plantes in Montpellier. A cutting from that specimen was taken and planted in 1795 at the Jardin des Plantes in Paris. Both are still alive and in good health today.

Slow-growing in its early years, Ginkgo biloba can become very large, over forty metres, and live for very long periods. Some planted in Asia are millennia-old. According to Francis Hallé, it could even be immortal since it is known to have no predator, no disease and no parasite. Only climatic hazards or the axe of the woodcutter can put an end to it. Even a nuclear explosion did not suffice… Indeed, Ginkgo biloba was the first tree to regrow in Hiroshima after the war.

→ To learn more about secret of its longevity, we recommend reading this article: “No planned obsolescence for Ginkgo biloba!“

Ginkgo biloba – lithograph by Philipp Franz von Siebold and Joseph Gerhard Zuccarini

Its deciduous foliage is palmate, bilobed (hence species name “biloba“) and petiolate, the leaves being grouped in threes or fours on short shoots. Leaves are more notched on female specimens (see below). Initially pale green, the foliage turns a particularly striking golden yellow in October. Bark is brown-grey, smooth when young then cracking and fissuring with age. On trunks of older subjects form tchitchis, growths resembling breasts.

It is a dioecious plant, that is, there are male and female trees. Male trees produce small aments that disperse pollen and female trees bear naked flowers without floral parts. These develop into ovules which, once on the ground and fertilised by pollen, emit an unpleasant smell of rancid butter (butyric acid). Prefer male trees for planting. In fact, all selected varieties are male to avoid this slight nuisance. Do not confuse the ovules, those small fleshy yellow-brown balls, with fruits or seeds. Indeed, ginkgos are classed among the Prespermaphyta; they therefore do not produce fruits or seeds, which means that the ovule, once fertilised, must germinate as quickly as possible, often at base of tree. The young plant thus formed will not be sexually mature until at least 15 years.

Ginkgo biloba prefers to grow in full sun. It is very hardy, very resilient and highly tolerant regarding soil. An ordinary, well-drained soil, even slightly calcareous, suits it, but it does not appreciate stagnant moisture. It withstands drought, wind and air pollution.

In youth, Ginkgo resembles a kind of large skeletal broom, eventually adopting, over the years, a broad, upright habit with very short shoots. Male specimens have a more erect habit while female specimens develop a more spreading habit and are a little less vigorous. There are columnar varieties (such as ‘Blagon’ for example) or weeping forms (variety ‘Pendula’).

Foliage of Ginkgo biloba through the seasons

Our favourite varieties

Ginkgo biloba - Maidenhair Tree

This is the type species. Splendid as a specimen in a sunny garden, it requires a substantial space because, besides its sometimes spectacular height of up to twenty metres, its width of about ten metres may rule it out for small gardens.

• Height at maturity 15 m

See the product sheet

Ginkgo biloba fastigiata Blagon

Ginkgo biloba 'Blagon' is much less space-consuming than the previous one. Its fastigiate habit gives it a maximum width of two metres, which allows it to be happily inserted into a modest-sized garden.

• Height at maturity 10 m

See the product sheet

Ginkgo biloba Mariken

Ginkgo biloba 'Mariken' grows slowly and reaches two metres only after many years. As splendid in autumn as the type species, its bilobed leaves are nonetheless smaller and slightly crinkled.

• Height at maturity 2,50 m

See the product sheet

Ginkgo biloba Troll

A true little botanical gem, Ginkgo biloba 'Troll' is perfect for container or bonsai culture as it does not exceed one metre in any direction. It will also make a sensation in a Japanese-style rockery.

• Height at maturity 1,10 m

See the product sheet

Planting a Ginkgo biloba

Exposure and soil

Ginkgo biloba is very easy to grow and appreciates sunny positions. Regarding soil, it is not fussy: ordinary soil, even poor, stony or calcareous, matters little. The only thing it dislikes in soil is stagnant water.

Planting period

Wait until spring, after frosts (March–April), to plant your Ginkgo biloba as a root ball or in a container. You can also, as with other conifers and evergreens, plant it in early autumn (October) to ensure good rooting before winter. Prefer young trees for reliable establishment.

How to plant a Ginkgo?

