Their glowing yellow leaves will light up your landscape in autumn
Few things draw the eye like butter yellow ginkgo leaves against a blue sky. The fan-shaped leaves, backlit by the sun, appear to glow from within, turning the tree into an incandescent force in the landscape.
Then one chilly morning, the scene changes. The same yellow leaves flutter to the ground nearly all at once, leaving a shapely, bare-branched tree that stands like sculpture in a shimmering golden pool. Ginkgo, you realize, has a terrific sense of drama.
During the Jurassic era, several kinds of ginkgo dominated temperate forests over most of the planet (dinosaurs knew these trees well). Their elegant leaves eventually fossilized in places like Washington's Ginkgo Petrified Forest State Park. Today only one species survives ― Ginkgo biloba, or maidenhair tree ― the sole representative of its genus, family, and order.
To gardeners, ginkgo is an indispensable part of the landscape, thriving almost everywhere in the West except in Hawaii, the coldest parts of Alaska, and the most hostile corners of Southwestern deserts (Sunset climate zones 11 and 13).
No other tree is so dependable for fall color over such a wide geographic range, with leaves that turn clear yellow each autumn even in places that get little winter chill. Nearly devoid of insect and disease problems, it's also unfazed by polluted air.
Maybe that's why the ginkgo is so long-lived; some specimens have grown in temple gardens in China and Japan for at least a millennium.
Most ginkgo varieties sold in nurseries are fruitless male trees ― a good thing, since the female tree's plum-size, silvery orange fruits can be messy, and they smell like rancid butter. Large, thin-shelled ginkgo seeds are edible, but not widely appreciated outside Asia. Selected varieties come in standard, weeping, and columnar forms.
Look for trees at nurseries this month ― their leaves are coloring ― in 1-, 2-, and 5-gallon containers, or order by mail from ForestFarm (www.forestfarm.com). Planted in deep, well-drained soil, ginkgo trees typically grow 25 feet tall in 20 years, topping out at 50 to 100 feet when mature. Given perfect conditions, though, they can grow 3 feet a year and, with enough time, can reach 200 feet (spreading half to two-thirds as wide). When the leaves carpet your lawn, gather a handful of the tiny golden fans to scatter down the center of a dining table.
How to grow ginkgo
Choose the right variety. Maidenhair trees come in so many varieties, you're sure to find one that fits your landscape: 'Autumn Gold', a classic variety, reaches 40 feet; leaves are more golden in fall than similar 'Saratoga'. 'Chi Chi' grows to just 5 feet in 10 years, good for a large container. 'Fairmount' is narrow but pyramidal, has so-so fall color. 'Pendula' spreads wider than tall and droops at the tips, giving it a weeping look; slow growing. 'Princeton Sentry' is columnar, can reach 50 feet tall and 10 to 20 feet wide.
Get it off to a good start. Plant a ginkgo in deep, loose, well-drained soil, in a spot that gets full sun. Water regularly until it reaches about 20 feet tall, then cut back to occasional irrigation. During the tree's first few years in your garden, cut back any awkward branches and vertical shoots growing parallel to the central leader during winter dormancy.