Plant notes: Gingko

Gingko tree in autumn in City Park, Launceston, Tasmania

Plants in permaculture design

Using biological resources to fullfill the needs of both people and natural systems is one of permaculture’s design principles. Bill Mollison, one of the originators of the design system, described this as working with, not against, nature. Everything gardens, Bill wrote in saying that living things alter their environments to suit their needs.

When selecting species for use in design, consider:

• plant suitability for our climate
• how plants would benefit people and their environments
• multiple roles for plants — food, windbreak, habitat, fuelwood, environmental modification, psychological, aesthetic etc
• where to best locate the plant in a planting plan
• any cautions such as toxicity, irritability, allergenic properties, potential for spread in ecosystems.

Gingko

COMMON NAME:

• Gingko
• Maidenhair tree.

SPECIES/BOTANIC NAME: Gingko balibo

ORDER: Gingkoaceae.

GENUS: Gingko.

CENTRE OF DIVERSITY: China.

GROWTH FORM:

• deep rooted tree to 20–35m
• lobed leaves to 10cm radiating out into the leaf blade
• leaves turn a bright yellow in autumn, then fall.

The lobed leaves of gingko in autumn.

USES:

1. Used in traditional Chinese medicine to treat ailments such as dementia, asthma, bronchitis, and kidney and bladder disorders and as a dietary supplement. Claims that extract of ginkgo leaf enhances cognitive function are not supported by evidence. Using leaf extracts in moderate quantities appears to be safe, however use as a dietary supplement for health or for disease treatment is not supported by evidence (National Center for Complementary and Integrative Health, US National Institutes of Health. 1 August 2020).
2. Traditional Chinese food. Nut-like gametophytes inside the seeds are used in food preparation. May become toxic if eaten in large quantities over long period.
3. The disease and insect resistant wood of the gingko is used in furnture and craft production.

USEFUL PART:

1. Leaf.
2. Seed.
3. Wood.

REPRODUCTION:

• wind pollinated
• dioecious — trees of separate sexes with male trees producing pollen in small cones and female trees producing 1.5–2cm long seeds.
• prefers full sun, well-watered and well-drained soils.

CAUTION:

1. Side effects of using ginkgo supplements may include increased risk of bleeding, gastrointestinal discomfort, nausea, vomiting, diarrhea, headaches, dizziness, heart palpitations and restlessness.
2. Pollen may produce allergic reactions (leaves contain allergenic ginkgolic acids).
3. Seeds eaten in large quantities over longer period may induce poisoning.

HISTORY:

Ginkoaceae, the botanical order to which gingko belongs, first appeared in the Permian era of 270 million years ago.

The genus is known from fossils and first appeared in the Middle Jurassic around 165 million years ago, before the era of flowering plants.

Globally widespread in deep time, gingko’s range diminished until by around two million years ago it was restricted to a small area of China, the only location where it grows in the wild. It is now cultivated around the world.

PHOTOS:

Young gingko tree in City Park, Launceston, Tasmania-Lutruwita. Climate — cool temperate.

Photos show gingko as foliage turns yellow prior to falling in autumn.

Photos ©Russ Grayson.

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