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Cobb County Extension Service

Fact Sheet on

Rachel Swinford
Horticulture Program Assistant

email: uge1067@arches.uga.edu

Gardenias

Gardenia jasminoides

Cape Jasmine, Gardenia

Family: Rubiaceae

Native: China, Taiwan, Japan

Hardiness: Zone 7B to 10 – Hardy to 10ºF. May die back to the ground and regenerate at 0ºF.

Growth Rate: Moderate

Uses: Patio, walkways (to enjoy fragrance), container, specimen, groundcover, corsage, espalier, bonsai

The gardenia is highly valued for its incredible fragrance, long-blooming flowers and handsome foliage. There are over 250 species, but, most are not cold hardy enough for Cobb County. The gardenia is named for Alexander Garden (1730-91), a Scottish physician and botanist who lived in Charleston, South Carolina.

Description:

Flower:

Elegant single or multi-petaled, waxy white aging to yellow. Extraordinary fragrance on long-blooming flowers growing on new growth from spring through summer. 2-4 inches diameter.

Leaves:

Evergreen. Thick, leathery. Glossy dark green, lighter green below. 2-4 inches long depending on variety, one-half as wide. Older leaves turn bright yellow once or twice a year before dropping off.

Stems:

Green, turning brown.

Fruit:

Orange, fleshy, oval, 1 to 1 1/2 inch long berry in fall.

Roots:

Close to the surface. Protect with 3 to 4 inches of mulch throughout the summer. Do not cultivate.

Habit:

Dense, rounded 4 to 6 feet high and equally wide.

Planting & Maintenance:

Propagation:

Softwood cuttings June, July, August are best. Semi hardwood cuttings in fall.

Planting:

Plant in spring when the soil is warm. Transplant in spring.

Site:

Acid, moist, well-drained soil. pH 5.0-6.5.

Protect from winter winds and cold – eastern or northern exposure is best. Full sun to partial shade. Morning sun and afternoon shade is best. Too much shade will cause leggy growth and fewer flowers. Too much sun will cause the blooms to brown faster.

Water:

Moist, well-drained soil.

Weeds:

Mulch, do not cultivate – roots are shallow.

Temperature:

Hardy to 10ºF. At 0ºF may die back to the ground and regenerate.

Fertilization:

Acid plant food, fish emulsion, blood meal, bone meal or azalea and camellia food in early spring and midsummer according to a soil test.

Pruning:

Little or none. Remove straggly branches, faded flowers. Thin to reshape. Rejuvenate by cutting stems to 12 inches above the ground in early spring. Tip prune after flowering. Pruning after September decreases next year’s blooms.

Cultivars:

August Beauty

Large, double, white flowers, heavy-flowering May through October. Small, narrow leaves. 4 to 6 feet high.

Candle Light

Double, fragrant, white flowers, dark green foliage, medium-sized shrub.

Daisy

Flat-faced, single, fragrant, compact, more cold hardy than double forms.

Kleim’s Hardy

Single, fragrant, ivory, 2 inch flowers in summer, more cold hardy, 3 feet high.

Michael

Cold hardy, resistant to white fly.

Mystery

Huge, 4-5 inch, double, white flowers in summer. 4 to 8 feet, upright shrub. May need pruning to keep neat.

Radicans

Small-leaved, 1 to 2 inch, double flowers. 2 to 3 feet high, spreads to 4 feet. Less cold hardy than other choices. Often used for bonsai.

Problems:

Whiteflies

Common pest. Suck sap from leaves and excrete "honeydew" turning leaves black with sooty mold.

Aphids, scale, mealybugs, mites, nematodes

Requires regular inspection to control. Can lead to sooty mold.

Stem canker

Usually enters plant through wounds. No treatment available. Destroy plants to prevent spread.

Yellowing leaves

Chlorosis due to deficiency of micronutrients (usually iron). Fertilizing the soil according to a soil test usually solves this problem.

