Like me, Ginkgo biloba is a living fossil, or as Sunset summarizes, an "ancient survivor from prehistoric times..." (p. 339). The current understanding is that this is the last of its kind, the only genus in the family Ginkgoaceae. The other two genera, Ginkgoites and Baiera are extinct, so we should treat this tree with extra care and kindness. Not that it is difficult to grow; they have lived this long without us. Still, our urban environments can challenge the hardiest species; ideally, we should provide them with optimal conditions for their long-term health.
Growing up in Palo Alto, I would ride my bike to school past stately homes adjacent to a well-known neighborhood, Professorville. While Professorville was and is populated with Craftsman homes, the southerly neighborhood still has the imposing homes that I remember so long ago. One in particular, the Seale House, caught my eye in autumn; not for the homes grandeur but for the Gingko biloba tree proudly ascending high above, perfectly scaled for a three story home. As I rode by on those brisk autumn mornings, I would monitor the tree for when it was ready to turn color, then suddenly there it was ablaze in gold. Ginkgos turn quickly, linger for only a little while in the shortening daylight, then whoosh! The leaves fall almost as quickly as they turned, carpeting the lawn as if Mother Nature herself placed every golden leaf. I sometimes walk this neighborhood today, hoping no one will notice the creepy old guy enjoying the leafy landscape. Walking and observing is about memories as well as seeing really great plant specimens, as this tree represents.
The above example is how maidenhair trees should be treated, an open setting with plenty of rooting space and moisture. When this unusual member of the gymnosperms was first discovered in its last habit within China, where rain persists, we can assess that their preference is for moist landscapes. Unfortunately for California, our arid and dry soils do not lend to their best performance unless the soil and irrigation is thoroughly modified. As street trees with limited rooting space and compacted urban soils, Gingko bilobas may struggle in ways they hadn't experienced before. Despite these challenges, several references mention its tolerance for drought, pollution and urban spaces.
Thankfully, there are some cultivars that lend themselves to smaller spaces, although ideally the soil will be improved much further beyond the confinement of a tree well. Here are a few of those smaller cultivars:
'Autumn Gold': Increasingly specified as a street tree within the City of San José, will reach 45' tall by 35' wide. An introduction by the former Saratoga Horticulture Foundation.
'Fairmont': Taller, reaching up to 75' while maintaining a narrower habit at 25'.
'Fastigiata': Also 75' tall but even narrower than 'Fairmont' at only 15' wide.
'JFS-UGA2' (Golden Colonnade™): Not as common reaching 45' tall but only 25' wide.
'Halka': A midsized tree at 45' tall and almost as wide at 40'.
'The President' (Presidential Gold®): Also not as common and can become wide, about 50' tall by 40' wide.
'Princeton Sentry': Becoming popular for tighter urban spaces, reaching 50' tall by only 20' wide.
'Saratoga': Striking foliage unlike the others, which is pendulous and small. May be a dwarf topping out at 24' tall and only 10' wide. Another introduction by the former Saratoga Horticulture Foundation.
West Valley College Campus Location: Ginkgo biloba
Science & Math, west patio
Lat: 37°15'55.47"N
Long: 122° 0'35.96"W
Overall summary and leaf explanation by North Carolina University:
facts
Botanical Name: Ginkgo biloba
Ginkgo: Chinese, yinxing, for silver apricot for its edible seed. The Royal Horticulture Society further explains, "when translated to Japanese, it is ginkyo, but Linneaus misread the name, switching the 'y' for a 'g,' giving the current spelling" (p. 142)
Biloba: Two-lobed leaves
Common Name: Maidenhair tree
Family Name: Ginkgoaceae
Origin: China
design considerations
Positioning: Background, feature
Garden Themes: Autumn interest, Asian-inspired, formal, children, drought
Uses: Shade, street tree/allée, commercial, park/open space, specimen, accent, lawn
identifying characteristics
Type: Deciduous tree
Form: Pyramidal (form varies with cultivars)
Texture: Medium
Size: 75'-100' tall by 35'-50' wide
Outstanding Feature(s): Fall color, form
Bark: Light gray, fissured
Leaf:
Type: Simple
Arrangement: Sinistrorse
Shape: Flabellate (fan shape)
Margin: Irregular wave, may have a single lobe division
Color: Emerald green turning bright golden yellow in autumn
Surface: Glabrous, slightly dull
Flower: Spring. Inconspicuous, green to cream; male produces a pollen cone
Fruit: Autumn. Technically, not a fruit...resembles fruit with seed: fleshy, messy when dropping, odorous. Most nurseries only grow male forms because of the undesirable odor of female trees.
cultural requirements, tolerances & problems
Sunset Zones: A3; 1-10, 12, 14-24
USDA Zones: 3-9
Light: Full sun
WUCOLS SF Bay Area Hydro Zone: Moderate
Soil:
Texture: Sand, loam, clay if well composted
Moisture Retention: Well-drained. Accepts periods of dryness with intermittent deep watering.
pH: Highly acidic to highly alkaline
Tolerances: Drought, heat, pollution, salt, deer
Problems: Fruit drop may be messy with unfavorable smell.
Branch Strength: Strong
Insects: Not recorded at time of posting
Disease: Anthracnose
cultural interests
citations & attributions
Bayton, R. (2019). The Royal Horticultural Society's the Gardener's Botanical: An Encyclopedia of Latin Plant Names. London: Mitchell Beazley.
Extension Gardener. "Ginkgo biloba." North Carolina State University, Raleigh. Accessed on October 17, 2021, from https://plants.ces.ncsu.edu/plants/ginkgo-biloba/.
Norris Brenzel, K. (Ed.). (2012). The New Sunset Western Garden Book. New York: Time Home Entertainment, Inc.
Plant Finder. "Ginkgo biloba." Missouri Botanical Garden, St. Louis. Accessed on October 17, 2021, from https://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?kempercode=z990.
SelecTree. UFEI. "Ginkgo biloba Tree Record." 1995-2021. Cal Poly State University, San Luis Obispo. Accessed on October 17, 2021, from https://selectree.calpoly.edu/tree-detail/657.
Water Use Classification of Landscape Species. "WUCOLS IV Plant List." University of California, Division of Agriculture and Natural Resources, Davis. Accessed on October 17, 2021.
Photos:
Green tree: "Ginkgo biloba 001" by H. Zell is licensed under Creative CommonsAttribution-Share Alike 3.0 Unported.
Male flowers detail: "Ginkgo biloba - male flower" by Marcin Kolasiński is licensed under Creative Commons Attribution-Share Alike 4.0 International, 3.0 Unported, 2.5 Generic, 2.0 Generic and 1.0 Generic.
Feature leaves photo by TELCS
Mature trunk detail photo by TELCS
Sample branch photo by TELCS
Park photo by TELCS
All other photos purchased at Shutterstock
Kommentare