Professional artist and co-worker Jessie Lyons loved to portray the beauty of nature, and one day she showed me some of her paintings. I found it interesting when she shared that she had pictures of scenes more incredible than the paintings I was shown, but considered them too unreal to paint. She said her experience was that people are not drawn to nature paintings that appear unrealistic. I thought of Jessie when I saw the trees in the picture to the right, shaped like ice cream cones. Would she consider these trees too unusual to be accepted as realistic if she painted them? Not many years ago, she probably would. However, after discovering these trees lining the front of Bethany UMC in Smyrna, seeing one in front of Cactus car wash in Douglasville, and finding many more in landscapes west and north of Atlanta, it is apparent that these trees are becoming common in our environment, and usual.
The trees that got my attention are shaped as inverted, or upside-down, cones on a stick. Another way to describe this shape is vase-shaped (or V-shaped). Crown edges are straight as if trimmed. Thanks to the knowledgeable assistance of Parks Kennerly of Nature’s Supply Centre in Mableton, I found the trees’ name to be ‘Green Vase’ Japanese Zelkova. Its scientific name is Zelkova serrata ‘Green Vase’, and it is a member of the family Ulmaceae. This cultivar was patented by Princeton Nurseries in Princeton, New Jersey in 1983.
The family Ulmaceae has 7 generally accepted genera, among them the elms (genus Ulmus) and the zelkovas (genus Zelkova). These can be distinguished by comparing leaves and seeds. Elm leaves are uneven at the base, while Zelkova serrata leaves are symmetrical. Also, elm seeds have wings, and Zelkova serrata seeds have no wings. Zelkovas were once common throughout northern Europe and North America as late as the Pliocene era, but glaciation drove those in North America to extinction and confined those in Europe to isolated areas. Zelkova serrata and two other species remained in eastern Asia, while only one remained in southwestern Asia, one in Sicily, and one in Crete.
The Zelkova serrata species prefers full sun and moist, well-drained soil. It tolerates some drought, and most urban conditions. The USDA rates this species as generally suitable for zones 5B to 8, where minimum average temperatures can be between -20 and -10 degrees F. This includes the North Central United States and portions of New England, extending south to the Florida panhandle. Tree growth is rapid when young, then slows to a medium rate. Trees can grow 50 to 100 feet, depending on the variety or cultivar. Many live for centuries.
Zelkova serrata’s many attractive varieties and cultivars have become popular as street trees and in general landscaping. They make good shade trees. Roots are not usually a problem. The trunk of the tree is attractive, with many features that are similar to Japanese flowering cherries. The bark when young is gray and smooth, with scattered brown lenticels that appear as horizontal marks. The bark peels slightly with age, exposing orangish inner bark. The short trunk divides into many upright and spreading branches, which form a broad, round-topped head. The crown is generally vase-shaped, but depending on the variety or cultivar, it may be broad, spreading, narrow, or anything in between. Leaves are alternate, medium green, less than 3 inches long, oblong-elliptic, symmetrical, and serrated. Serrations could be pointed or rounded. Leaves have rounded bases and pointed tips. Autumn leaf colors are yellows, oranges, and reds. Petioles are 1/16 to 3/16 inches long. In March to April, as leaves appear, Zelkova serrata produces yellow-green male and female flowers, which are small and inconspicuous. These give way to nut-like seeds or drupes, which are ovate and wingless, and about 1/8 inch in diameter. These drupes ripen to brown in autumn, and are not ornamentally important. Propagation is by seeds, cuttings, or bud-graftings, and these trees are not considered invasive.
The varieties and cultivars of Zelkova serrata have forms and sizes that give landscapers many options. One cultivar, ‘Haika’, is considered the fastest-growing and largest, with an open and loose habit. Another cultivar, ‘Wireless’, is broad-spreading and appropriate for utility wire locations. The following list of cultivars from Wikipedia.org is far from complete, but indicates the number and variety available:
- ‘Fuiri Keyaki’ (variegated leaves)
- ‘Goblin’ (dwarf)
- ‘Goshiki’ (variegated leaves) This variegated form features leaves splashed or dusted with creamy white. This plant grows fairly well.
- ‘Green Vase’ (tall, narrow crown)
- ‘Green Veil’ (pendulous branchlets)
- ‘Iruma Sango’ (fastigiate)
- ‘Nire Keyaki’ (semi-dwarf)
- ‘Pulverulenta’ (variegated leaves)
- ‘Spring Grove’ (upright crown)
- ‘Variegata’ (variegated leaves) This variegated form features a white rim around the leaves, but it is a weak grower.
- ‘Village Green’ (grows more rapidly than ordinary seedlings and develops a straight smooth trunk. Hardier than trees of Japanese origin)
- ‘Parkview’ (selection with good vase-shape, size similar to species)
- ‘Urban Ruby’ (red autumn color)
- ‘Musashino’ (tightly columnar in form, fast growing)
- ‘Ogon’ (Bright green-yellow almost gold colored leaves all year, with a contrasting bronze colored bark)
My personal favorite, ‘Green Vase’ Zelkova, often known as ‘Green Vase’ Japanese Zelkova, has a narrow, upright crown that forms a V-shape. The trunk grows straight to about head height, and then explodes in a profusion of upright branches that do not droop, maintaining a vase shape. It has a very attractive form for street use, and is especially useful for places that have limited width for the crown. As a shade tree, no limbs get in the way of passers-by. Trees planted together appear very uniform, and can be spaced to form a very attractive street canopy. Bark has attractive characteristics, and autumn leaf color is orange, bronze and red. A fast to medium grower, the tree grows to about 70 feet tall and 35 to 40 feet wide. This is perhaps the most popular Zelkova cultivar.
Until I noticed the ‘Green Vase’ Zelkovas in front of Bethany UMC in Smyra, I knew nothing of Zelkova serrata with its many varieties and cultivars. I had mistaken many I had seen for elms. These trees are becoming increasingly used on streets, in parking buffer strips, in parks, on campuses, and as shade trees on lawns. One should become familiar with this increasingly popular tree.