In open ground

• Immerse container in water for a few hours to re-moisten the root ball
• Remove tree from pot but do not destroy the root ball
• Dig a hole twice the width and twice the depth of the root ball
• Ginkgo has a tap root that will anchor the tree in the soil before growth of adventive roots. Therefore it is preferable to loosen the soil deeply at the bottom of the hole
• Once soil is loosened, add a few handfuls of well-rotted compost; you can add a little sand if your soil is compact
• Place root ball at bottom of hole and backfill with excavated soil
• Firm surface and apply ten litres of water to avoid possible air pockets
• Apply mulch (dead leaves, herbs, …) to help your tree through any summer drought and/or periods of frost in winter, at least during those first years

In a pot

• Immerse container in water for a few hours to re-moisten the root ball
• Remove tree from pot but do not destroy the root ball
• Choose a container with a volume twice that of the root ball. Make sure there are drainage holes!
• Use a mix of 1/3 potting compost – 1/3 ordinary soil – 1/3 sand to provide a rich but light, well-drained medium
• Place a drainage layer of small gravel at base of pot, then a layer of about one-third of pot height of your soil mix
• Place root ball in pot and backfill with your soil mix
• Firm surface and water well to avoid possible air pockets
• You can place a “mulch” around the trunk with pebbles or bark. please note : for a bonsai, technique remains identical but you will need to prune nearly half of the roots with a pair of cutters sterilised with alcohol. Cut should be fairly deep, at least 15–20 centimetres deep. In winter, shelter tree in a frost-free location. Soil mix can be 70% Akadama and 30% potting compost for better drainage.

Multiplication

By sowing fertilised ovules

You can simply collect gently young shoots that have germinated beneath an adult female tree or pick up a few ovules fallen to ground. Soak collected ovules in water at 70°C for five minutes to crack their outer covering. If not in a hurry, place ovules to be stratified in damp sand over winter (less effective in my experience). Sow immediately under cover in a bonsai potting compost or a light, well-draining soil (half potting compost – half sand). Keep your young plant for one year before transplanting into open ground.

Ginkgo biloba ovules

By propagation by cuttings

Take short lateral semi-ripe shoots, that is, a shoot of the year that has begun to become lignified at the base but remains soft at the tip. Remove leaves except two or three at the tip. Most leaves are always removed from a shoot or branch intended for cuttings; this reduces excessive evapotranspiration while keeping some for photosynthesis. Coat the tip with plant hormone for cuttings or dip it in a little water in which you have soaked some willow branches for one or two nights (a natural, free rooting plant hormone!) to help rooting. Insert the shoot into a mix of potting compost and sand. Wait a few months after rooting is clearly visible before placing the tree in open ground.

By air layering

Peel bark from a branch you wish to layer. Surround this wound with damp sphagnum and wrap the lot with a plastic bag pierced with holes and secured with raffia. Mist daily to prevent drying. As soon as roots appear in that ball of sphagnum, repot into a light substrate, half potting compost and half sand. Wait a few months before planting in open ground. This method is ideal for obtaining bonsai with twisted or slightly contorted forms.

By side grafting

On a young Ginkgo biloba on its own roots (that is, species type), you can graft low on the trunk so that afterwards soil conceals the graft union. Make a vertical split of about two centimetres in the rootstock, the Ginkgo on its own roots, using a grafting knife. The idea is to make an incision a few millimetres deep and open this wound by separating the bark. Place into this slit a branch cut on a slant from the variety you wish to reproduce. Wrap with raffia and tie firmly (personally I use large clothes pegs if the rootstock is not too wide, which allows me to remove them and check there is no rot, the main cause of graft failure). This method is perfect for multiplying a specific variety and therefore reserved for professionals or experienced amateurs.

Maintenance, pruning and care of Ginkgo biloba

Care

In early years, keep base of tree relatively moist. But not too much! In short, a simple mulch of herbs or dead leaves and occasional watering if summer is particularly dry, and your Ginkgo biloba will thrive.

Pruning

Although a favourite for bonsai and remarkably tough, even under poor treatment, Ginkgo biloba does not particularly appreciate pruning. If you can avoid it, do so! This will spare your tree unnecessary wounds and an unbalanced structure.

Diseases and pests

To date, no diseases, pests or parasitic organisms are known to affect Ginkgo biloba.

