Marginal pond plant
Creeping Jenny
Lysimachia nummularia L.
A mat-forming, stoloniferous marginal plant native to the UK, Creeping Jenny suits pond edges and shallow emergent planting (to about 30 cm). It is an easy, wildlife-friendly groundcover but can be vigorous and needs containment.
PLANT PROFILE
About Creeping Jenny
Creeping Jenny (Lysimachia nummularia) is a mat-forming, stoloniferous perennial commonly used at pond margins and in bog gardens. RHS and pond-planting guidance place it in the emergent/marginal zone and a Chelsea planting list places it in the emergent band defined as 0–300 mm (0–30 cm) of water, so it is suitable for shallow water or damp margins. It produces yellow flowers in summer (described generically as "summer" in the supplied sources) and is valued for nectar and pollen at pond edges, contributing to pollinator resources and marginal habitat value.
The species spreads by creeping stems that root as they run, forming mats; this habit makes it effective as an edging groundcover but also explains why RHS cautions it can become vigorous and may become a nuisance if not managed. Standard pond practice in the supplied guidance is to plant marginal species from containers or baskets placed on the marginal shelf; L. nummularia is commonly supplied in small containers for this purpose. Propagation is supported by seed, division and (for cultivars) stem cuttings, and the plant is generally reported as pest- and disease-free.
RHS lists the species hardiness as H6 and notes that the species is typically deciduous, although some cultivars (for example 'Aurea') are described as more persistent/evergreen and lower-growing. Practical management advice from the supplied sources emphasises containment: plant in baskets or pots to restrict spread, trim back wandering stems, divide to reduce vigour, quarantine new material and avoid dumping plant material into watercourses. GOV.UK lists for England & Wales do not include L. nummularia on the statutory invasive plant lists, but the guidance also underlines the general legal and biosecurity requirement not to release plant material into the wild.
POND SUITABILITY