Dr. Bob Gilbert – Columnist
Another curious roadside sighting occurred for us just recently. This time we spotted a large evergreen tree that looks like a fir but is actually a primitive surviving member of the cypress family. This particular specimen is multi-trunked. It is called Cunninghamia and is one of only two species. The species name for this specimen is lanceolata which describes the needles that are lance shaped. Lanceolata is native to China, Vietnam, Laos and Cambodia. The only other species is konishi found in Taiwan. However, newer DNA testing suggests that konishi may be a variety of lanceolate. These two trees were named after a botanist John Cunningham who first described them.
What is remarkable about this tree is its wood. It is quite dense, pale yellow and highly resistance to rot equaling western Redcedar (thuja plicata). As a result, in its native countries it is used for construction of buildings, ships, bridges and the bark is used for roofing. A gray-brown outer bark peels off revealing a red inner bark.
Cunninghamia lanceolate is a large evergreen growing up to 70 feet. It is hardy in zone 7 and happy in most soil types. It produces oddly shaped square brown cones. It also roots easily but if cuttings are taken from horizontal branches they will not grow upright until about five years. This happens with many other trees and shrubs. Vertical branch cuttings grow upright rapidly. Overall it grows in a pyramidal shape. It is remarkable that there are no pest or disease problems known.
The unusual foliage and growth habit creates an exotic appearance. In the 1800s, it was popular for wealthy people to import new and exotic plants from all over the world in order to create a plant zoo. For example, Bartram traveled this area looking for unique plants to send to European collectors. Older arboretums developed during this era and always planted this tree. It makes a beautiful and unique specimen when placed where it can be easily admired.
There are three Cunninghania cultivars that are difficult to find but available. “Glauca” has beautiful waxy blue foliage and maybe a little hardier than the straight species. “Chason Gift” has an excellent pyramidal growth habit. “Greer’s Dwarf’only grows to about six feet and has more of a bronzy foliage look in the winter. Two potential mail order sources are Forestfarm in William, Ore., and Glosler Farm Nursery in Springfield, Ore., both excellent nurseries.
Another curious thing about this plant is that it is only one of two conifers that can be coppiced or cut down to the grown and it will regrow from shoots. Yews will do the same. Cut down or cut off all the foliage of all the other conifer and they die.
Dr. Bob Gilbert is co-founder of Smith Gilbert Gardens in Kennesaw, Ga.
Karen Lawrence is a professional wildlife and botanical photographer from Franklin.