Students for Stewardship The Cork Board
← Back to the library

Lily of the Valley Tree

Oxydendrum arboreum (ok-see-DEN-drum ar-BOR-ee-um)

Family: Ericaceae Native Understory (15-40 ft)

Sourwood is a deciduous, small to medium tree in the blueberry family (Ericaceae). It is native to the eastern and southern United States, from Pennsylvania to northern Florida and west to Ohio and Louisiana. It can be found throughout North Carolina, although more rarely in the low, alluvial plain. It grows 20 to 30 feet tall and 10 to 15 feet wide. This plant prefers acidic, peaty, moist, well-drained soils in full sun to partial shade. It is tolerant of shade and dry soils and moderately tolerant of salt. It is intolerant of pollution and urban areas. A very ornamental plant, it will flower in 4 to 5 years after planting from seed. This plant does not like to be transplanted so only do so with young plants. The bark is red-brown with deep vertical furrows that separate flat, pointed ridges. In mid-summer, fragrant, white, urn-shaped flowers mature on panicles. Fall foliage is red to reddish-purple. Sourwood makes an excellent understory tree or planted in small groups in a woodland garden. It also serves well as a shade or flowering specimen in a native, pollinator, butterfly, or children’s garden. Insects, Diseases, or Other Plant Problems: Fall webworm is an occasional problem. Leaf spot and twig blight infrequently occur.

Source: NC State Extension Gardener Plant Toolbox ↗ NC State Extension Gardener Plant Toolbox, 75 attributes.

How it fits the guild

Guild layer 2 - Understory (15-40 ft) Optimal soil pH Acid (<6.0)
See companions & conflicts ↓

Companions & Conflicts

Curated pairwise relationships between this plant and others in the library — who feeds whom, who competes, who confuses the pests. Green reads as a good pairing, red as one to avoid.

No curated interactions recorded for this species yet.

Also noted by NC State

Related species the NC State Plant Toolbox flags for this plant — look-alikes to tell apart, and plants that play a similar role in a planting. Ones we carry in the library are linked.

Often confused with Agarista populifolia Diospyros virginiana Leucothoe fontanesiana Pieris japonica Prunus laurocerasus 'Otto Luyken'

