Fall and winter are an excellent time to treat woody invasives (see the SEWISC Fall 2012 Newsletter, Volume 2 Number 3) but it is also the time to prepare sites for control during the upcoming growing season.
For some herbaceous invasive species, the winter months are opportunities to remove dead foliage that accumulated from the past year. This can be done via prescribed burns or by cutting species such as non-native cattails (Typha angustifolia and T. glauca), common reed grass (Phragmites australis), and Japanese plume grass (Miscanthus sinensis). This form of control ultimately increases the effectiveness of next season’s foliar applications by reducing the amount of dead standing vegetation that can waste herbicide through absorption during application. There are two very important points to remember.First, if you are considering using prescribed fire to remove dead vegetation check all local and state ordinances and hire a professional if you have not been trained to use this management technique. Second, if you use mowing equipment to cut the dead vegetation, always be sure to clean your mower before transferring it to another site to prevent spreading invasive species even further.
When practical, fall and winter are also good opportunities to identify populations of prolific invasive species for foliar treatments and hand-pulling management in the coming spring. Invasive species such as garlic mustard (Alliaria petiolata) and dame’s rocket (Hesperis matronalis) overwinter above ground as green plants, but they can also be identified by the previous year’s dead seed heads. Dame’s rocket, which is not as well-known as garlic mustard, is a perennial and a member of the mustard family. If snow cover is lacking, it can be identified during fall/winter by its lance-shaped leaves that form a basal rosette.
Maintaining the diversity of our native ecosystems in Southeastern Wisconsin requires year-round management of invasive species. Fall and winter seasons offer several opportunities to effectively locate and select invasive species for management in the coming growing season. Effective inventories and pre-treatment planning over the next few months will save you time and money, as you gear-up for the 2013 invasive species management campaign.