Lysimachia tenella
bog pimpernel
Western and southern Europe and North Africa
Overview
Lysimachia tenella, formerly Anagallis tenella and known as bog pimpernel, is a slender, creeping, mat-forming perennial of wet, peaty ground. Thread-like stems root as they spread, carrying small, rounded, opposite leaves 0.1-0.25 inch (3-6 mm) long to form low, bright green carpets only 1-2 inches (2.5-5 cm) high. In summer it produces upward-facing, funnel-shaped flowers about 0.4 inch (10 mm) across, pale pink with darker veins, held singly on slender stalks above the foliage. It grows in bogs, fens, wet heath, dune slacks, flushes, and the damp margins of pools, on acidic to neutral, nutrient-poor soil that stays wet through the year. The mat is delicate and shallow-rooted, so it cannot compete with taller, vigorous plants and is easily overgrown. It needs reliable moisture and open, sunny conditions, fading in drought or dense shade. Top growth dies back in winter, with stems reappearing in spring. It is grown in bog gardens and at pond margins for its pink summer flowers and creeping habit.
Native Range
Lysimachia tenella is native to western and southern Europe and North Africa, with a stronghold in the Atlantic, oceanic west. It grows in bogs, fens, wet heaths, dune slacks, and flushed, spring-fed ground. It is tied to wet, low-nutrient, acidic to neutral soils.Suggested Uses
Grown in bog gardens, at pond and stream margins, and in damp, sunny rockwork and containers kept wet, where its creeping mat and pink summer flowers show well. It works as a low carpet over consistently wet, acidic ground. Its need for constant moisture and open sun makes it unsuited to ordinary borders or dry sites.How to Identify
Appearance
Size & Dimensions
Height1" - 2"
Width/Spread8" - 1'4"
Reaches mature size in approximately 2 years
Bloom Information
Pale pink, funnel-shaped flowers open in summer, mainly June to August, in sun above the creeping foliage. They are held singly on slender stalks and close in dull weather. The flowers are visited by small bees and other insects, followed by tiny seed capsules.
Detailed Descriptions
Foliage Description
Bright 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 tenella grows in full sun to light shade on permanently wet, acidic to neutral, low-nutrient soil such as peat and wet sand. It needs constant moisture and tolerates shallow seasonal flooding but fails in drought or on rich, dry ground. It is hardy across roughly USDA zones 6 to 9 and dies back to creeping stems in winter. Because it is shallow-rooted and easily overgrown, it persists where taller plants are kept back. It needs little or no feeding on naturally lean wet soils. In containers or bog gardens it needs a wet, peaty mix that stays moist.Pruning
No pruning is required. Stray or overgrowing stems can be trimmed to keep the mat in bounds, and competing taller plants pulled back to stop them smothering it.Container Growing
✓ Suitable for container growing
Minimum container size: 1 gallons