Creeping jenny or Lysimachia nummularia, a species of plants from the Primulaceae (primrose) family is indigenous to Europe but naturalized in North America where it is considered invasive in some regions.
This vigorous, evergreen perennial grows about 2 – 4 inches high, 12 – 18 inches wide. This is a perennial in mild climates and care should be taken when planting it in areas where you don’t want it to spread — a single plant can spread rapidly to an indefinite length by stem-rooting.
The leaves are green or gold and rounded in shape. It blooms in summer, producing yellow cup-shaped flowers with 4 – 5 petals that are less than an inch in diameter.
These upturned flowers don’t last very long but they are particularly cheery to look at as they meander along pathways or spill from a pot, a beautiful tribute to summer.
While it usually grows near ponds or wet ground, it can also tolerate drier conditions although its growth might not be as vigorous.
This low-grower is best cultivated for its leaves and makes an excellent plant to be used as ground cover. Some people grow these plants in containers where it transforms into an elegant, drooping plant that spills over the edges of pots and doesn’t pose a threat of invading your garden. Despite it often being a nuisance in gardens, it’s a plant that balances in between being a beautiful ornamental or an invasive one.
However, the “Auria” or golden variety grows a lot slower and is less invasive than the green variety.
Generally, these plants are somewhat hard to remove manually as even a small piece of stem left behind will re-root and grow. If you take good care of the plant, you can control its bad reputation and grow it as a beautiful ornamental. However, if you keep your soil dry and limit watering, this will limit its growth and spread to a certain extent.
When planting it in your garden, pair it with tall plants to prevent it from smothering other low-growing plants. You can also create a nice display in your containers by combining its color to contrast with plants bearing dark green leaves and brightly colored blooms.
This plant thrives under full sun or partial shade, although the color of the foliage leaves will vary based on how much sunlight the plant gets – yellow under full sun and pale green under partial shade.
In hotter climates, provide the plant with a bit of shade from the afternoon sun as harsh sunlight might cause the foliage colors to fade and also cause wilting.
It needs moist and damp soil to grow and thrive, so water it regularly. The soil should never be allowed to turn dry unless you want to control its spread, although this will affect foliage color.
This plant can tolerate high humidity and also low humidity as long as you water it well. Limit watering when it grows under high humidity.
It is very hardy and can survive lows of -30°F and come back in spring. Ideally, it will thrive in temperatures between 55 – 75°F. It can grow well in zones 4 – 10 although the leaves will become dark red when the temperature falls in winter.
This plant prefers moist and well-draining sandy, loamy or clayey soils although it can even grow in wet soil along riverbanks, ponds, and streams.
This plant grows well in containers and seldom needs repotting unless it gets root-bound – and that is very rare. You can prevent it from getting overcrowded by pruning away long stems that droop too low or by dividing and propagating the plant.
This resilient plant is very easy to propagate since it is naturally spread by both seeds, rooted stems, by cuttings that can also be rooted in water or by dividing it. The simplest way to propagate new plants is by dividing the plant, dig up a part of an established plant to separate and plant it elsewhere.
Cuttings also easily take root in soil or water by cutting off a length of stem and planting it in soil or water – as simple as that. You don’t have to use rooting powder as well.
Since the stems grow roots wherever they touch the soil, cut off a rooted stem and plant. This plant’s easy way of spreading can be invasive and hijack your garden if you’re not careful.
Lightly fertilize this plant when it gets established with a general all-purpose liquid solution in spring however, this prolific grower seldom needs feeding.
Trim off dead stems of the plant before winter starts and it will grow back in spring easily.
This plant does not typically have issues with pests or diseases, although slugs and snails might attack the foliage, sometimes completely defoliating the plant when there is a huge infestation.
While plants might suffer such damage, they will usually survive and new growth will soon appear. Handpick these pests off the plant and use slug traps near the plant, crushed eggshells and coffee grounds will also help deter these pests.
This plant has been noted to be more vulnerable to diseases in summer, hot weather, and high humidity creating perfect conditions for fungal infection. These diseases can affect the plant severely and curtail growth by damaging the foliage and stems.
Symptoms include yellow stem rot, brown leaf rot, and slimy foliage; the first appearance of the disease is soggy spots on the foliage, followed by yellow-brown spots, and finally, the stems of the plant become yellow, decaying, and finally dying.
Depending on the extent of damage to the plant, it might have to be dug up and disposed of. Turn over the soil where it was planted and let it dry out. However, it’s easy to save the plant by snipping off healthy stems and propagating them elsewhere.
The only way to prevent fungal problems is to reduce watering and provide the plant with better air circulation.