“How do I get rid of creeping Jenny?” asks Carole, a Homegrown New Hampshire listener. “Any help would be greatly appreciated!”
Creeping Jenny (Lysimachia nummularia), also called moneywort, has long been used in gardens, pots and hanging baskets for its bright yellow color.
“How do I get rid of creeping Jenny?”
“It makes a lovely ground cover and can be a nice spiller out of containers,” says Homegrown NH Host Emma Erler, lead horticulturist at Kirkwood Gardens.
“Unfortunately, though, it is very aggressive and can easily escape garden beds and take over the understory of forest areas or, most importantly, wetland areas.”
As a prohibited invasive plant species in the state, nurseries, landscapers and individuals cannot sell, trade, or give away a creeping Jenny plant, according to the NH Department of Agriculture.
You are also prohibited from moving the plant (even in your own yard), and when removing it, you must completely kill or destroy the plant so that it does not spread.
So how to get rid of it?
Erler says hand-pulling or digging is a viable option if you have a small population of creeping Jenny and a lot of energy.
She also suggests smothering it with a heavy tarp, or with cardboard or thick layers of newspaper covered with mulch for a full growing season to ensure all the roots and stems decay.
Although you could use repeated applications of an herbicide, Erler prefers not to risk damaging the lawn and environment.
What other ground covers are of concern?
Ground covers spread quickly and thus are able to suppress weed growth, reduce soil erosion and nutrient leaching during rainfall, and provide cover for pollinators and other wildlife.
However some ground covers, like creeping Jenny, are extremely aggressive and may start to overtake lawns, gardens and natural areas unless carefully managed.
Common periwinkle (Vinca minor) is a popular ground cover that is on the NH plant species watch list. “If you plant it on a woods’ edge, it just creeps, creeps, creeps until that's the only thing that's left in the understory,” says Erler.
Two other ground covers of concern include bishop’s weed or goutweed (Aegopodium podagraria) and winter creeper (Euonymus fortunei).
“Bishop's weed or goutweed is a very old-fashioned plant that is very, very difficult to control,” says Erler. “And winter creeper is quite a nuisance in the Mid-Atlantic, so something we should watch out for here.”
Other aggressive ground covers include English ivy (Hedera helix), lily of the valley (Convallaria majalis), spotted deadnettle (Lamium maculatum) and chameleon plant (Houttuynia cordata).
Ground covers to choose instead
Erler suggests the following ground covers that are well-suited to New Hampshire’s climate:
- Barren strawberry (Waldsteinia fragarioides)
- Barrenwort (Epimedium species)
- Bearberry (Arctostaphylos uva-ursi)
- Canada anemone (Anemone canadensis)
- Bigroot geranium (Geranium macrorrhizum)
- Creeping phlox (Phlox stolonifera)
- Foam flower (Tiarella cordifolia)
- Pennsylvania sedge (Carex pensylvanica)
See you in the garden!
If you have a gardening question for Homegrown NH, email or send a voice memo to HomegrownNH@NHPR.org.
Homegrown New Hampshire is a collaboration between Squam Lakes Natural Science Center and NHPR.
