Azaleas ( ) are flowering
shrub
A shrub or bush is a small to medium-sized perennial woody plant. Unlike herbaceous plants, shrubs have persistent woody stems above the ground. Shrubs can be either deciduous or evergreen. They are distinguished from trees by their multiple ...
s in the genus ''
Rhododendron
''Rhododendron'' (; : ''rhododendra'') is a very large genus of about 1,024 species of woody plants in the Ericaceae, heath family (Ericaceae). They can be either evergreen or deciduous. Most species are native to eastern Asia and the Himalayan ...
'', particularly the former sections ''
Tsutsusi'' (evergreen) and ''
Pentanthera'' (deciduous). Azaleas bloom in the spring (April and May in the temperate Northern Hemisphere, and October and November in the Southern Hemisphere), their flowers often lasting several weeks. Shade tolerant, they prefer living near or under trees. They are part of the family
Ericaceae
The Ericaceae () are a Family (biology), family of flowering plants, commonly known as the heath or heather family, found most commonly in acidic and infertile growing conditions. The family is large, with about 4,250 known species spread acros ...
.
Cultivation
Plant enthusiasts have selectively bred azaleas for hundreds of years. This human selection has produced thousands of different
cultivar
A cultivar is a kind of Horticulture, cultivated plant that people have selected for desired phenotypic trait, traits and which retains those traits when Plant propagation, propagated. Methods used to propagate cultivars include division, root a ...
s which are propagated by cuttings. Azalea
seed
In botany, a seed is a plant structure containing an embryo and stored nutrients in a protective coat called a ''testa''. More generally, the term "seed" means anything that can be Sowing, sown, which may include seed and husk or tuber. Seeds ...
s can also be collected and
germinated.
Azaleas are generally slow-growing and do best in well-drained acidic soil (4.5–6.0 pH).
Fertilizer
A fertilizer or fertiliser is any material of natural or synthetic origin that is applied to soil or to plant tissues to supply plant nutrients. Fertilizers may be distinct from liming materials or other non-nutrient soil amendments. Man ...
needs are low. Some species need regular
pruning.
Azaleas are native to several continents including Asia, Europe and North America. They are planted abundantly as ornamentals in the southeastern US, southern Asia, and parts of southwest Europe.

According to azalea historian Fred Galle, in the United States, ''Azalea indica'' (in this case, the group of plants called Southern indicas) was first introduced to the outdoor landscape in the 1830s at the rice plantation
Magnolia-on-the-Ashley in
Charleston, South Carolina
Charleston is the List of municipalities in South Carolina, most populous city in the U.S. state of South Carolina. The city lies just south of the geographical midpoint of South Carolina's coastline on Charleston Harbor, an inlet of the Atla ...
. From Philadelphia, where they were grown only in
greenhouse
A greenhouse is a structure that is designed to regulate the temperature and humidity of the environment inside. There are different types of greenhouses, but they all have large areas covered with transparent materials that let sunlight pass an ...
s, John Grimke Drayton (Magnolia's owner) imported the plants for use in his estate garden. With encouragement from
Charles Sprague Sargent
Charles Sprague Sargent (April 24, 1841March 22, 1927) was an American botanist. He was appointed in 1872 as the first director of Harvard University's Arnold Arboretum in Boston, Massachusetts, and held the post until his death. He published se ...
from Harvard's Arnold Arboretum, Magnolia Gardens was opened to the public in 1871, following the American Civil War. Magnolia is one of the oldest public gardens in America. Since the late 19th century, in late March and early April, thousands visit to see the azaleas bloom in their full glory.
Classification
North American azaleas
Disease
Azalea leafy gall can be particularly destructive to azalea leaves during the early spring. Hand picking infected leaves is the recommended method of control.
They can also be subject to ''
Phytophthora
''Phytophthora'' (from Greek (''phytón''), "plant" and (), "destruction"; "the plant-destroyer") is a genus of plant-damaging oomycetes (water molds), whose member species cause economic losses on crops worldwide, as well as environmental dam ...
'' root rot in moist, hot conditions.
Azaleas share the economically important disease ''
Phytophthora cinnamomi'' with more than 3000 other plants.
