Lysimachia clethroides
gooseneck loosestrife
Overview
Lysimachia clethroides is a rhizomatous herbaceous perennial in the primrose family, forming upright clumps 24–36 inches (60–90 cm) tall that spread steadily by underground runners to form broad colonies. The lance-shaped leaves are 3–6 inches (8–15 cm) long, alternate, and turn yellow to bronze in autumn. From early to midsummer each stem is topped by a tapering, arching spike of small white flowers about 0.3 inch (8 mm) across; the curved spike, 4–8 inches (10–20 cm) long, bends to one side and gives rise to the common name gooseneck loosestrife. The flower spikes straighten as the lowest flowers open first. It is native to eastern Asia and grows in full sun to part shade on moist, fertile soils. Its rhizomes spread aggressively and can crowd out neighboring plants, so it is often confined by barriers or grown in contained settings. It declines in dry, poor soils and may flop in deep shade.
Native Range
Lysimachia clethroides is native to eastern Asia, including China, Korea, and Japan, where it grows in moist meadows and along stream banks. It is widely grown as a garden perennial outside its native range.Suggested Uses
It is used in moist borders, pond and stream margins, and naturalized plantings where its spread is wanted or can be contained. It grows in cottage-style and cut-flower gardens in full sun to part shade.How to Identify
Appearance
Size & Dimensions
Height2' - 3'
Width/Spread2' - 3'
Bloom Information
Arching white flower spikes open from June to August, with the curved tips straightening as the lowest flowers open first. Bloom lasts three to four weeks. Removing spent spikes can prompt a lighter second flush.
Detailed Descriptions
Foliage Description
green, yellow to bronze in autumnGrowing 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 clethroides grows in full sun to part shade on moist, fertile soils and tolerates heavy, wet ground. In full sun with steady moisture it stands upright, while in dry soil or deep shade the stems weaken and lean. It spreads aggressively by rhizomes and is divided in spring or autumn to control its size. A buried barrier or a large container limits its spread. It needs no staking in adequate light but is divided every few years to maintain vigor.Pruning
Spent flower spikes are cut back after bloom to tidy the clump and limit self-seeding. Stems are cut to the ground in late autumn or winter once the foliage has died back. Lifting and dividing every two to three years restrains the spreading rhizomes.Pruning Schedule
J
F
M
A
M
J
J
A
S
O
N
D
fallwinter
Container Growing
✓ Suitable for container growing
Minimum container size: 5 gallons