# Sweet Azalea (Rhododendron arborescens) > Very fragrant white flowers with red stamens in late spring and early summer, among the last wild azaleas to bloom. Also called smooth azalea, tree azalea, Azalea arborescens. Category: Native Shrubs. Grown from seed by Blue Whale Trees. Web version: https://bluewhaletrees.com/plants/sweet-azalea/ ![Sweet azalea (Rhododendron arborescens) white flowers with long red stamens among glossy leaves](https://bluewhaletrees.com/img/plants/sweet-azalea-h1610-800.jpg) *Photo: Cassidyrg, CC BY-SA 4.0 ยท [Wikimedia Commons](https://commons.wikimedia.org/wiki/File%3ARhododendron_aborescens.jpg)* ## Facts - Type: Shrub - Mature height: 8 to 20 ft - USDA hardiness zones: 4 to 8 - Grows wild in: The Appalachians, stream banks, rocky ground, swamps and wet flats - Native range: 12 states, north to New York, south to Georgia and west to Mississippi (Alabama, Georgia, Kentucky, Maryland, Mississippi, New York, North Carolina, Pennsylvania, South Carolina, Tennessee, Virginia and West Virginia) - Sun: Part, Full - Soil moisture: Average, Wet - Growth rate: Fast - Traits: Showy flowers, Wildlife value, Fall color - Sold as: Saplings, Seed Heights and zones are typical ranges for the species in cultivation; local conditions and seed source shift them. ## Availability Not yet priced online. Ask at captain@bluewhaletrees.com or leave an email on the web page to be told when it is listed. ## Notes Sweet azalea is the tall white azalea of the Appalachians. Its smooth, glossy leaves lack the hairs of most wild azaleas, and they smell of mown grass as they dry. The flowers open after the leaves, and their scent has been likened to cinnamon. It is among the hardiest native white azaleas. John Bartram found it, and it reached British gardens in 1818. Set it near a patio or along a woodland path, where its scent can be enjoyed up close. ## Size, growth and what to expect Sweet azalea grows fast for a native azalea. Our growth estimator treats it as fast, about 2.75 feet a year, slowing as it nears full size. It usually grows 8 to 12 feet tall and as wide, sometimes 20 feet tall. Clusters of 3 to 7 white or pale pink flowers open from May to July. Each is up to 2 inches across, with a red style and long red stamens. The egg-shaped capsules, about 3/4 inch long, follow from July to October. The leaves turn red to purple in fall. It grows wild in the Appalachians from Pennsylvania and Kentucky south to Georgia and Alabama. Its home is stream banks, rocky streamsides, heath balds, swampy woods and bogs, from about 300 to 4,900 feet. ## How to grow Sweet Azalea Sweet azalea does best in part shade or dappled light, in moist, acid, sandy or loamy soil that drains well. It takes ground that is wet for short spells and suits a rain garden, but the roots must not stand in water. Full sun can scorch the leaves, and it does poorly where summers are hot. Set plants 8 feet apart and keep them 6 feet from a wall. At its size it can go within 15 feet of overhead wires. Saplings ship potted. Plant dormant plants in early spring or fall, in a hole three times as wide as the root ball and no deeper. Set the top of the ball a little above grade, and put the native soil back in. On heavy clay, plant on a raised bed or choose another spot. Mulch with wood chips, bark or pine needles, kept off the stems. The seed is dust-fine and needs light, with no chilling. Sow it in winter on the surface of damp milled sphagnum, uncovered, at room temperature under lights and a clear cover. Seedlings come up in one to three weeks. Water weekly through the first two summers, since it is sensitive to drought and the shallow roots must never dry out. Never hoe or dig over them. Rabbits leave it alone, but deer damage it often, so cage it where deer are common. Prune, if at all, right after bloom, since next year's flower buds form by mid to late summer. Each flower carries both male and female parts, and bees, butterflies and hummingbirds visit the flowers. Sources disagree on whether a native azalea sets seed with its own pollen, so plant two seedlings from different parents for seed. It sometimes crosses with swamp