Ginkgo biloba, also called maidenhair, is a broadleaf, deciduous tree. While it loses its leaves in winter, it is classified as a conifer and is dioecious, meaning that some trees are male while others are female. Native to China, ginkgo biloba trees, broadly speaking, will grow well in planting zones 4 through 9.
The gingko biloba's uniquely fan-shaped leaves start out green but change to golden-yellow in the fall. Before the whole leaf turns golden, there is sometimes a stage during which the leaf is two-toned, with separate bands of gold and green. The common name "maidenhair" was inspired by the fan shape of the leaves, which reminds people of the maidenhair fern (Adiantum spp.). The bark on older specimens of the tree becomes deeply furrowed.
|Botanical Name||Gingko biloba|
|Plant Type||Deciduous tree|
|Mature Size||50 to 80 feet tall and 30 to 40 feet wide|
|Sun Exposure||Full sun to part shade|
|Soil Type||Sandy, well-drained|
|Soil pH||5.0 to 8.0|
|Flower Color||Green (insignificant flowers)|
|Hardiness Zones||4 to 9|
How to Grow Gingko Biloba
Most of the recommended cultivars of gingko biloba grow best in full sun in the North (partial sun in the South), have average water needs, and stand up well to pollution and road salt. In fact, as salt-tolerant plants, they are good choices for those who landscape near the ocean. All bear golden fall foliage, as well.
Many types of ginkgo start out narrow while young but then become quite wide as they age. You can slow down this process a little by pruning them while young so as to force them to produce a single leader. But a much better solution is to select a cultivar known to have a narrow shape.
Plant ginkgo biloba in an area that receives full sun to part shade.
The ginkgo is not fussy about soil type or most soil conditions and will tolerate both acidic and alkaline soil as well as compacted soil. It prefers well-drained sandy soil or loam.
Water as needed to keep the soil moist, provided the site is well-drained. Moisture is particularly important when the tree is young; it is relatively drought-tolerant at maturity.
Temperature and Humidity
Ginkgo bilobas are commonly grown in urban sites in many regions, proving their tolerance of a wide range of moisture conditions and temperatures. However, they can struggle in hot, dry climates.
Young ginkgo biloboa trees can benefit from a spring feeding of tree fertilizer. Mature trees typically do not need to be fed.
Ginkgo biloba trees are attractive enough to be used as specimen plants in your landscaping, particularly because of their golden fall foliage color. They are more tolerant of compacted soil than many other types of trees. They are also disease-resistant and tolerate urban pollution. All of these qualities—along with their small leaves—make them good choices for planting along city streets, where they can grow into tall shade trees. At the other end of the spectrum, they are also used for Japanese bonsai.
Whether for city streets or for people's yards, the male trees are preferred (unless you have allergies), because they are fruitless. Female trees bear a fruit-like product (actually a seed ball) that not only emits a foul odor but also is slippery when it drops down on sidewalks or driveways. Cleaning up after female Ginkgo biloba trees is a high-maintenance task. The problematic "fruit" is about the size of a cherry tomato. Fortunately, all-male cultivars have been created through grafting. Buying one of these cultivars gives you a way to experience the beauty of the tree while avoiding the mess.
Varieties of Male Ginkgo Biloba Trees
- 'Autumn Gold' (zones 3 to 8) is a popular male cultivar. It grows to 40 to 50 feet tall, with a spread of 25 to 30 feet and has a broadly spreading canopy.
- 'Saratoga' (zones 4 to 8) has a similar size and shape to 'Autumn Gold'. What makes this cultivar different is the V-shape of its leaves, which strays from the usual fan shape.
- ‘Fastigiata' (zones 3 to 8) is another popular male cultivar and is a good choice if you want a tree that is narrow (column-shaped). It becomes 30 to 50 feet tall but just 10 to 15 feet wide.
- 'Princeton Sentry' (zones 3 to 8) is also columnar but matures somewhat larger, at 40 to 50 feet tall and 20 to 30 feet wide.
- 'Fairmont' (zones 5 to 8) is a tall, skinny tree, reaching at least 50 feet in height but just 15 to 18 feet across.
- 'Pendula' (zones to 8) is a good choice for a small space. It's a slow-growing male cultivar that has a stocky build and reaches just 8 feet tall at maturity, with a maximum spread of 10 feet. While the cultivar name 'Pendula' usually suggests a weeping form, in this case, the tree is more umbrella-shaped.
Toxicity of Gingko Biloba
Ginkgo is perhaps best known in the Western world for the supplements and other health products made from this tree. Most of these are made from the leaves rather than the seeds (or "nuts"). While people in China and other cultures have historically used ginkgo medically and even eaten ginkgo seeds, this comes with potentially significant health concerns.
Ginkgo seeds are toxic and should not be eaten in either raw or roasted forms. The seeds can be made relatively safe through proper preparation, but it's best to play it safe and avoid eating the seeds altogether.
Ginkgo extracts and supplements can be harmful to some people and can interact adversely with a number of conventional medications. The Mayo Clinic reports that benefits of ginkgo to prevent dementia or reduce claudication (too little blood flow) are not supported by sufficient evidence.
The Mayo Clinic advises against the use of ginkgo for people with epilepsy or bleeding disorders and for pregnant women. It also lists several medications that can be adversely affected by ginkgo, including antidepressants, statins, diabetes drugs, and ibuprofen.