Hypericum humifusum
trailing St John's-wort
Overview
Hypericum humifusum is a small, prostrate perennial with slender, trailing stems that spread flat along the ground, rooting here and there, the plant rising only 1-4 inches (2.5-10 cm) high but reaching 4-12 inches (10-30 cm) across. The wiry stems bear two raised lines and carry small, paired oval leaves 0.1-0.4 inch (3-10 mm) long, dotted with translucent and black glands and edged with occasional black dots. From June to September it produces small yellow flowers about 0.4 inch (8-10 mm) across, opening a few at a time at the stem tips, each with five petals sometimes flecked with black near the margins. It grows on bare, acid, sandy or gravelly ground, on heaths, woodland rides, and disturbed soil across western and central Europe. The plant favours open, low-competition ground and disappears as taller vegetation closes over. It is short-lived and renews itself from self-sown seed on open soil. The flowers close by midday in dull weather. Its prostrate, trailing habit and small flowers separate it from the upright H. perforatum and other taller St John's-worts of the same region.
Native Range
Native to western and central Europe. It grows on bare, acid, sandy or gravelly ground, on heaths, woodland rides, and disturbed open soil.Suggested Uses
Grown in heath gardens, gravel areas, and bare acid soils where low, trailing cover is wanted. It is used in wildlife and native-plant plantings on open, sandy ground. Its low habit suits the front of dry, sunny beds.How to Identify
Appearance
Size & Dimensions
Height1" - 4"
Width/Spread4" - 1'
Bloom Information
Small yellow flowers open from June to September, a few at a time at the stem tips. Each flower lasts a day or two and closes by midday in dull weather. Bees and hoverflies visit the flowers for pollen.
Detailed Descriptions
Foliage Description
greenGrowing Conditions
Sun Requirements
Requires 6-12 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
Hypericum humifusum grows on bare, acid, free-draining sandy or gravelly soils in full sun and tolerates a soil pH from about 4.5 to 6.5. It needs open, low-competition ground and fades where grasses and taller plants close in. The plant is hardy to USDA zone 6 and is short-lived, renewing itself from self-sown seed. It withstands drought and poor soil but not dense shade or rich, heavy ground. It spreads slowly by trailing, rooting stems. Bare, disturbed patches let its seedlings establish.Pruning
No pruning is needed. The trailing stems can be trimmed to hold the plant within bounds, or left to root and spread. Spent growth can be cleared in late winter before new shoots appear.Container Growing
✓ Suitable for container growing
Minimum container size: 1 gallons