Issue 1, April 20, 2015

Illinois Invasive Plant Phenology Report for April 14, 2015

Several invasive plant experts from around the state are continuing their series of reports focusing on the phenology of invasive plants in Illinois. The intent of these reports is to provide an update on the development of invasive plants across the state of Illinois--what plants are in bloom, leafing out, setting seed, or senescing in different areas of the state.

Readers are encouraged to share what they see in their area of the state by emailing Chris Evans, Invasive Species Campaign Coordinator of the Illinois Wildlife Action Plan (

Here is the first invasive plant phenology report for Illinois of the 2015 growing season. 
Contributors include Cathy McGlynn, Mike Daab, Caleb Grantham, Nick Seaton, and Eric Smith.
*Report based upon observations on April 8-14, 2015

Southern Illinois

  • Multiflora rose, Rosa multiflora and bush honeysuckle,Lonicera maackii  These two common woody shrub species are actively expanding their leaves right now and are nearing full leaf expansion.  This is not the time of year to treat these species with chemicals.  Wait until the leaves have fully expanded before conducting cut stump or foliar applications.
  • Autumn olive, Elaeagnus umbellata - This species is actively expanding its leaves and starting to flower. This is not the time of year to treat this species with chemicals.  Wait until the leaves have fully expanded before conducting cut stump or foliar applications.
  • Callery (Bradford) pear, Pyrus calleryana – This species is past peak for flowering.  Many of the plants still have flowers on them but the leaves are expanding now as the flowers fade.  It is still a great time of year to find and report new populations.  Look for this species along roadsides, rights-of-way, and other open habitats.
  • Garlic mustard, Alliaria petiolata - Garlic mustard is bolting right now and starting to bloom. If a population is bolting but not flowering, it can still be treated with herbicide.  Once the population starts flowering heavily, you best option is to hand pull, bag, and remove the plants.
  • Italian arum, Arum italicum Is starting to actively grow.  New succulent leaves can be found.  This new invader is showing up in land within and adjacent to urban areas.

Central Illinois

Northern Illinois

Follow the Illinois Invasive Species Awareness blog for more phenology reports as well as other invasive species news! (Kelly Estes)

Kelly Estes

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