Pests
Azaleas share the Azalea lace bug (''
Stephanitis pyrioides'') with many other heath species.
Shrewsbury & Raupp 2000 find azaleas can be protected from them by
companion planting
Companion planting in gardening and agriculture is the planting of different crops in proximity for any of a number of different reasons, including Weed control, weed suppression, pest control, pollination, providing habitat for beneficial ins ...
with an
overstory above them.
Cultural significance and symbolism
In Chinese culture, the azalea is known as "thinking of home bush" (''sixiang shu''), and is immortalized in the poetry of
Du Fu
Du Fu (; 712–770) was a Chinese poet and politician during the Tang dynasty. Together with his elder contemporary and friend Li Bai, Du is often considered one of the greatest Chinese poets of his time. His greatest ambition was to serve ...
.
The azalea is also one of the symbols of the city of
São Paulo
São Paulo (; ; Portuguese for 'Paul the Apostle, Saint Paul') is the capital of the São Paulo (state), state of São Paulo, as well as the List of cities in Brazil by population, most populous city in Brazil, the List of largest cities in the ...
,
Brazil
Brazil, officially the Federative Republic of Brazil, is the largest country in South America. It is the world's List of countries and dependencies by area, fifth-largest country by area and the List of countries and dependencies by population ...
.
Azaleas and rhododendrons were once so infamous for their toxicity that to receive a bouquet of their flowers in a black vase was a well-known death threat.
Toxicity
In addition to being renowned for its beauty, the azalea is also highly toxic—it contains
andromedotoxins in both its leaves and nectar, including honey from the nectar. Bees are deliberately fed on Azalea/
Rhododendron
''Rhododendron'' (; : ''rhododendra'') is a very large genus of about 1,024 species of woody plants in the Ericaceae, heath family (Ericaceae). They can be either evergreen or deciduous. Most species are native to eastern Asia and the Himalayan ...
nectar in some parts of Turkey, producing a mind-altering, potentially medicinal, and occasionally lethal honey known as "
mad honey".
Azalea is dangerous to pets, as, if consumed, the toxins within the plant tissue can cause
central nervous system depression
Central nervous system depression (or CNS depression) is a nervous system disorder characterized by a severely impaired physiological state in which patients may exhibit decreased rate of breathing, decreased heart rate, and loss of consciousnes ...
, which in turn can lead to multi-organ failure. Symptoms may include vomiting, diarrhea, seizures, laryngeal edema and heart rhythm disturbances, which can lead to complete cardiac arrest and therefore death. Acute kidney failure may also occur.
Azalea festivals
Japan
Motoyama, Kōchi has a flower festival in which the blooming of Tsutsuji is celebrated.
Tatebayashi, Gunma is famous for its Azalea Hill Park, Tsutsuji-ga-oka.
Nezu Shrine in
Bunkyo, Tokyo, holds a Tsutsuji Matsuri from early April until early May.
Higashi Village has hosted an azalea festival each year since 1976. The village's 50,000 azalea plants draw an estimated 60,000 to 80,000 visitors each year.
Korea
Sobaeksan, one of the 12 well-known
Sobaek Mountains, lying on the border between
Chungbuk Province and
Gyeongbuk has a royal azalea (''
Rhododendron schlippenbachii'') festival held on May every year. Sobaeksan has an azalea colony dotted around Biro mountaintop, Gukmang and Yonwha early in May. When royal azaleas have turned pink in the end of May, it looks like Sobaeksan wears a pink
Jeogori (Korean traditional jacket).
Hong Kong
The Ma On Shan Azalea Festival is held in
Ma On Shan, where six native species (''
Rhododendron championae'', ''
Rhododendron farrerae'', ''
Rhododendron hongkongense'', ''
Rhododendron moulmainense'', ''
Rhododendron simiarum'' and ''
Rhododendron simsii'' ) are found in the area. The festival has been held since 2004; it includes activities such as exhibitions, photo contests and carnivals.
United States
Many cities in the United States have festivals in the spring celebrating the blooms of the azalea, including
Summerville, South Carolina
Summerville is a town in the U.S. state of South Carolina situated mostly in Dorchester County, South Carolina, Dorchester County, with small portions in Berkeley County, South Carolina, Berkeley and Charleston County, South Carolina, Charleston ...
