Sunday, August 4, 2019

Remove Invasive Plants Early for Best Results


I drove up to North Carolina last week, driving on US-23 N/US-441 N to get to the Cullowhee Native Plants Conference. After the turnoff from Franklin, the road rises high, with potentially scenic views but the roadside has been plagued with princess tree infestations in the past. Those trees were no longer visible because they’d been swallowed up by a humongous expanse of kudzu. What an awful sight it was to see the beautiful mountains in the distance while the entire roadside had been transformed into a shapeless blob of kudzu.

Kudzu in Cherokee, NC (Credit: Tammy Mercure)

I didn’t stop to take a picture (the roadside looked a bit dangerous for stopping on), but this picture by Tammy Mercure in Cherokee, NC gives a pretty good representation of what I saw. I hadn't been up there for a couple of years and this certainly didn’t happen overnight, but it clearly could have been controlled by property management when the invasion first started. Unfortunately, infestations that appear (distribution thanks to wind, wildlife, or water spread of seed) on large and unmanaged properties contribute significantly to the increasing acreage of invasive plants.

A friend recently moved to a new property and the backyard included a rather wild and weedy area. Of course, we both realized the potential in the area for growing sun-loving native pollinator plants and immediately spotted a few worthy plants already growing there. I ventured into the space to check out something with yellow flowers and found a watermelon-sized clump of kudzu sitting in the middle! Using her shovel, I carefully removed it. If I hadn’t, it would have grown and grown over the next few years until it dominated the space, spreading into the trees in the natural area behind her property. That’s how it gets started: one plant, ignored or unnoticed and allowed to spread.

All of us should be careful to spot and deal with plants that can spread; the sooner we remove them, the less work it is. Other highly invasive plants to watch for include:

  • Stiltgrass (Microstegium vimineum), often found in part-shade areas; it is an annual that drops thousands of seeds and goes quickly from early appearance to infestation.
  • Mulberry weed (Fatoua villosa), often found in mostly sunny garden beds; it is also an annual with lots of seeds.
  • Privet (Ligustrum spp.), mahonia (Mahonia bealei), and Ugly Agnes (Elaeagnus spp.) are shrubs that pop up initially as single seedlings spread by birds; they grow quickly. All of these are evergreen.
  • Heaven bamboo (Nandina domestica), burning bush (Euonymus alatus), Japanese barberry (Berberis thunbergii), bush honeysuckle (Lonicera maackii, and others) are also shrubs that pop up initially as single seedlings spread by birds; these shrubs are showing up more than they used to and thriving with the change in temperatures.
  • Japanese honeysuckle (Lonicera japonica), English ivy (Helix hedera), and vinca (Vinca spp.) are evergreen vines and ground covers. Non-native wisteria (Wisteria sinensis) is another vine.
  • Bamboo (I am not even sure which ones are taking over some roadsides) is very hard to control once it gets going.
  • Tree of heaven (Ailanthus altissima), ornamental pear (Pyrus calleryana), mimosa (Albizia julibrissin), princess tree (Paulownia tomentosa), and chinaberry (Melia azedarach) are invasive trees.
  • Emerging invasive plants in Georgia also include Japanese knotweed (Fallopia japonica) (I've seen this growing in Cherokee County and points north); garlic mustard (Alliaria petiolata) (in the North Georgia mountains); and Japanese chaff flower (Achyranthes japonica) (this is already present in Atlanta); Japanese spirea (Spiraea japonica) (in the North Georgia mountains); and porcelain berry (Ampelopsis brevipedunculata) (in the metro Atlanta area).
  • See the whole list here.

A small appearance of Microstegium vimineum

An infestation of Microstegium vimineum just across the street;
the mow and blow crew just mows around it!

When you see these plants, even if it is just a few of them, get rid of them quickly to reduce work for yourself as well as reduce the future spread. It only takes a season or two of neglect to have a real problem on your hands.

1 comment:

  1. Ugh, mulberry weed and it's companion chamber bitter are two weeds going unnoticed here in greater Houston but having a signficiant impact to the ecosystem. So glad we don't have kudza but Chinese tallow is our big 'baddie'.

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