Lysimachia vulgaris
yellow loosestrife
Overview
Lysimachia vulgaris is an upright, rhizomatous perennial in the Primulaceae growing 2-4 feet (60-120 cm) tall and spreading well beyond its 2-3 foot (60-90 cm) clump by creeping rhizomes. The lance-shaped leaves, 3-5 inches (8-13 cm) long, are arranged in whorls or opposite pairs along stiff, hairy stems. Yellow, five-petaled flowers about 0.6 inch (1.5 cm) across open in branched clusters at the stem tips in summer. The plant grows in wet ground along ponds, ditches, and stream banks and spreads aggressively by rhizome and seed, forming dense stands that crowd out other vegetation. It is listed as a noxious weed in Washington, Oregon, and several other states, and sale or planting is restricted under those state regulations. Hardy in USDA zones 4-8, it grows in full sun to partial shade and tolerates standing water but declines in dry soil. The spreading habit limits its use to contained sites or large naturalized areas. Native to Europe and western Asia, Lysimachia vulgaris has naturalized widely in North America wetlands.
Native Range
Lysimachia vulgaris is native to Europe and western Asia, growing in marshes, fens, wet meadows, and along the margins of ponds and slow streams. It has naturalized in wetlands across much of North America.Suggested Uses
Used at pond and stream margins, in rain gardens, and in contained wetland plantings where its spread can be managed. Confined beds, buried barriers, or large containers keep it from overrunning neighboring plants.How to Identify
Appearance
Size & Dimensions
Height2' - 4'
Width/Spread2' - 3'
Bloom Information
Yellow flowers open in summer, mainly June to August, in branched clusters at the top of the stems. Each cluster holds many flowers that open over several weeks. Flowering peaks at midsummer and tapers as summer ends.
Detailed Descriptions
Foliage 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
Lysimachia vulgaris grows in full sun to partial shade and thrives in consistently moist to wet soil with a pH of 5.5-7.5. It tolerates clay, loam, and silt and grows in shallow standing water at pond edges. Dry soil causes wilting and stunts the plant. Because it spreads quickly by rhizome and seed, growing it inside a buried barrier or a container limits its reach. Cutting off flower heads before seed forms reduces self-seeding. The species has few pest problems and needs no fertilizer in moist, fertile ground.Pruning
Cut spent flower stems back after bloom to limit self-seeding. Cut the whole plant to the ground in late fall or early spring to clear old growth. Dividing and removing rhizomes through the season holds the spread in check.Pruning Schedule
J
F
M
A
M
J
J
A
S
O
N
D
fall
Container Growing
✓ Suitable for container growing
Minimum container size: 5 gallons