Fact Sheet ST-678October 1994

Zelkova serrata ‘Green Vase’

Figure 1. Young ‘Green Vase’ Japanese Zelkova.

‘Green Vase’ Japanese Zelkova 1

Edward F. Gilman and Dennis G. Watson2

INTRODUCTION

‘Green Vase’ somewhat resembles the vase shapeof American Elms, is more upright in habit andtolerant of pollution, makes a great city street tree andproduces a taller and narrower tree than ‘VillageGreen’ Zelkova (Fig. 1). Zelkova is often listed as areplacement for American Elm since it has roughly thesame vase shape and grows 70 to 80 feet tall with a 50to 60-foot spread. But no tree will truly match thegrace and elegance of the American Elm. Zelkova ismassive, with the trunk capable of growing to four feetor more in diameter. It has a moderate growth rateand likes a sunny exposure. Branches are morenumerous and smaller in diameter than American Elm.Major branches grow very upright and provide easyclearance for tall vehicles below making it quitesuitable as a street tree. Leaves are 1.5 to 4 incheslong, turning a brilliant burnt umber in the fall.

GENERAL INFORMATION

Scientific name: Zelkova serrata‘Green Vase’Pronunciation: zell-KOE-vuh sair-AY-tuhCommon name(s): ‘Green Vase’ Japanese Zelkova,‘Green Vase’ Saw-Leaf ZelkovaFamily: UlmaceaeUSDA hardiness zones: 5B through 8 (Fig. 2)Origin: not native to North AmericaUses: large parking lot islands (> 200 square feet insize); wide tree lawns (>6 feet wide); medium-sizedparking lot islands (100-200 square feet in size);medium-sized tree lawns (4-6 feet wide);recommended for buffer strips around parking lots orfor median strip plantings in the highway; shade tree;

sidewalk cutout (tree pit); residential street tree; treehas been successfully grown in urban areas where airpollution, poor drainage, compacted soil, and/ordrought are commonAvailability: generally available in many areas withinits hardiness range

1. This document is adapted from Fact Sheet ST-678, a series of the Environmental Horticulture Department, Florida Cooperative Extension Service,Institute of Food and Agricultural Sciences, University of Florida. Publication date: October 1994.

2. Edward F. Gilman, associate professor, Environmental Horticulture Department; Dennis G. Watson, associate professor, Agricultural EngineeringDepartment, Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida, Gainesville FL 32611.

Zelkova serrata ‘Green Vase’ -- ‘Green Vase’ Japanese Zelkova Page 2

DESCRIPTION

Figure 2. Shaded area represents potential planting range.

Height: 60 to 80 feetSpread: 50 to 60 feetCrown uniformity: symmetrical canopy with aregular (or smooth) outline, and individuals have moreor less identical crown formsCrown shape: vase shapeCrown density: moderateGrowth rate: fastTexture: fine

Foliage

Leaf arrangement: alternate (Fig. 3)Leaf type: simpleLeaf margin: serrateLeaf shape: oblong; ovateLeaf venation: pinnateLeaf type and persistence: deciduousLeaf blade length: less than 2 inchesLeaf color: greenFall color: copper; redFall characteristic: showy

Flower

Flower characteristics: inconspicuous and notshowy; spring flowering

Fruit

Fruit shape: ovalFruit length: < .5 inchFruit covering: dry or hardFruit characteristics: does not attract wildlife;inconspicuous and not showy; no significant litterproblem

Trunk and Branches

Trunk/bark/branches: grow mostly upright and willnot droop; showy trunk; should be grown with a singleleader; no thornsPruning requirement: requires pruning to developstrong structureBreakage: susceptible to breakage either at the crotchdue to poor collar formation, or the wood itself isweak and tends to breakCurrent year twig color: brownCurrent year twig thickness: thin

Zelkova serrata ‘Green Vase’ -- ‘Green Vase’ Japanese Zelkova Page 3

Figure 3. Foliage of ‘Green Vase’ Japanese Zelkova.

Culture

Light requirement: tree grows in full sunSoil tolerances: clay; loam; sand; slightly alkaline;acidic; occasionally wet; well-drainedDrought tolerance: highAerosol salt tolerance: moderate

Other

Roots: surface roots are usually not a problemWinter interest: no special winter interestOutstanding tree: tree has outstanding ornamentalfeatures and could be planted moreInvasive potential: little, if any, potential at this time

Verticillium wilt susceptibility: not known to besusceptiblePest resistance: long-term health usually notaffected by pests

USE AND MANAGEMENT

Unfortunately, the branches on Zelkova are oftenclumped together on the trunk at one point. Doubleand multiple trunks or leaders with embedded bark arealso common. This is not a desirable form forplanting in urban areas and needs to be prevented, orcorrected, on existing trees. Purchase trees withbranches spaced along the trunk so they can develop asecure hold onto the trunk. These will be hard to findbut insist on it! Be sure that branches remain less thanabout half the diameter of the trunk to maintain astrong, durable form. Encourage nurserymen to growtrees with good trunk and branch structure.

The tree will tolerate most soil types, includingthose with a pH to about 7.5, but prefers a moist deeploam. It is reportedly risky to transplant in the fall.Established trees are fairly drought-tolerant, requiringlittle irrigation unless located in sandy soil. It makes awonderful street tree even in restricted-soil tree pits,and is almost pest free. The crowns will eventuallygrow together if trees are planted on 30-foot-centers,forming a wonderful shaded street. This is a tough,urban tree which is often planted along streets indowntown and residential areas.

Cultivars include: ‘Village Green’ also resemblesthe shape of the American Elm and is more winterhardy than ‘Green Vase’, and may have a straightertrunk.

Diseases

Normally disease-free as it resists Dutch Elmdisease and Elm leaf beetle.

Zelkova is subject to canker diseases particularly ifthe trunk is repeatedly wounded. Avoid wounding andmaintain tree health.