Look out for wintercreeper

wintercreeper vines climbing up trees in a forested area
Wintercreeper euonymus (Euonymus fortunei) overrunning a woodland floor and climbing tree trunks. Photo: Ryan Armbrust, Kansas Forest Service, Bugwood.org.

Q:  I realize English ivy is widespread in Maryland, but there are some evergreen vines clinging to trunks that look a bit different than typical ivy leaves. Are they native, or should they too be removed?

A:  An evergreen climber I see covering tree trunks in parks which might be confused for English ivy at a distance is wintercreeper (sometimes written winter creeper; Euonymus fortunei). This non-native invasive acts like English ivy in that it’s a groundcover when no support to climb is present, and a clinging vine when trunks or walls are available.

This species also has negative impacts on the trees and our ecosystem and should be removed if growing on your own property. Parks manage invasives as best they can, but with limited resources, we can do our part by not cultivating the species likely to spread into them, even if we don’t live immediately next to parklands. Weed Warrior volunteer programs exist, such as in Montgomery County, if you wish to be trained in invasive plant ID and to help with their removal on public lands. While wintercreeper has been banned for sale by the Maryland Department of Agriculture since 2018 as a Tier 1 invasive plant, established plants in the region can still mature enough to produce fruit (berries) that wildlife then inadvertently spreads into natural areas. Long a popular landscaping groundcover due to those vibrantly green leaves (and the variegated forms for their color), I always recommend removal and replacement with alternatives, preferably a medley of native species instead.

As with English ivy, it’s safest for the tree to simply sever the climbing wintercreeper stems’ connection with the roots in the ground and let them slough off the trunk on their own as they dry out and disintegrate. Even though they attach via root-like structures, those aren’t functional roots and no moisture or nutrients are absorbed by them. Pull up, smother (deny them light), or spray any running stems covering the ground. As with any tenacious weed, eradicating an established patch of this species may take time and repeated efforts at removal before finally being successful. Be vigilant, because birds could always re-introduce it in a future year. (Invasive plants…the gift that keeps on giving.)

By Miri Talabac, Horticulturist, University of Maryland Extension Home & Garden Information Center. Miri writes the Garden Q&A for The Baltimore Sun and Washington Gardener Magazine. Read more by Miri.

Have a plant or insect question? The University of Maryland Extension has answers! Send your questions and photos to Ask ExtensionOur horticulturists are available to answer your questions online, year-round.

Nasty weed, Jack-in-the-pulpit look-a-like: Pinellia ternata – Featured Video

Wish this enemy on no one because at the professional gardens they discard the contaminated weedy soil. Or they have resorted to sifting the soil to remove the corms. It is a bad weed. And solarization does not outlast the corms’ durability!

By Joyce Browning, Harford County Master Gardener. Follow on Harford County Master Gardeners on Facebook

My Pachysandra is Dying, What Can I Plant in Its Place?

landscape in partial shadeResident seeks groundcover options to replace Pachysandra. Photo: University of Maryland Extension / Ask an Expert

Q: My Pachysandra is Dying, What Can I Plant in Its Place?

A patch of Japanese Pachysandra in my yard was formerly healthy but in the past three years, it has died back. I would like to plant deer-resistant plants or groundcover in its place. Can you recommend some perennials I can try? This area gets filtered sun most of the day.

Answer: Volutella is a common fungal disease of Japanese Pachysandra that attacks both the leaves and stems and causes dieback symptoms. It is most severe in overgrown plantings and is often associated with scale (insect) infestations. This may have contributed to the decline of your plants.

It is a good idea to consider different options for this space. In addition to its susceptibility to Volutella dieback, Japanese Pachysandra has escaped garden cultivation and is now invasive in some natural areas of Maryland. We no longer recommend planting it. In the forest understory, it outcompetes native plants such as our spring ephemeral wildflowers and the wildlife (insects, birds) they support.

japanese pachysandra in a forested area
Invasive Pachysandra terminalis covers a large area of forested ground in Howard, County, Maryland. Photo: C. Carignan

