Students for Stewardship The Cork Board
← Back to the library

Large Bluet

Houstonia purpurea (hoos-TOH-nee-uh pur-PUR-ee-ah)

Family: Rubiaceae Native Groundcover (<1 ft)

Mountain bluet is a common native herbaceous perennial native to the eastern United States and is found in the mountains and Piedmont of North Carolina. In its natural habitat, it can be found in many locations, such as on well-drained slopes, along streams and lakes, hardwood floodplains, moist woods, rocky upland forests, rocky bluffs, pastures, and limestone glades. It prefers well-drained, moist to dry, fertile soil in full sun to partial shade or dappled sunlight. Propagation is by seed or division. It forms low mounds and spreads slowly, growing 4 to 12 inches tall and spreading up to 1 foot. It has broad terminal clusters of three or more blooms on branching, hairy stems. The flowers have four lavender-blue to almost white petals that fuse into a deep tube. Usually the central flower opens first. Although this is a short-lived plant, its self-seeding properties allow the plant to appear year after year. It is sometimes confused with Houstonia longifolia , the difference being that the leaves along the stem are wider and rounded at the base and have sepals that are longer when in bloom. It can be grown as a ground cover that can be mowed. To allow it to self-seed, avoid mowing until it has set its seed. It can also be used in a rock garden, pollinator garden and along walkways. Insects, Diseases, and Other Plant Problems: Snails and slugs are common pests of this plant.

Source: NC State Extension Gardener Plant Toolbox ↗ NC State Extension Gardener Plant Toolbox, 62 attributes.

How it fits the guild

Guild layer 5 - Groundcover (<1 ft) Optimal soil pH Acid (<6.0); Neutral (6.0-8.0)
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.

Full plant profile

Growing Conditions
Plant type
Herbaceous Perennial; Native Plant; Wildflower
Life cycle
Perennial
USDA zones
3a, 3b, 4a, 4b, 5a, 5b, 6a, 6b, 7a, 7b, 8a, 8b
Light
Dappled Sunlight (Shade through upper canopy all day) | 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); Sand; Shallow Rocky
Soil pH
Acid (<6.0); Neutral (6.0-8.0)
Soil drainage
Good Drainage | Moist | Occasionally Dry
Available space
12 inches-3 feet
NC region
Mountains; Piedmont
Mature size
Height: 0 ft. 6 in. - 0 ft. 8 in. | Width: 0 ft. 4 in. - 1 ft. 0 in.
Growth rate
Medium
Maintenance
Low
Canopy layer
5 - Groundcover (<1 ft)
Form & Appearance
Habit / form
Clumping; Erect; Multi-stemmed
Texture
Fine
Leaf color
Green
Leaf type
Simple
Leaf arrangement
Opposite
Leaf shape
Elliptical; Lanceolate; Oblong; Ovate
Leaf margin
Entire
Leaf feel
Smooth
Leaf size
1-3 inches long, < 1 inch wide
Hairs present
No
Leaf detail
The 1-2" leaves are three-veined, sessile, and appear on branching, hairy stems. They can be elliptical, lanceolate to ovate. Basal leaves are not present when the plant is in bloom.
Flower color
Blue; Pink; Purple/Lavender; White
Flower value
Showy
Flower form
Cyme; Panicle
Flower shape
Star; Tubular
Flower size
< 1 inch
Flower detail
Small 1/4" flowers appear in late spring to early summer and are present for approximately 1 month. The petals are fused into a cup or tube shape.
Bloom time
Spring; Summer
Fruit type
Capsule
Fruit size
< 1 inch long, < 1 inch wide
Fruit detail
The fruits grow as a capsule.
Stem color
Green; Purple/Lavender
Stem detail
The stems can be green or purple and 4 angled.
Wildlife & Ecology
Native status
Native
Origin
Native to Central and Eastern US
Distribution
Eastern U.S., AL, AR, CT, DC, DE, FL, GA, IA, IL, IN, KY, MA, MD, ME, MI, MO, MS, NC, NE, NJ, NY, OH, OK, PA, SC, TN, TX, VA, VT, WV
Wildlife value
Insects attracted by the flowers include long and short tongued bees, flies, butterflies, skippers and beetles.
Attracts
Bees; Butterflies; Pollinators; Specialized Bees
Play value
Attractive Flowers; Attracts Pollinators; Defines Paths; Easy to Grow
Food & Medicine
Fruit type
Capsule

Uses (ethnobotany)

Native wildflower makes a great ground cover.

Landscape Use
Landscape location
Lawn; Meadow; Naturalized Area; Patio; Slope/Bank; Walkways; Woodland
Landscape theme
Cottage Garden; Native Garden; Pollinator Garden; Rock Garden
Design feature
Border; Mass Planting; Small groups
Garden tags
#vigorous #slopes #native garden #spring interest #summer flowers #full sun tolerant #partial shade tolerant #native perennial #deciduous #groundcovers that can be mowed #groundcover #wildflower #self-seeding #native groundcover #pollinator plant #butterfly garden #pollinator garden #bushy #butterfly friendly #perennial #NC native #NC Native Pollinator Plant #moth friendly #bee friendly
Problems & Resistance
Insect problems
Slugs & Snails on Ornamental Plants; Slugs and Snails Found on Flowers and Foliage
Problems
Short-lived
Propagation
Division; Seed

Planted at Hunnicutt

Nobody’s planted this one yet.