Ginkgo biloba: Ginkgo1
Introduction
Ginkgo is practically pest-free, resistant to storm damage, and casts light to moderate shade. Young trees are often very open but they fill in to form a denser canopy. It makes a durable street tree where there is enough overhead space to accommodate the large size. The shape is often irregular with a large branch or two seemingly forming its own tree on the trunk. But this does not detract from its usefulness as a city tree unless the tree will be growing in a restricted overhead space. If this is the case, select from the narrow upright cultivars such as `Princeton Sentry' and `Fairmont'. Ginkgo tolerates most soil, including compacted, and alkaline, and grows slowly to 75 feet tall or more. The tree is easily transplanted and has a vivid yellow fall color which is second to none in brilliance, even in the south. However, leaves fall quickly and the fall color show is short.
General Information
Scientific name: Ginkgo biloba
Pronunciation: GINK-go bye-LOE-buh
Common name(s): Ginkgo, maidenhair tree
Family: Ginkgoaceae
USDA hardiness zones: 3A through 8A (Figure 2)
Origin: native to eastern China
UF/IFAS Invasive Assessment Status: not assessed/incomplete assessment
Uses: sidewalk cutout (tree pit); street without sidewalk; specimen; urban tolerant; Bonsai; highway median; tree lawn > 6 ft wide; tree lawn 4–6 feet wide
Description
Height: 50 to 75 feet
Spread: 50 to 60 feet
Crown uniformity: irregular
Crown shape: round, pyramidal
Crown density: open
Growth rate: slow
Texture: medium
Foliage
Leaf arrangement: alternate
Leaf type: simple
Leaf margin: lobed
Leaf shape: fan-shaped
Leaf venation: parallel, palmate
Leaf type and persistence: deciduous
Leaf blade length: 2 to 3 inches
Leaf color: bright green
Fall color: yellow
Fall characteristic: showy
Flower
Flower color: green
Flower characteristics: not showy; male—emerges in clusters on 1" long catkins; female—1 ½"–2" long pedicel with 1–2 greenish ovules
Fruit
Fruit shape: oval, round
Fruit length: ¾ to 1 ½ inches
Fruit covering: fleshy, naked seed
Fruit color: tan to orange
Fruit characteristics: does not attract wildlife; not showy; fruit/leaves a litter problem; emits a pungent odor some find to be offensive
Fruiting: fall, and matures after a frost
Trunk and Branches
Trunk/branches: branches droop; showy; typically one trunk; no thorns
Bark: gray brown with textured ridges, becoming deeply furrowed with age
Pruning requirement: little required
Breakage: resistant
Current year twig color: brown, gray
Current year twig thickness: medium, thick
Wood specific gravity: unknown
Culture
Light requirement: full sun to partial shade
Soil tolerances: clay; sand; loam; alkaline; acidic; well-drained to occasionally wet
Drought tolerance: high
Aerosol salt tolerance: moderate
Other
Roots: not a problem
Winter interest: yes
Outstanding tree: no
Ozone sensitivity: tolerant
Verticillium wilt susceptibility: resistant
Pest resistance: free of serious pests and diseases
Use and Management
Female plants are wider-spreading than the males. Only male plants should be used as the female produces foul smelling fruit in late autumn. The only way to select a male plant is to purchase a named cultivar including 'Autumn Gold', 'Fastigiata', 'Princeton Sentry', and 'Lakeview' because there is no reliable way to select a male plant from a seedling until it fruits. It could take as long as 20 years or more for ginkgo to fruit.
Ginkgo may grow extremely slow for several years after planting, but will then pick up and grow at a moderate rate, particularly if it receives an adequate supply of water and some fertilizer. But do not overwater or plant in a poorly-drained area. Be sure to keep turf several feet away from the trunk to help trees become established. Very tolerant of urban soils and pollution, ginkgo could be used more in USDA hardiness zone 7 but is not recommended in central and southern Texas or Oklahoma due to summer heat. Adapted for use as a street tree, even in confined soil spaces. Some early pruning to form one central leader is essential.
There are several cultivars: 'Autumn Gold'—male, fruitless, bright gold fall color and rapid growth rate; 'Fairmont'—male, fruitless, upright, oval to pyramidal form; 'Fastigiata'—male, fruitless, upright growth; 'Laciniata'—leaf margins deeply divided; 'Lakeview'—male, fruitless, compact broad conical form; 'Mayfield'—male, upright fastigiate (columnar) growth; 'Pendula'—pendent branches; 'Princeton Sentry'—male, fruitless, fastigiate, narrow conical crown for restricted overhead spaces, popular, 65 feet tall, available in some nurseries; 'Santa Cruz'—umbrella-shaped, 'Variegata'—variegated leaves.
Propagation is by seed or grafting males.
Pests and Diseases
This tree is pest-free and considered resistant to gypsy moth.
Reference
Koeser, A. K., Hasing, G., Friedman, M. H., and Irving, R. B. 2015. Trees: North & Central Florida. Gainesville: University of Florida Institute of Food and Agricultural Sciences.