References: The American Horticultural Society A-Z Encyclopedia of Garden Plants, Christopher Brickell, Judith D. Zuk, 1997

Manual of Woody Landscape Plants, Michael A. Dirr, 1998

Landscape Plants of the Southeast, R. Gordon Halfacre, Anne R. Shawcroft, Fifth Edition 1989

University of Florida Cooperative Extension Service Website http://edis.ifas.ufl.edu

FACT SHEET INDEX - Index of fact sheets on pests, diseases and plants of particular importance to Cobb County.

The University of Georgia and Ft. Valley State University, the U.S. Department of Agriculture and counties of the state cooperating. The Cooperative Extension Service offers educational programs, assistance and materials to all people without regard to race, color, national origin, age, sex or disability.

Description:	Flower:	Elegant single or multi-petaled, waxy white aging to yellow. Extraordinary fragrance on long-blooming flowers growing on new growth from spring through summer. 2-4 inches diameter.
	Leaves:	Evergreen. Thick, leathery. Glossy dark green, lighter green below. 2-4 inches long depending on variety, one-half as wide. Older leaves turn bright yellow once or twice a year before dropping off.
	Stems:	Green, turning brown.
	Fruit:	Orange, fleshy, oval, 1 to 1 1/2 inch long berry in fall.
	Roots:	Close to the surface. Protect with 3 to 4 inches of mulch throughout the summer. Do not cultivate.
	Habit:	Dense, rounded 4 to 6 feet high and equally wide.
Planting & Maintenance:	Propagation:	Softwood cuttings June, July, August are best. Semi hardwood cuttings in fall.
	Planting:	Plant in spring when the soil is warm. Transplant in spring.
	Site:	Acid, moist, well-drained soil. pH 5.0-6.5. Protect from winter winds and cold – eastern or northern exposure is best. Full sun to partial shade. Morning sun and afternoon shade is best. Too much shade will cause leggy growth and fewer flowers. Too much sun will cause the blooms to brown faster.
	Water:	Moist, well-drained soil.
	Weeds:	Mulch, do not cultivate – roots are shallow.
	Temperature:	Hardy to 10ºF. At 0ºF may die back to the ground and regenerate.
	Fertilization:	Acid plant food, fish emulsion, blood meal, bone meal or azalea and camellia food in early spring and midsummer according to a soil test.
	Pruning:	Little or none. Remove straggly branches, faded flowers. Thin to reshape. Rejuvenate by cutting stems to 12 inches above the ground in early spring. Tip prune after flowering. Pruning after September decreases next year’s blooms.
Cultivars:	August Beauty	Large, double, white flowers, heavy-flowering May through October. Small, narrow leaves. 4 to 6 feet high.
	Candle Light	Double, fragrant, white flowers, dark green foliage, medium-sized shrub.
	Daisy	Flat-faced, single, fragrant, compact, more cold hardy than double forms.
	Kleim’s Hardy	Single, fragrant, ivory, 2 inch flowers in summer, more cold hardy, 3 feet high.
	Michael	Cold hardy, resistant to white fly.
	Mystery	Huge, 4-5 inch, double, white flowers in summer. 4 to 8 feet, upright shrub. May need pruning to keep neat.
	Radicans	Small-leaved, 1 to 2 inch, double flowers. 2 to 3 feet high, spreads to 4 feet. Less cold hardy than other choices. Often used for bonsai.
Problems:	Whiteflies	Common pest. Suck sap from leaves and excrete "honeydew" turning leaves black with sooty mold.
	Aphids, scale, mealybugs, mites, nematodes	Requires regular inspection to control. Can lead to sooty mold.
	Stem canker	Usually enters plant through wounds. No treatment available. Destroy plants to prevent spread.
	Yellowing leaves	Chlorosis due to deficiency of micronutrients (usually iron). Fertilizing the soil according to a soil test usually solves this problem.