One answer is to plant the primitive ginkgo trees. These romantic trees flourished more than 150 million years ago, and until the 18th century only survived in Buddhist monasteries in China, where they were regarded as sacred. Being unique, they have no enemies, no harmful insects, no disease and no hostile fungal growths. Tall and stately male ginkgo trees have been planted along many American highways. In the autumn their leaves turn bright gold - a wonderful sight. At the first sign of frost they all fall off in one dramatic drop, thus easing the seasonal problem of road-sweeping.
Ginkgo trees are increasing in popularity, but until such time as they are accepted as the ideal city trees conservationists can help to restore the balance by planting young ginkgo trees in their gardens.