ENH-759

Stewartia koreana: Korean Stewartia1

Edward F. Gilman and Dennis G. Watson2

1. This document is ENH-759, 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.

IntroductionCapable of reaching 50 feet in height, Korean stewartia is most often seen at 20 to 30 feet, its short, interwoven branchlets forming a dense, pyramidal canopy which casts deep shade below this deciduous tree. The one to four-inch-long by one to three-inch-wide dark green leaves often turn to lovely shades of orange, red, or purple in the fall but this is not a reliable occurrence. Over a several week period in June to July, Korean stewartia is decorated with lovely, pure white, yellow-centered blossoms, three-inches-across and flattened, appearing much like a single camellia flower. Each flower is open for about 24 hours and they attract bees. Most other trees have finished flowering by the time these flowers emerge. The bark of Korean Stewartia is probably the most outstanding characteristic, with orange/brown patches showing through the flaking, grey bark.

General InformationScientific name: Stewartia koreanaPronunciation: stoo-AR-tee-uh kor-ee-AY-nuhCommon name(s): Korean stewartiaFamily: TheaceaeUSDA hardiness zones: 5B through 7B (Fig. 2)Origin: not native to North AmericaInvasive potential: little invasive potentialUses: specimen; deck or patio; street without sidewalk; container or planter; espalier; parking lot island 100-200 sq ft; parking lot island > 200 sq ft; sidewalk cutout (tree pit);

tree lawn 3-4 feet wide; tree lawn 4-6 feet wide; tree lawn > 6 ft wide; highway medianAvailability: not native to North America

DescriptionHeight: 20 to 30 feetSpread: 15 to 25 feetCrown uniformity: symmetricalCrown shape: upright/erect, pyramidalCrown density: denseGrowth rate: slowTexture: medium

Figure 1. Young Stewartia koreana: Korean stewartia

2Stewartia koreana: Korean Stewartia

FoliageLeaf arrangement: alternate (Fig. 3)Leaf type: simpleLeaf margin: serrateLeaf shape: elliptic (oval)Leaf venation: pinnate, brachidodromeLeaf type and persistence: deciduousLeaf blade length: less than 2 inches, 2 to 4 inchesLeaf color: greenFall color: orange, red, purpleFall characteristic: showy

FlowerFlower color: white/cream/grayFlower characteristics: showy

FruitFruit shape: oval, roundFruit length: 1 to 3 inchesFruit covering: dry or hardFruit color: redFruit characteristics: attracts birds; not showy; fruit/leaves not a litter problem

Trunk and BranchesTrunk/bark/branches: branches don’t droop; very showy; typically multi-trunked; thornsPruning requirement: little requiredBreakage: resistantCurrent year twig color: gray, greenCurrent year twig thickness: thin, mediumWood specific gravity: unknown

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

OtherRoots: not a problemWinter interest: noOutstanding tree: yesOzone sensitivity: unknownVerticillium wilt susceptibility: unknownPest resistance: free of serious pests and diseases

Use and ManagementThis tree can be used in much the same way as Japanese stewartia. It is unsurpassed as a specimen, but can also be included in a shrub border, planted near a patio or deck to show off the wonderful bark, or used as a multi-trunked street tree planted on 20-foot centers. Set it off as a speci-men by placing it in a bed of low, evergreen ground cover.

Korean stewartia should be grown in full sun but reportedly looks best where it can receive some shade during the hottest part of the day. However, there are fine-looking specimens growing in poor clay soil in USDA hardiness zone 7b with no irrigation which are located in full-day sun. The soil should preferably be moist, acid, and supplemented with organic matter. Pruning is seldom required as growth rate is slow and branches normally keep in bounds, staying close to the tight canopy.

Propagation is by seed (with difficulty) or by cuttings.

Pests and DiseasesNo pests or diseases of major concern.

Figure 2. Range

Figure 3. Foliage