Ginkgo or Maidenhair Tree

(Ginkgoaceae - Ginkgo Family)

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• Form
  • large shade tree
  • the species form usually matures at about 80' tall by 60' wide under urban conditions, but specimen trees in open areas can get much, much larger
  • an upright columnar, sparsely branched, and open growth habit in youth, usually becoming an upright oval to upright spreading growth habit with maturity, but sometimes becoming highly irregular and picturesque in its branching with age
  • medium growth rate

• Culture
  • full sun to partial sun
  • prefers moist, deep, sandy soils in full sun, but is very adaptable to stressful situations, including poor soils, compacted soils, various soil pHs, heat, drought, Winter salt spray, and air pollution (and is therefore very urban tolerant)
  • propagated primarily by cuttings from male cultivars grafted onto seedling rootstock, but also propagated by seed (where the gender of the offspring is often not visually determined for at least twenty years)
  • Gingko Family, being virtually free of disease and pest problems
  • moderate availability in ball and burlap form

• Foliage
  • medium green and unusually obovate (fan-shaped), up to 3" long, with a petiole that is also up to 3" long; this shape and the elongated petiole cause the foliage to flutter in the slightest breeze
  • alternate along the terminal stems, but clustered on the numerous short spur shoots
  • the leaf blade apex is sometimes entire, but often has a single vertical slit in the top center (hence the specific epithet biloba); rarely, two slits occur, yielding three lobes
  • veins are slightly raised (giving a ribbed appearance to the foliage) and usually dichotomous (forked)
  • fall color is usually chartreuse, but may be golden-yellow in excellent years, or yearly with certain cultivars selected for dependable fall color

• Flowers
  • dioecious (male and female flowers are borne on separate trees, with cultivars selected for male fruitlessness)
  • pendulous catkins on male trees pollinate the pendulous pistillate flowers on 2" peduncles on female trees in March and April
  • this species may not flower (and therefore also may not fruit) until it is about twenty years old

• Fruits
  • on female trees, the tan-orange oval fruits are pendulous from the spur shoots, often produced in great abundance and becoming an abscising mushy mess in September and October, covering the ground with fleshy, strongly malodorous fruits
  • for this reason, male clones grafted onto seedling understock are preferred as landscape trees; alternatively, the placement of a tree of unknown gender away from public access areas is the proper course of action

• Twigs
  • stout, with many short spur shoots occuring along the older stems and branches
  • stems are tan, light brown, or gray, becoming thready on second-year stems
  • the relatively smooth tan branches are somewhat reflective in the Winter sun

• Trunk
  • the light brown to brownish-gray bark is deeply furrowed and highly ridged with age
  • the tree usually loses its central leader and gives rise to several vertical trunks that keep ascending to great heights
  • trunk may get up to 3' or more in diameter with age

• ID Summary
  • the sparsely-branched, upright, gawky appearance of youth fills in with age, maturing to a very tall but still spreading tree of massive potential size, having a thick, furrowed and ridged bark and many bold branches containing numerous branchlets and spur shoots
  • leaves are fan-shaped, dichotomously ribbed, on long petioles, and usually have a slit in the middle of the upper leaf blade, fluttering in the breezes
  • trees are dioecious, with female trees bearing interesting oval pendulous fruits that mature to a mushy, abscising mess in Autumn, being quite malodorous, but not bearing fruit until after about twenty years of age

• Function
  • shade, specimen, or focal point tree
  • sometimes incorrectly used as a street tree due to its extreme urban tolerance, but much too big (even in stunted and columnar cultivar form) for this usage

• Texture
  • bold texture in foliage and when bare
  • open to thick density in foliage and when bare, due to the widely-spaced main branches and the density of mature trees versus the openness of saplings

• Assets
  • long-lived shade tree, often maturing at a very large size
  • very urban tolerant
  • bold texture, with a growth habit of great character
  • leaves flutter in the slightest breeze
  • fall color on selected cultivars is a clear solid yellow

• Liabilities
  • female trees have copious fruits that are quite messy upon abscising into pedestrian areas, and are very malodorous
  • growth can become irregular or get out-of-hand in restricted areas with age, including its very large, tall, and spreading habit with maturity, plus the tendency of some trees to have branches crossing the trunk; definitely not a shade tree for the small urban yard

• Habitat
  • zones 3 to 8
  • native to China

• Alternates
  • large, urban-tolerant shade trees (Corylus colurna, Gleditsia triacanthos inermis, Platanus x acerifolia, Populus deltoides, Quercus rubra, etc.)

• Variants
  • cultivars are always selected for non-fruiting character (male trees); thereafter, for better fall color and/or modified growth habit
  • Ginkgo biloba 'Autumn Gold' - more dependable golden-yellow fall color, with a broadly pyramidal growth habit at maturity; male, with more compact form, maturing at about 50' tall by 30' wide
  • Ginkgo biloba 'Princeton Sentry' - nearly columnar form, being slightly wider at the base, used architecturally for a vertical accent; male, about 70' tall by 10' wide

• Translation
  • Ginkgo is derived from the Japanese word ginkyo, meaning "silver apricot", referring to the fruit, which is eaten in Japan.
  • biloba translates as "two-lobed", referring to the split-in-the-middle character of its fan-shaped leaf blades.
  • once thought to be extinct, Ginkgo was discovered in China in the mid-1700s and is now dispersed throughout the world, having lived on Earth for over 150 million years.

• Purpose
  • Ginkgo is a large picturesque tree at maturity, grown for its shade, large size, and bold accent in the landscape.

• Summary
  • Ginkgo biloba can grow to be a huge, bold-textured, urban-tolerant shade tree that is also one of the oldest trees still living on Earth, actually a deciduous gymnosperm by botanical classification.