Invasive Plants

The ‘Dirty Dozen’ invasive plants

Fighting invasive plant species is daunting. The first problem for many of us is where to start. There are so many invasives that you encounter in local parks, your neighborhood and on hiking trails that tackling them seems to be an impossible task. There are several lists available, but those can include hundreds of plants. Thanks to Lewis Ginter Botanical Garden there is now a “dirty dozen” list of the 12 worst offenders that you’ll encounter in central Virginia. While the list is not comprehensive for Virginia or even Richmond, these 12 were chosen because they cause significant ecological harm, spread rapidly and are commonly sold at garden centers and nurseries. The Virginia Department of Conservation and Recreation’s Virginia Invasive Plant List is a more comprehensive list.

What is an invasive plant? For a plant to be considered invasive, it must meet two basic criteria. First, humans have deliberately or accidentally introduced the plant into an area where it did not evolve, and the plants must be ecologically and/or economically harmful to the areas where they have been introduced. According to the Virginia Department of Conservation and Recreation (DCR), these are common traits of invasive plant species:

  • They grow, mature, and spread quickly
  • They produce and disperse a lot of seeds
  • They out-compete native species for critical resources including light, water, and nutrients
  • They require significant amounts of time, energy, and/or money to control

The earlier you detect and remove invasive plants, the easier it will be! Once invasive plants have “made their home” in a space, they are much more difficult to control. It is also important to make the distinction between invasive and introduced, non-native species that do not cause harm when they are planted. On the other hand, invasive species (plant, animal, or fungi) pose risks to our conservation lands, parks, farms and even to our own backyards. In fact, they are one of the five major drivers of global biodiversity loss, along with habitat loss, over-exploitation, human population growth and pollution.

We will provide information on each of these offenders, including a description, what you can do to manage it or to help eliminate it from our communities and suggestions for alternative/native plants that are better choices.

More details will be provided about how to control specific invasive plants as we introduce each of Lewis Ginter’s “Dirty Dozen.” There are some basic tips on how to reduce the spread of invasives:

  • Learn more about them. This will also help with distinguishing between invasives and their native “look-alikes”.
  • When enjoying outdoor activities, prevent the dispersal of seeds from your shoes, clothing and pets.
  • Report invasive plants when you see them.
  • Stop buying them and use native plants for landscaping instead!

So … here are the “Dirty Dozen”

  1. Japanese honeysuckle (Lonicera japonica)
  2. Chinese privet (Ligustrum sinense)
  3. Japanese stiltgrass (Microstegium vimineum)
  4. Mulberry weed (Fatoua villosa)
  5. Tree of heaven (Ailanthus altissima)
  6. Porcelain berry (Ampelopsis glandulosavar. brevipedunculata)
  7. Oriental bittersweet (Celastrus orbiculatus)
  8. Autumn olive, Russian olive and thorny olive (Elaeagnus umbellate, angustifoliaand pungens)
  9. English ivy (Hedera helix)
  10. Nandina or heavenly bamboo (Nandina domestica)
  11. Cogon grass or Japanese blood grass (Imperata cylindrica‘Rubra’)
  12. Italian arum (Arum italicum)