;
Hamilton, New Jersey;
Mobile, Alabama
Mobile ( , ) is a city and the county seat of Mobile County, Alabama, United States. The population was 187,041 at the 2020 United States census, 2020 census. After a successful vote to annex areas west of the city limits in July 2023, Mobil ...
;
Jasper, Texas
Jasper is a Administrative divisions of Texas, city in and the county seat of Jasper County, Texas, Jasper County, Texas, United States. Its population was 6,884 at the 2020 United States census, 2020 U.S. Census, down from 7,590 at the 2010 Un ...
;
Tyler, Texas
Tyler, officially the City of Tyler, is a city in and the county seat of Smith County, Texas, United States. As of 2020, the population is 105,995. Tyler was the List of municipalities in Texas, 38th most populous city in Texas (as well as the m ...
;
Norfolk, Virginia
Norfolk ( ) is an independent city (United States), independent city in the U.S. state of Virginia. It had a population of 238,005 at the 2020 United States census, 2020 census, making it the List of cities in Virginia, third-most populous city ...
;
Wilmington, North Carolina
Wilmington is a port city in New Hanover County, North Carolina, United States. With a population of 115,451 as of the 2020 United States census, 2020 census, it is the List of municipalities in North Carolina, eighth-most populous city in the st ...
(
North Carolina Azalea Festival);
Valdosta, Georgia
Valdosta is a city in and the county seat of Lowndes County, Georgia, Lowndes County in the U.S. state of Georgia (U.S. state), Georgia. As the principal city of the Valdosta Metropolitan Statistical Area, Valdosta metropolitan statistical area, ...
;
Palatka, Florida
Palatka () is a city in and the county seat of Putnam County, Florida, Putnam County, Florida, United States. Palatka is the principal city of the Palatka Micropolitan Statistical Area, which is home to 72,893 residents. The Palatka micropolitan ...
(
Florida Azalea Festival);
Pickens, South Carolina;
Muskogee, Oklahoma
Muskogee () is the 13th-largest city in Oklahoma and is the county seat of Muskogee County, Oklahoma, Muskogee County. Home to Bacone College, it lies approximately southeast of Tulsa, Oklahoma, Tulsa. The population of the city was 36,878 as of ...
;
Brookings, Oregon
Brookings is a city in Curry County, Oregon, Curry County, Oregon, United States. It was named after John E. Brookings, president of the Brookings Lumber & Box Company, who founded the city in 1908. As of the 2020 United States census, 2020 censu ...
; and
Nixa, Missouri
Nixa is a city in Christian County, Missouri, United States. As of the 2020 census, the city's population was 23,257. It is a principal city, and the second largest city in the Springfield, Missouri Metropolitan Area.
History
The area was f ...
.
The Azalea Trail is a designated path, planted with azaleas in private gardens, through
Mobile, Alabama
Mobile ( , ) is a city and the county seat of Mobile County, Alabama, United States. The population was 187,041 at the 2020 United States census, 2020 census. After a successful vote to annex areas west of the city limits in July 2023, Mobil ...
.
The
Azalea Trail Run is an annual road running event held there in late March. Mobile, Alabama is also home to the
Azalea Trail Maids, fifty women chosen to serve as ambassadors of the city while wearing
antebellum
Antebellum, Latin for "before war", may refer to:
United States history
* Antebellum South, the pre-American Civil War period in the Southern US
** Antebellum Georgia
** Antebellum South Carolina
** Antebellum Virginia
* Antebellum architectu ...
dresses, who originally participated in a three-day festival, but now operate throughout the year.
The Azalea Society of America designated Houston, Texas, an "azalea city". The River Oaks Garden Club has conducted the Houston Azalea Trail every spring since 1935.
Valdosta, Georgia is called the Azalea City, as the plant grows in profusion there. The city hosts an annual Azalea Festival in March.
See also
*
List of Award of Garden Merit rhododendrons
*
List of plants poisonous to equines
References
External links
*
American Rhododendron Society: What is an Azalea?
{{Authority control
Historically recognized angiosperm genera
Plants used in bonsai
Rhododendron
Shrubs
Symbols of Georgia (U.S. state)