Ulmus americana var. floridana: Florida Elm

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ENH-807 Ulmus americana var. floridana: Florida Elm 1 Edward F. Gilman and Dennis G. Watson 2 1. This document is ENH-807, one of a series of the Environmental Horticulture Department, UF/IFAS Extension. Original publication date November 1993. Revised December 2006. Reviewed February 2014. Visit the EDIS website at http://edis.ifas.ufl.edu. 2. Edward F. Gilman, professor, Environmental Horticulture Department; and Dennis G. Watson, former associate professor, Agricultural Engineering Department, UF/IFAS Extension, Gainesville, FL 32611. The Institute of Food and Agricultural Sciences (IFAS) is an Equal Opportunity Institution authorized to provide research, educational information and other services only to individuals and institutions that function with non-discrimination with respect to race, creed, color, religion, age, disability, sex, sexual orientation, marital status, national origin, political opinions or affiliations. For more information on obtaining other UF/IFAS Extension publications, contact your county’s UF/IFAS Extension office. U.S. Department of Agriculture, UF/IFAS Extension Service, University of Florida, IFAS, Florida A & M University Cooperative Extension Program, and Boards of County Commissioners Cooperating. Nick T. Place, dean for UF/IFAS Extension. Introduction is native North American tree grows quickly when young, forming a broad or upright, vase-shaped silhouette, 60 to 80 feet high and wide. e six-inch-long, deciduous leaves are dark green throughout the year, fading to yellow before dropping in fall. In early spring, before the new leaves unfold, the rather inconspicuous, small, green flowers appear on pendulous stalks. ese blooms are followed by green, wafer-like seedpods which mature soon aſter flowering is finished and the seeds are quite popular with both birds and wildlife. American elm must be at least 15-years-old before it will bear seed. e copious amount of seeds can create a mess on hard surfaces for a period of time. Trees have an extensive but shallow root system. General Information Scientific name: Ulmus americana var. floridana Pronunciation: UL-mus uh-mair-ih-KAY-nuh variety flor-ih-DAY-nuh Common name(s): Florida elm Family: Ulmaceae USDA hardiness zones: 8A through 9B (Fig. 2) Origin: native to North America Invasive potential: little invasive potential Uses: sidewalk cutout (tree pit); parking lot island > 200 sq ſt; reclamation; street without sidewalk; tree lawn > 6 ſt wide; shade; urban tolerant; highway median Availability: somewhat available, may have to go out of the region to find the tree Description Height: 60 to 80 feet Spread: 50 to 60 feet Crown uniformity: symmetrical Crown shape: vase, upright/erect Crown density: moderate Growth rate: fast Texture: medium Figure 1. Young Ulmus americana var. floridana: Florida elm Credits: Ed Gilman, UF/IFAS

Transcript of Ulmus americana var. floridana: Florida Elm

ENH-807

Ulmus americana var. floridana: Florida Elm1

Edward F. Gilman and Dennis G. Watson2

1. This document is ENH-807, one of a series of the Environmental Horticulture Department, UF/IFAS Extension. Original publication date November 1993. Revised December 2006. Reviewed February 2014. Visit the EDIS website at http://edis.ifas.ufl.edu.

2. Edward F. Gilman, professor, Environmental Horticulture Department; and Dennis G. Watson, former associate professor, Agricultural Engineering Department, UF/IFAS Extension, Gainesville, FL 32611.

The Institute of Food and Agricultural Sciences (IFAS) is an Equal Opportunity Institution authorized to provide research, educational information and other services only to individuals and institutions that function with non-discrimination with respect to race, creed, color, religion, age, disability, sex, sexual orientation, marital status, national origin, political opinions or affiliations. For more information on obtaining other UF/IFAS Extension publications, contact your county’s UF/IFAS Extension office.

U.S. Department of Agriculture, UF/IFAS Extension Service, University of Florida, IFAS, Florida A & M University Cooperative Extension Program, and Boards of County Commissioners Cooperating. Nick T. Place, dean for UF/IFAS Extension.

