Plant Tips

Suggestions that favor native plants
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Plant Tips:  Invasives Out ➔ Natives In

This Plant Tips page will provide suggestions of native plants that you can use to replace invasive plants in your own yard. HIPP will continue to add plant ideas to address some of the most common invasive plants that we find in Harpswell.  Click on the plant names listed below to expand content.

 

 

 

Invasive Out: Japanese knotweed (Reynoutria japonica); Native In: Sweet Pepperbush (Clethra alnifolia)
Photo of invasive plant Japanese Knotweed (Reynoutria japonica)
Japanese Knotweed (Reynoutria japonica)
Photo credit: Leslie J. Mehrhoff, Univ. of Connecticut, Bugwood.org		 Sweet pepperbush (Clethra alnifolia)
Photo credit: Bruce Patterson, GoBotany.com
  • Designated by the State of Maine as “Severely Invasive”.
  • Perennial shrub grows to 10’ in a dense stand; sometimes called “bamboo” because of its segmented stalks. 
  • Thickets release chemicals that suppress other plants, a trait referred to as “allelopathy”.
  • Common on private properties and along Harspwell’s roadsides.
  • Outcompetes native plants and provides limited value for native pollinators and other native wildlife.
  • Shrub that typically grows 3-6’ high and spreads to 4-6’ wide
  • Produces an abundance of sweetly scented flowers during the waning days of summer, when few other shrubs are in bloom.
  • Showy bottlebrush-like flower clusters, typically 3-5” in length, last for weeks.
  • Attracts a variety of butterflies and bees with its attractive fragrance. Leaves turn brilliant golden-yellow in fall before dropping for the winter.
  • Sturdy native shrub is remarkably adaptable, tolerating shade, variable soil moistures, and salty air, making it a valuable addition to woodland settings and coastal gardens.

Other native-to-Maine choices to replace knotweed:

  • Nannyberry (Viburnum lentago)
 https://extension.umaine.edu/publications/2583e/
  • Red twig dogwood (Swida sericea; aka Cornus sericea)
 https://extension.umaine.edu/publications/2569e/

 

Future Plant Tip