Q: I’ve been perplexed with a plant that my mother threw out decades ago which is spreading as a groundcover in the woods. Can you identify it, and should it be removed or eradicated? — Joan B., Detroit Lakes, Minn.
A: The groundcover is called Lamium, which is derived from its botanical genus of the same name. Lamium is a well-known perennial groundcover used in landscapes and offered for sale in garden centers. It’s sometimes called deadnettle, although the name lacks market appeal.
There are several closely related species of Lamium. The type you’ve photographed, Lamium galeobdolon, sometimes listed as Lamiastrum, has the common name yellow archangel deadnettle, and does spread outward in groundcover fashion. It can be a useful landscape plant in the right location, but several states have declared it an invasive species, including North Carolina and Washington state, whose noxious weed board says, “Yellow archangel escapes from residential plantings, becoming very invasive and forming dense mats of groundcover, outcompeting native vegetation.”
Such cautions come from states with mild winters, and I’m not aware of similar warnings in the Upper Midwest, where winters might have a containing effect. Lamium has been spotted in Minnesota woods adjacent to residential areas, similar to your situation, but it doesn’t appear to be spreading aggressively. Keep an eye on the area, and if the groundcover appears to be aggressively choking out other vegetation, judicious use of herbicide might be warranted.
Garden centers sell less-aggressive, named varieties of Lamium that perform beautifully in shaded landscapes, including types with pink and lavender flowers.
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Q: We have an ornamental crabapple tree in our yard that was planted by the previous owner, so we don’t know exactly what variety it is, but we’d like to know. The blossoms are pink and the leaves are dark green with a hint of dark red. The tree is now 20-something and unlike most crabapple trees in our neighborhood, it holds its little apples all winter. Then, as the weather warms, the tree hosts a feeding frenzy of robins, and within a week the thousands of apples are gone.
It took us several years to figure out what was happening as the tree seemingly lost all its apples in a very short time, but never created a mess in the yard. Any help would be appreciated, and maybe other bird lovers would appreciate the annual spectacle if they planted the same variety. — Jim L., Fargo.
A: The ornamental crabapple that you describe fits the variety Red Splendor, which was developed during the 1970s, became very popular and was widely planted for the next 30 years. It's still available from garden centers and is a nice variety.
When fruits cling on trees during winter, they’re termed "persistent." Red Splendor crab is well-known to have fruits that are extremely persistent, clinging until spring, and birds love them as they thaw. There are also many reports of intoxicated birds which ate crabapples after they’ve fermented. Unlike many of the messy crabapple varieties, Red Splendor holds its fruit well until they are cleaned up by the birds, with very few fruits dropping to the ground.
A possible drawback of Red Splendor is its occasional susceptibility to diseases such as apple scab, a fungal disease that can cause yellowing and early dropping of a portion of leaves during humid, rainy summers. Newer varieties of ornamental crabapples are continually being developed with increased disease resistance. When shopping at locally owned garden centers, if newer varieties are offered, check for the keywords “persistent fruits” or “fruits cling all winter” for the same bird-attracting effects of Red Splendor.
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Q: You mentioned buckthorn shrubs or small trees recently, and how they can spread invasively. I’ve got some growing on the edges of our shelterbelt. Aside from cutting them down, how can I get rid of them? They’re popping up all over. — Jim L., Horace N.D.
A: Defeating an established buckthorn thicket require persistence, because they spread readily as their purple-black fruits disperse seeds. Simply cutting them back temporarily reduces the fruiting, but doesn’t destroy the winter-hardy root system, which quickly resprouts and rapidly regrows.
To kill established buckthorn, after cutting their trunks flush with ground level, immediately saturate the cut surface with an herbicide whose active ingredient is 2,4-D. Then, cover the cut surface with soil to seal in fumes.
If you have a gardening or lawn care question, email Don Kinzler, NDSU Extension-Cass County, at email@example.com. Questions with broad appeal may be published, so please include your name, city and state for appropriate advice.