Companion planting and uses

Alone, certainly, but in a handsome setting…

Ginkgo biloba is a marvel simply placed on its own (like a grown-up!) at the centre of a short grass meadow. But… don’t forget to give it a strong backdrop contrast, especially in autumn. In that case, take from your hat (or straw hat) some conifers and evergreens with dark or bluish foliage. For example, this striking Pinus nigra ‘Molette’ or an ever-charming Picea pungens ‘Jeddeloh’ whose bluish thorns will contrast with the golden-yellow autumn foliage of the Ginkgo, and why not a handsome Magnolia grandiflora ‘Alta’ whose dark evergreen foliage will reinforce the soft green of our “tree of forty coins”. Do not place these too close to one another; after all, they are separated by an ocean in their native habitat… To dress the base of your Ginkgo biloba, a tapetum of Pachysandra terminalis is a good idea if your tree gives them enough shade.

Pairing idea: Ginkgo biloba, Picea pungens ‘Jeddeloh’, Magnolia grandiflora ‘Alta’ and Pachysandra terminalis

In a zen corner of the garden

In the quietest corner of your garden, the one where even your annoying neighbour does not dare interrupt your meditation for fear of feeling your wrath: install Ginkgo biloba ‘Blagon’ alongside an Acer shirasawanum ‘Jordan’ with autumn colours as vivid as its companion, a charming Prunus serrulata ‘Amanogawa’ with a habit as fastigiate as its “tree of forty coins” friend and a tapetum of Hakonechloa macra. Your garden has suddenly travelled about 10,000 km to find itself in the Land of the Rising Sun. Moshimoshi!

Example of a Japan-inspired pairing: Ginkgo biloba ‘Blagon’, Acer shirasawanum ‘Jordan’, Prunus serrulata ‘Amanogawa’ and Hakonechloa macra

For a terrace with a chic, contemporary atmosphere

Ginkgo biloba ‘Mariken’ will sit well alongside other Asian companions. The flowering of Camellia botanyuki will brighten your terrace in winter while Ginkgo remains absent. Add striking, architectural foliage in the form of a Fargesia murielae (don’t forget to water it!). We’re still missing seasonal flowers… so add two evergreens: the handsome Escallonia ‘Pink Elle’ with spectacular summer flowering and, for scented presence, a dwarf Choisya ‘White Dazzler’.

Example of a terrace pairing: Ginkgo biloba ‘Mariken’, Camellia ‘Botanyuki’, Fargesia murialae ‘Panda’, Choisya ternata ‘White Dazzle’ and Escallonia laevis ‘Pink Elle’

In a rock garden, lost among a collection of miniature conifers

The adorable Ginkgo biloba ‘Troll’ (what a name!) will look so original amid all those dwarf conifers and evergreens: a Chamaecyparis obtusa ‘Nana’, a Cephalotaxus harringtonia ‘Korean Gold’, an Abies koreana ‘Kohout’s Icebreaker’, a Pinus densiflora ‘Alice Verkade’ and other Cryptomeria japonica… Who said conifers were cumbersome?! A tapetum of Erica carnea will serve as an eye-catching groundcover.

Rock garden pairing idea: Ginkgo biloba ‘Troll’, Cryptomeria japonica ‘Vilmoriniana’, Chamaecyparis obtusa ‘Nana Gracilis’, Abies koreana ‘Kohouts Icebreaker’ and Pinus densiflora ‘Alice Verkade’

Useless anecdotes

• Pseudo-seeds are eaten in Asia, roasted like pistachios once fleshy part has been removed; raw they are toxic.
• Ginkgo’s pale yellow wood is used in cabinetmaking and sculpture.
• Slipping a few Ginkgo leaves into books would keep insects away.
• Plant is also cultivated for medicinal use. Its medicinal properties (venous disorders, cardiac regulator, …) have been known for millennia, although recent studies report a non-significant effect. Research is currently underway into combating Alzheimer’s disease and Parkinson’s disease, with no success so far.
• Surprisingly and exceptionally monoecious Ginkgo (male and female flowers on same tree) can be found in the wild, without any plausible explanation for this phenomenon.
• Its nickname “tree of forty écus” would come from the fact that French botanist Mr de Pétigny allegedly bought from another botanist, an Englishman, five Ginkgo biloba for the staggering sum of 40 écus per tree. (which is undoubtedly much more expensive than in our nursery!)
• It is also called “tree of a thousand écus“, no doubt referring to the golden colour Ginkgo dons in autumn.
• A symbiotic microalga of genus Coccomyxa lives in sym symbiosis within cells of Ginkgo Biloba. This type of endosymbiosis is unique on earth.
• Ginkgo leaf is symbol of Tokyo while tree itself is symbol of… Weimar in Germany.
• tchitchis, these nipple-shaped outgrowths on ageing bark, served as lucky charms for wet nurses and new mothers.