Creeping Jenny Growing, Planting, Facts & Care (Lysimachia nummularia)
Lysimachia nummularia is a ground cover plant that is commonly known as moneywort, twopenny grass, and creeping jenny. It is a fairly hardy member of the Primulaceae family, which includes a wide variety of herbaceous primroses. Under this family, the Lysimachia genus is notable for producing floral oils that are favored by several species of bees (Macropis sp.). These oils become a vital component and building block of their hives’ cells.
Creeping jenny is just one of almost 200 species under Lysimachia, and is highly popular for its use as an ornamental plant in temperate regions. It is native to Europe but is now widespread in many wetland areas across North America.
One of the most popular cultivars of this evergreen plant is called ‘Aurea’ or golden creeping jenny. It produces expansive mats of oppositely arranged orbicular leaves that arise from trailing stems. The stems, which can be oriented downwards from an elevated area, can grow to a length of 6 inches (15 cm). Under favorable conditions, a single plant can reach a spread of 12 – 18 inches (30 – 45 cm), making it quite vigorous as a ground cover option. The bright green to “golden” leaves are aptly matched by equally striking yellow blooms in the summer! The flowers occur singly, are cup-shaped, and are quite petite as they grow to just an inch across.
Facts, Benefits & Uses of Creeping Jenny
Creeping jenny fits all the criteria for an ideal pond edge or container garden plant. Its growth habit and the orientation of its trailing stems may be utilized to create a highly textured cascading effect. This effect can be wielded to add height to a garden, accentuate organic textures, fill in spaces between rocks and logs, or blur the edges of a water feature.
If you intend to grow this plant in your garden, do keep in mind that it may spread quickly, particularly in damp soil. It has the potential to be invasive and suffocate other native plants as its trailing stems are capable of producing specialized roots and offshoots. If located outside of its native range, you may need to restrict its spread by planting it in pots instead of directly into the ground.
Apart from its ornamental uses, creeping jenny has many herbal benefits. Like many nutritious vegetables, it is rich in secondary metabolites such as flavonoids, saponins, and other polyphenols. These are associated with a host of health benefits for their antioxidant, antibacterial, and anti-tumor effects.
Creeping Jenny Growth, Hardiness & Climate
Creeping jenny can grow in a wide variety of conditions, but will thrive best in consistently moist soil. It can even survive in a few inches of freshwater, where its trailing shoots may provide shelter to juvenile fish and amphibians. In dry, poor soil, its growth and spread are impeded significantly. This plant spreads by multiple means: underground rhizomes, self-seeding, and by rooting in areas where its shoots come into contact with rich soil. It’s a great option if you require a plant that can quickly cover bare areas around a pond or water garden. It can even withstand a light amount of foot traffic!
Hardy to USDA zones 3 – 9, creeping jenny develops its best colors under full sun exposure. It can withstand dappled sunlight or shade as well, but is more likely to develop green (instead of golden yellow) leaves under these conditions. In especially hot summers, its foliage may require shade from the sun to ensure that they don’t grow parched or get sunburned.
How to Plant Creeping Jenny
Creeping jenny can be planted via seed and propagated further via rhizomes or stem cuttings. It is also easily propagated by taking shallowly rooted patches of the plant and re-planting these in other areas. To grow creeping jenny by seed, create a germination set-up in a greenhouse or a protected area of your garden. Ideally, this should be done in spring or summer. Use clean, fertile soil in pots that are submerged in a few inches of water to ensure that the soil remains moist throughout the germination period. Once seedlings are large enough to handle, transfer them to individual pots or containers where they can be spaced apart. Stem cuttings can easily be rooted in water prior to planting them into soil.
If you have a well-established carpet of creeping jenny, you can simply dig out a few patches, making sure to keep the roots and shoots largely intact. Replant these patches into a few inches of fertile, moist soil when climate conditions are mild or stable. These will eventually produce more roots and offshoots and spread out. Make sure that patches are initially placed 12 – 18 inches (30 – 45 cm) apart to accommodate the full spread of this plant and to prevent overcrowding.
How to Care For Creeping Jenny
Due to its ease of care and maintenance, creeping jenny is a recipient of the RHS Award of Garden Merit. Its colonies are not prone to diseases or pest invasions, and they are notable for being deer resistant. Simply make sure that the soil is regularly provided with water or kept moist by a nearby source. Trim trailing shoots according to your preferences.
As slightly acidic to neutral soil is best for this species, it may be fertilized with pond water. It can also take minimal flooding from a pond as long as its roots are intact or grown in stable soil. Bear in mind that if you would like to remove overgrown patches of this plant, any remaining fragments or roots may generate new plants. Restrict its growth to within pots to prevent aggressive spreading.
How to Winter Creeping Jenny
Creeping jenny is native to areas that experience marked seasonal fluctuations. Its roots are able to withstand winter conditions, but its leaves and shoots will generally die back when exposed to extended cold periods. Creeping jenny will naturally survive outdoors if planted directly into the ground, though you may opt to transfer those in containers and hanging baskets into a greenhouse or cold frame. This would allow you to conserve the plant’s shoots over winter and use them for propagation.
If leaving your plant outdoors, you can either trim your creeping jenny plants before the first frosts or simply wait for its shoots to die back. Make sure to remove any dead or decaying plant parts to prevent bacterial and fungal growth. In the coming spring, shoots will naturally arise once more and quickly spread to form a carpet.
Is Creeping Jenny Invasive or Toxic?
Due to its creeping nature and mechanisms of spread, creeping jenny can grow aggressively and outcompete native ground cover plants. It is invasive in some areas of the US, particularly in Indiana, North Carolina, Virginia, and several states around the Great Lakes region. It has reportedly escaped into many natural areas and outcompeted several native plants. This has resulted in compromised food webs and biodiversity losses. Chemical and mechanical means, along with the occasional use of controlled fires, have been utilized to combat its spread.
Some creeping jenny cultivars that are prized by the horticultural industry are less aggressive in terms of growth and spread. In particular, the ‘Aurea’ and ‘Goldilocks’ cultivars would be better options to cultivate as these may be easier to control in your garden.
Creeping jenny is often mistaken for other invasive plants, such as creeping charlie (Glechoma hederacea). This is a type of ground ivy that likewise has a creeping habit and leaves that arise opposite one another along trailing stems. Unlike creeping jenny, this look-a-like plant is mildly toxic and can cause digestive problems for grazing animals (particularly cats and horses). Creeping jenny itself is fortunately non-harmful despite its vigorous spreading capabilities.
Is Creeping Jenny Edible? Will Fish & Animals Eat it?
Fancy the odd cup of tea every now and then? You can brew the leaves and flowers of creeping jenny to produce a warm herbal concoction. Apart from their use in tea, this plant’s parts are not generally known for their culinary uses. They are safe to consume in limited quantities, however, as they don’t contain any toxins.
The foliage of creeping jenny can occasionally be grazed upon by many small animals, particularly slugs and insect larvae. Fish and other pond inhabitants may take a nip or two, but are generally not known for eating this plant. As it is a rapid grower, mature plants can withstand a fair amount of grazing and would thus not require protection from your pond animals or visitors.
Where to Buy Creeping Jenny & Seeds? (UK & US)
Creeping jenny can be purchased from plant nurseries across its native range. Potted varieties are also available from several online gardening or aquascaping stores. Many pot sizes, from the pint to the gallon, are available. These can be planted directly into hanging baskets or pots or can be placed along your pond’s edges outdoors. If you are located in the US, it is advisable to consult your state’s list of restricted or invasive plants prior to making a purchase.