IntroductionThis native North American tree grows quickly when young, forming a broad or upright, vase-shaped silhouette, 60 to 80 feet high and wide. The six-inch-long, deciduous leaves are dark green throughout the year, fading to yellow before dropping in fall. In early spring, before the new leaves unfold, the rather inconspicuous, small, green flowers appear on pendulous stalks. These blooms are followed by green, wafer-like seedpods which mature soon after flowering is finished and the seeds are quite popular with both birds and wildlife. American elm must be at least 15-years-old before it will bear seed. The copious amount of seeds can create a mess on hard surfaces for a period of time. Trees have an extensive but shallow root system.

General InformationScientific name: Ulmus americana var. floridanaPronunciation: UL-mus uh-mair-ih-KAY-nuh variety flor-ih-DAY-nuhCommon name(s): Florida elmFamily: UlmaceaeUSDA hardiness zones: 8A through 9B (Fig. 2)Origin: native to North AmericaInvasive potential: little invasive potentialUses: sidewalk cutout (tree pit); parking lot island > 200 sq ft; reclamation; street without sidewalk; tree lawn > 6 ft wide; shade; urban tolerant; highway medianAvailability: somewhat available, may have to go out of the region to find the tree

DescriptionHeight: 60 to 80 feetSpread: 50 to 60 feetCrown uniformity: symmetricalCrown shape: vase, upright/erectCrown density: moderateGrowth rate: fastTexture: medium

Figure 1. Young Ulmus americana var. floridana: Florida elmCredits: Ed Gilman, UF/IFAS

2Ulmus americana var. floridana: Florida Elm

FoliageLeaf arrangement: alternate (Fig. 3)Leaf type: simpleLeaf margin: double serrateLeaf shape: oblong, ovateLeaf venation: pinnateLeaf type and persistence: deciduousLeaf blade length: 2 to 4 inches, 4 to 8 inchesLeaf color: greenFall color: yellowFall characteristic: not showy

FlowerFlower color: greenFlower characteristics: not showy

FruitFruit shape: roundFruit length: less than .5 inch, .5 to 1 inchFruit covering: dry or hardFruit color: greenFruit characteristics: attracts birds; not showy; fruit/leaves a litter problem

Trunk and BranchesTrunk/bark/branches: branches don’t droop; not showy; typically one trunk; thornsPruning requirement: needed for strong structure

Breakage: susceptible to breakageCurrent year twig color: brownCurrent year twig thickness: thinWood specific gravity: unknown

CultureLight requirement: full sun, partial sun, or partial shadeSoil tolerances: clay; sand; loam; alkaline; acidic; extended flooding; well-drainedDrought tolerance: moderateAerosol salt tolerance: moderate

OtherRoots: not a problemWinter interest: noOutstanding tree: noOzone sensitivity: unknownVerticillium wilt susceptibility: susceptiblePest resistance: resistant to pests/diseases

Use and ManagementOnce a very popular and long-lived shade and street tree, American elm suffered, and is currently suffering, a dramatic decline in most areas in the north with the introduction of Dutch elm disease, a fungus spread by a bark beetle. The wood of American elm is very hard and was a valuable timber tree used for lumber, furniture and veneer. The Indians once made canoes out of American elm trunks, and early settlers would steam the wood so it could be bent to make barrels and wheel hoops. It was also used for the rockers on rocking chairs. Today, the wood that can be found is used mainly for making furniture.

American elm should be grown in full sun on well-drained, rich soil. If you plant American elm, plan on implementing a monitoring program to watch for symptoms of Dutch elm disease. It is vital to the health of existing trees that a program be in place to administer special care to these disease-sensitive trees.

Propagation is by seed or cuttings. Young plants transplant easily.

PestsMany pests may infest elm, including bark beetles, elm borer, gypsy moth, mites, and scales.

DiseasesMany diseases may infect elm, including Dutch elm disease, phloem necrosis, leaf spot diseases, and cankers.

Figure 2. Range

Figure 3. Foliage