azalea, and seed from a plant near other azaleas in bloom may give hybrids. Lace bugs, aphids and mites can mark the leaves, and root rot follows poor drainage. Every part of the plant is poisonous if eaten, and honey from its flowers can be too. ## Sources - [NC State Extension Gardener Plant Toolbox: Rhododendron arborescens](https://plants.ces.ncsu.edu/plants/rhododendron-arborescens/) - [Missouri Botanical Garden Plant Finder: Rhododendron arborescens](https://plantfinder.mobot.org/PlantFinderDetails.aspx?taxonid=279973) - [Lady Bird Johnson Wildflower Center: Rhododendron arborescens](https://www.wildflower.org/plants/result.php?id_plant=RHAR3) - [Flora of North America, vol. 8: Rhododendron arborescens](http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=250065654) - [Trees and Shrubs Online: Rhododendron arborescens](https://www.treesandshrubsonline.org/articles/rhododendron/rhododendron-arborescens/) - [USDA Forest Service, Woody Plant Seed Manual (2008), Rhododendron chapter](https://www.fs.usda.gov/nsl/Wpsm/Rhododendron.pdf) - [NatureServe Explorer: Rhododendron arborescens](https://explorer.natureserve.org/Taxon/ELEMENT_GLOBAL.2.156028/Rhododendron_arborescens) - [Virginia Department of Conservation and Recreation: Natural Heritage Resources of Virginia, Rare Plants, June 2026](https://www.dcr.virginia.gov/natural-heritage/document/plantlist-current.pdf) - [Maryland Natural Heritage Program: List of Rare, Threatened, and Endangered Plants of Maryland, March 2021](https://dnr.maryland.gov/wildlife/Documents/rte_Plant_List.pdf) - [Alabama Cooperative Extension System: Native Azaleas, Chip East, April 15, 2020](https://www.aces.edu/blog/topics/landscaping/native-azaleas/) - [UConn Plant Database: Rhododendron arborescens](https://plantdatabase.uconn.edu/detail.php?pid=410) ## Read before planting - [Ten planting mistakes that quietly kill trees](https://bluewhaletrees.com/articles/ten-planting-mistakes/index.html.md) - [Transplanting young trees: timing, water and protection](https://bluewhaletrees.com/articles/transplanting-young-trees/index.html.md) - [Protecting young trees from voles, rabbits, deer and squirrels](https://bluewhaletrees.com/articles/protecting-trees-from-animals/index.html.md) - [The habitat around a tree is part of the tree](https://bluewhaletrees.com/articles/habitat-around-a-tree/index.html.md) - [Invasive vines and shrubs are what is killing your woods](https://bluewhaletrees.com/articles/invasive-vines-and-shrubs/index.html.md) - [Native trees and shrubs for birds: caterpillars, fruit, mast, nests and winter cover, month by month](https://bluewhaletrees.com/articles/native-trees-for-birds/index.html.md) ## Related - [Planting-site check](https://bluewhaletrees.com/tools/site-check/index.html.md): for a thrive, struggle or fail verdict on Sweet Azalea, add ?species=sweet-azalea with zone (2 to 10), sun (full, part, shade) and moisture (dry, average, wet) to that address, for example ?species=sweet-azalea&zone=4&sun=part&moisture=average. - [Companion species for Sweet Azalea](https://bluewhaletrees.com/tools/companions/index.html.md?species=sweet-azalea): the natives that share its ground and the plants that pair with it in a yard. - [Growth estimator](https://bluewhaletrees.com/tools/growth/index.html.md): how the height and trunk projections are made; the estimate itself runs in the browser at https://bluewhaletrees.com/tools/growth/#species=sweet-azalea - [Seed sowing planner](https://bluewhaletrees.com/tools/sowing/index.html.md): how Sweet Azalea is sown, in the chart for every species (treatment, cold days, depth, timing); the dated plan runs in the browser at https://bluewhaletrees.com/tools/sowing/#species=sweet-azalea - [Pollination planner](https://bluewhaletrees.com/tools/pollination/index.html.md): what Sweet Azalea needs for a crop and how many to plant, in the table for every species; the planner runs in the browser at https://bluewhaletrees.com/tools/pollination/#plants=sweet-azalea:2 - [Bloom and fruit calendar](https://bluewhaletrees.com/tools/calendar/index.html.md): the months Sweet Azalea flowers and fruits, in the grid for every species.