Houstonia purpurea
summer bluet
Overview
Houstonia purpurea is a clump-forming herbaceous perennial in the madder family, native to the eastern United States, growing 4-18 inches (10-45 cm) tall on slender, leafy, upright stems from a fibrous root. Unlike the basal-leaved spring bluets, it carries paired, stalkless, oval to lance-shaped leaves 0.5-1.5 inches (1.3-3.8 cm) long up the stem, each with three to five visible veins. From late spring into summer, small four-lobed funnel-shaped flowers about 0.25 inch (6 mm) across open in branched clusters at the stem tips, pale purple, lilac, or white with a paler or greenish throat. Tiny round seed capsules follow. The plant grows in open woods, clearings, slopes, and rocky banks, often on thin or acidic soils. It is hardy in USDA zones 4-8 and spreads slowly into small colonies. The individual flowers are small, and the plant can be short-lived in heavy, wet ground.
Native Range
Houstonia purpurea is native to the eastern and central United States, from Pennsylvania and Maryland west to Iowa and Missouri and south to Georgia and Alabama. It grows in open upland woods, forest edges, glades, rocky slopes, and clearings, often on acidic or thin soils.Suggested Uses
Used in native woodland gardens, shaded rock gardens, and naturalized clearings, and along path edges where its low clumps suit small spaces. It draws small native bees and self-sows into informal drifts.How to Identify
Appearance
Size & Dimensions
Height4" - 1'6"
Width/Spread6" - 1'
Reaches mature size in approximately 2 years
Bloom Information
Flowering runs from May through July, sometimes into August. Branched clusters of small lilac, purple, or white funnel-shaped flowers open over several weeks at the stem tips. Small bees and flies visit the flowers, and round capsules ripen by late summer.
Detailed Descriptions
Flower Description
lilac to whiteFoliage Description
greenGrowing Conditions
Sun Requirements
Requires 4-8 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight
Care & Maintenance
Care Guide
Grows in part shade to full sun on moist to dry, well-drained, acidic to neutral soils, including thin and rocky ground. A soil pH of 5.0-6.5 suits the species, which favors low-fertility, acidic conditions. It needs steady moisture in spring and tolerates summer dryness once established. Heavy, wet, or rich soils shorten its life and can cause rot. It self-sows where the ground stays open and lightly mulched. No feeding is needed on lean woodland soils.Pruning
No routine pruning is needed. Spent stems can be sheared after flowering to tidy the clump and may bring a light second bloom. Plants can be left to self-sow or cut back once seed has dropped.Pruning Schedule
J
F
M
A
M
J
J
A
S
O
N
D
summer
Container Growing
✓ Suitable for container growing
Minimum container size: 1 gallons