Gardeners and land managers in North Carolina are no strangers to weeds. The combination of the climate and biogeography of our state creates a goldilocks growing zone for plant life. It is just warm enough for semi-tropical weeds, and just cool enough for the more northern problem plants. Oh the joys of managing plants!
But, there are some weeds that go beyond simply being a nuisance and move into being an invasive species that causes real ecological damage. This damage comes in many forms. In the case of the fairly new Asiatic Hawksbeard, Youngia japonica, you may not realize it is choking your forest until it is too late!
Another dandelion? What’s the problem?
The flowers of Asiatic hawksbeard look like tiny dandelions, but don’t let the size fool you. Each of those yellow flowers can make dozens of seeds, which fly on the air and spread quickly into the surrounding area. Usually in areas where you are not looking!
Asiatic hawksbeard isn’t like the typical dandelion. Left to its own devices, it will create monocultures of seedlings that crowd out any other species and will flower prolifically and produce copious amounts of seeds in days. Unlike many of our dandelions, Youngia japonica prefers part sun to deep shade, and is adept at moving into high-quality woodland habitats. It can grow in moist and dry soil, and clay and loam. Its adaptability and prolific life strategy make it a formidable invasive species.
The plants are plain, nondescript whorls of fuzzy, light green leaves when they are not in flower. They come up in the mid- to late-winter in North Carolina and are usually flowering in April and May for us. This is a great time to observe them because their leaves can blend in with lawns, green areas and native foliage. They grow as large or as small as they need to to survive. They can withstand mowing in a lawn setting, and will send out new flowers within days of mowing.
Another weed from Asia?
Youngia japonica hails from Eastern Asia and Australia and has been spreading
throughout the globe for about a decade. It is hypothesized that the seeds have blown on the wind, were brought in on contaminated soil or packing material, or were transported on people’s shoes. At this point it is hard to say and it will be an invasive species we will be combating for decades to come.
We always seem to be talking about invasive plants from Asia, and that is because the climate is so similar, plants find it easy to grow here in the Southeastern US. It isn’t that they aren’t welcome. The problem is when these invasive plants do not have the natural predators and equal plant competitors here like they do in their Asian native ranges, which causes the plants to grow unchecked.
Pay Attention to Your Woods!
Make sure to keep an eye out for this new(-ish) invasive species. We are fortunate in Lee County to have many high-quality tracts of forest still intact and Youngia japonica is a threat to that quality. It has been observed in the County!
If you see it, pull up the plants or spray the rosettes with herbicide. If there is a larger patch, treat the area with herbicide and revisit the site for follow-up treatments, making sure to check back throughout the summer, as the plants can germinate and go to seed multiple times a year. If you see it in flower and notice seeds drop, make sure to follow back around to the site to pull up or treat returning seedlings. They WILL be there. Be mindful of surrounding native vegetation! Be selective about where you are treating and always follow label directions. Just cutting off the flowers will NOT stop it. It will flower again!
Unfortunately, for those of you who have been managing the same property for years or decades, this invasive plant can affect you as well. Our modern climate and how much we move around requires diligent management and strong observational skills. Invasive species move around in many different ways and your property is connected to others’, even if you have good management practices.
Amanda Wilkins Bratcher is the Horticulture Agent for North Carolina Cooperative Extension in Lee County.