Full plant profile

Growing Conditions
Plant type
Native Plant; Perennial; Tree
Life cycle
Perennial; Woody
USDA zones
5a, 5b, 6a, 6b, 7a, 7b, 8a, 8b, 9a, 9b
Light
Dappled Sunlight (Shade through upper canopy all day) | Deep shade (Less than 2 hours to no direct sunlight) | Full sun (6 or more hours of direct sunlight a day) | Partial Shade (Direct sunlight only part of the day, 2-6 hours)
Soil texture
High Organic Matter; Loam (Silt)
Soil pH
Acid (<6.0)
Soil drainage
Good Drainage | Moist | Occasionally Dry
Available space
12-24 feet
NC region
Coastal; Mountains; Piedmont
Mature size
Height: 20 ft. 0 in. - 30 ft. 0 in. | Width: 10 ft. 0 in. - 15 ft. 0 in.
Growth rate
Slow
Maintenance
Low
Canopy layer
2 - Understory (15-40 ft)
Form & Appearance
Habit / form
Oval; Pyramidal; Rounded
Texture
Medium
Foliage
Deciduous
Leaf color
Gold/Yellow; Green; Purple/Lavender
Leaf type
Simple
Leaf arrangement
Alternate
Leaf shape
Elliptical; Lanceolate; Oblong
Leaf margin
Entire; Serrate
Leaf feel
Glossy; Rough
Leaf value
Showy
Leaf size
> 6 inches long, 1-3 inches wide
Hairs present
No
Leaf detail
Alternate, simple, finely-toothed, glossy green leaves (3 to 6 inches long to 1 to 3 inches wide) entire to serrate margin shiny and glossy, reminiscent of a peach or laurel leaf. Young leaves have fine marginal hairs. They are elliptic to oval or oblong-lanceolate, acute, minutely serrulate, accuminate, and broadly cuneate. They have a sour taste, hence the common name. They produce consistently excellent fall color, typically turning crimson red, but sometimes yellow and purple.
Fall color
Gold/Yellow; Purple/Lavender; Red/Burgundy
Flower color
Cream/Tan; White
Flower value
Fragrant; Showy
Flower form
Panicle
Flower shape
Bell
Flower size
< 1 inch
Flower detail
Waxy, lily-of-the-valley-like, white bell-shaped flowers that bloom on slender, second on axis, drooping, one-sided slender terminal panicles (4 to 8 inches long) from June to July. Flowers have a 5 lobed calyx and an urceolate corolla that is finely downy, white, 5-lobed, and minute. The flowers themselves have a slight fragrance and are 1/4" long. The panicles persist after flowers drop and resemble long fingers.
Bloom time
Summer
Fruit color
Brown/Copper
Fruit type
Capsule
Fruit value
Showy
Fruit size
< 1 inch long
Fruit detail
Five-valved brownish dehiscent dry capsules , 1/3 to 1/2 inch long, that ripen to silver-gray in September and October. Capsules contrast well with the red fall color and provide continuing ornamental interest after leaf drop into winter.
Bark color
Dark Gray; Light Gray
Bark detail
Dark, thin, gray bark on mature trees is has light gray fissures, ridged and scaly, becomes blocky with age. On first-year shoots, the bark is often bright red.
Stem color
Brown/Copper
Stem detail
Stems are slender, glabrous or sparingly pubescent, and do not go dormant in the winter. Twigs are seemingly terminated by a leaf and bud, but bud is axillary and minute stem growth is adjacent. Buds are lateral or axillary, small (less than an inch in size), are conical-globose, and sessile. Branches are narrow, elongate, decurved then swept upright, and persist after leaves.
Wildlife & Ecology
Native status
Native
Origin
Eastern and southern United States
Distribution
Pennsylvania to Florida, west to Louisiana and Ohio.
Wildlife value
The flowers are attractive to butterflies and other insects. Natural hollows in these trees are refuge for climbing reptiles and amphibians, bats and other small wildlife. Old fall webworm tents attract invertebrates that birds often eat during late fall and winter. Flowers are quite attractive to bees and the honey is highly sought after.
Attracts
Bees; Butterflies; Pollinators; Small Mammals; Songbirds
Play value
Attractive Flowers; Attracts Pollinators; Buffer; Wildlife Food Source
Food & Medicine
Edible parts
Leaves
Harvest time
Fall
Fruit type
Capsule

Edibility

Leaves contain oxalic acid and acidic to taste. A tea made from the leaves has been used in the treatment of asthma, diarrhoea, indigestion.

Uses (ethnobotany)

Bees produce a rich and popular honey from the nectar. Wood is heavy, hard, and closegrained, but is seldom used as a commercial wood.

Landscape Use
Landscape location
Coastal; Recreational Play Area; Woodland
Landscape theme
Butterfly Garden; Children's Garden; Cottage Garden; Native Garden; Pollinator Garden; Rain Garden; Shade Garden
Design feature
Flowering Tree; Shade Tree; Small groups; Specimen; Understory Tree
Garden tags
#deciduous #salt tolerant #amphibians #reptiles #deer resistant #fire low flammability #flowering tree #understory tree #showy fruits #specimen #fall interest #winter interest #year-round interest #pollinator plant #children's garden #NC native #fantz #bird friendly #butterfly friendly #food source hard mast fruit #Coastal FACU #food source nectar #food source pollen #mammals #piedmont mountains UPL #food source fall #fall color red #showy flowers #Audubon #honey #nectar plant early summer #nectar plant mid-summer #bee friendly #pest resistant #playground plant #landscape plant sleuths course #NC Native Pollinator Plant #wildlife friendly #larval host plant #cpp #woodland #fragrant flowers #rain garden #HS304 #small groups #bat friendly
Problems & Resistance
Insect problems
Fall Webworm
Resistant to
Deer; Dry Soil; Fire; Salt
Particularly resistant to
Resistant to fire. Moderately resistant to deer damage. Heat tolerant.
Propagation
Seed; Stem Cutting
Fire risk
low flammability

Planted at Hunnicutt

Nobody’s planted this one yet.