Action Alert: Foliar Treatments

31 July

Action Alert: Foliar Treatments

If you still have foliar treatments of non-native invasive plants on your to-do list for this summer, now is the time to get them done.  Though it may seem like fall is still a long way off, the window to treat many unwanted invaders before they set seed grows narrower by the day.  Don’t let that worry you though, we’re bringing this topic to your attention now because there is still plenty of time.

Are you unsure of the best time/method to treat a particular species?  Check out the Treatment Calendar in the Management of Invasive Plants in Southern Illinois guidebook by clicking here!

The Treatment Calendar is a very useful tool for those dealing with infestations of multiple species.  Good prioritization and planning of your treatments are important to long-term success and achieving your management goals.  For example, non-native grasses like Japanese stiltgrass (M. vimineum) and forbs such as Japanese chaff flower (A. japonica) should likely take precedence over woody species like autumn olive (E. umbellata) and Japanese honeysuckle (L. japonica) at this point in the season.  The reasoning behind this is grasses and forbs typically set seed and senesce weeks before non-native shrubs and woody vines.  Additionally, most invasive grasses and forbs can only be treated during the growing season while woody vines, shrubs and trees can be effectively managed throughout the majority of the dormant season.  

In the case of Japanese honeysuckle, wintercreeper and other semi-evergreen/evergreen vines, waiting until early fall to perform foliar applications can be advantageous.   These species can be treated after native plants have senesced, which eliminates the risk of injuring non-target species.  This is especially important since invasive vines are often intertwined with native species.  

If you have any questions or need additional guidance on how to prioritize your treatments, please contact Nathan Speagle at volunteerFRST@gmail.com or Nick Seaton at rtrcwma@gmail.com