Friday, July 1, 2005

A Deciduous Conifer

For many the term deciduous conifer seems to be a misnomer. The thought of a tree losing its foliage yet still considered a conifer is improbable. Often I talk about selecting smaller plants for smaller garden footprints. There are times however, when a large tree, whether evergreen or deciduous, just captures our attention and has us staring in awe. Looking on at some of these majestic creatures has us contemplating age, endurance and historical significance.

Ginkgo biloba, ginkgo, has been around for some 150 million years. Dating back to the Jurassic and Cretaceous periods, a time when dinosaurs ruled, this garden gem inhabited Asia, Europe, and North America. It was not only widespread, but common to these areas. Ginkgo or Maidenhair tree has its common name from its leaves resembling those of Maidenhair Fern (Adiantum). Thought to be extinct, we have German physician and botanist, Engelbert Kaempfer, to thank for his discovery of Ginkgo in Japan in 1691. The curiously shaped leaves of this majestic conifer are distinctive in appearance A link between present and past, this tree can live longer than 3,000 years holding some of times unanswered secrets. Distinctive, two lobed, leaves are somewhat leathery, waxy, and fan shaped with an attached leaf stalk. As a younger tree, Ginkgo, is more open in appearance, however over time it becomes a dense, handsome specimen with spreading rigidly ramified branching. Its bark is gray-brown with even darker furrows. Ginkgo prefers full sun to partial shade and moist, well drained soils. However, you would have to look far to find a tree more adaptable. Known to grow in poor, compacted soils, this tree has endured fungal, insect pests, viral, bacterial diseases, ozone and sulfur dioxide pollution, fire and even radioactive radiation (atom bomb WWII).

Ginkgo comes from the Chinese word Ginkyo or “silver –apricot”, referencing the seed size and appearance to that of an apricot and the silvery bloom of the fruit. When possible, purchase male varieties as you will avoid the unpleasant fleshy seedcoat of the female. The fallen seed of the female has been compared to rancid butter as it decomposes having the presence of butanoic acid, a byproduct of many plants and animals. In the late 1950’s medicine began to catch up to Ginkgo realizing that extracts from the tree can improve blood circulation and memory, thus preventing blood clotting, providing an improved sense of well-being. The leaves are also used in tea for a variety of ailments. In fact the nut has long been used in Chinese medicine for asthma, bronchitis and digestive aid. They are even eaten as a side dish when drinking sake.

Several cultivars and varieties are available today which deviate from their parental giant. Ginkgo b. “Fastigaiata” is an architectural vertical accent that is almost columnar in appearance. “Magyar” is an upright narrow, pyramidal form with clean, green summer leaves. “Princeton Sentry” exhibits uniformed upright branching, remaining narrow over time and is this authors favorite tree. The preceding three cultivars incidentally are all male. Still others are available with spreading characteristics “Pragense” and variegated foliage “Rainbow and Variegata.” A constant of almost all ginkgos is the expected electric fall color display of yellow-gold. Remember while there are smaller types for smaller landscape footprints, Ginkgo biloba will hit 60 to 80 feet some day.

One of the toughest trees you will find, Maidenhair’s application can be a street tree, sited for urban development, used in parks or find a cultivar to hide away in your own garden. A tree of ancient lineage this “golden living fossil” has been revered by Buddhist monks and has its place along side temples. Paleobotanist, Sir Albert Seward (1938) said it best, “It appeals to the historic soul: we see it as an emblem of changelessness, a heritage from worlds too remote for our human intelligence to grasp, a tree which has in its keeping the secrets of the immeasurable past.”