There are other groundcover choices that are unique, beautiful, non-invasive, and adapted to Maryland’s growing conditions. For a partially shaded, moist area, try a combination of ferns – Christmas fern (Polystichum acrostichoides) and marginal woodfern (Dryopteris marginalis), sedges – blue wood sedges (Carex glaucodea or Carex laxiculmus) and Pennsylvania sedge (Carex pensylvanica), Canadian ginger (Asarum canadense), golden groundsel (Packera aurea), foam flower (Tiarella cordifolia), and creeping phlox (Phlox stolonifera). Some of these plants also support pollinators.

native plants garden
Groundcover plants were in bloom in April in the native plants garden at Camden Yards, Baltimore. From front to back: Phlox, Foamflower, Golden Groundsel. Photo: C. Carignan

Additional Resources

Planting Groundcovers | Home & Garden Information Center

Twelve Easy Native Plants for Shade | Montgomery County Department of Environmental Protection

Groundcovers | Plant NOVA Natives

By Christa K. Carignan, Maryland Certified Professional Horticulturist, Coordinator, University of Maryland Extension Home & Garden Information Center

Have a plant or insect question? University of Maryland Extension’s experts have answers! Send your questions and photos to Ask an Expert.

Q&A: Is this giant hogweed or poison hemlock?

poison hemlock
Poison hemlock can be mistaken for giant hogweed

Q: I think I might have giant hogweed on my property, or maybe it is poison hemlock. How can I tell for sure?

A: Giant hogweed (Heracleum mantegazzianum) was found recently in Clarke County, Virginia, and it has raised awareness and concern about the plant – and rightfully so. The plant produces toxic sap that can cause very severe skin inflammation. We have received a lot of questions about it lately.

poison hemlock
Poison hemlock Photo: E. Nibali

What you have here is NOT giant hogweed. It is poison hemlock (Conium maculatum), which is much more common. The ferny foliage makes it possible to distinguish it from giant hogweed.

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What Can I Do About My Neighbor’s Plants Coming Onto My Property?

bamboo
Bamboo. Photo: Chuck Bargeron, University of Georgia, Bugwood.org

Maryland property owners are limited to self-help when dealing with plants encroaching on their properties. This is not legal advice.

Have a neighbor who has planted bamboo or another invasive plant species near your shared property line and now that plant has started encroaching on your property? What can you do in this situation? Maryland has only one decision discussing damage from plants growing on a neighbor’s property. In Melnick v. C.S.X. Corp., the Court of Appeals of Maryland limited landowners to self-help to remove invasive plant species from growing on your property. The courts in Maryland have found that “it is undesirable to categorize living trees, plants, roots, or vines as a “nuisance” to be abated. Consequently, we decline to impose liability upon an adjoining landowner for the “natural processes and cycles” of trees, plants, roots, and vines.” (Melnick, 520-521). Self-help means it will be up to you to remove the roots, limbs, vines, and other plant debris and not the neighbor who planted the invasive plant species. A neighbor cannot seek damages in court for the damages caused by the invasive plant species.

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How Invasive is Chinese Silvergrass?

Chinese silvergrass, Miscanthus sinensis, is a beautiful ornamental grass. In its native range, it inhabits disturbed areas and meadows. Here in North America, it escapes cultivation to occupy similar types of places, and, given enough time it can displace native meadow vegetation. If you have not yet had the opportunity to see how invasive this species can be, then this is your chance.

I was driving home from a meeting in Baltimore County when I started to notice occasional Miscanthus plants growing in unkempt areas along the roadside. This went on for a mile or two, and then suddenly I arrived at what quite clearly was the epicenter. The lighting was perfect, so I pulled over, grabbed my little video camera and went for a walk around the area to see how extensive the infestation might be. The footage posted here is unedited so you will see exactly what I saw on that walk.

I mentioned the Miscanthus to a friend who used to walk past this substation to get to school, and he told me Miscanthus was planted at the substation in the mid-1980s, and that it has spread a little each year ever since. Now it occupies several private properties, and as per his description “miles” of the local power lines.

According to the U.S. Forest Service, Miscanthus spreads by both seeds and rhizomes. It is very difficult to eradicate once established because even small bits of rhizome will start new plants. They also warn that it is highly flammable, and at this time of year it should be considered a fire hazard.

What about you? Do you see Miscanthus escaping in your area? Leave us a comment!

Learn more about invasive plants in Maryland.

By Sara Tangren, Ph. D
Agent Associate | Master Gardener Trainer | Sustainable Horticulture and Native Plants