Purple Loosestrife

Purple Loosestrife Update | ESLA Board Meeting – September 19, 2019

Purple Loosestrife was treated in 2018 by PLM Lake and Management Corp.    The project was started in 2017 with identifying plants on the lake, creating a spreadsheet with locations (some addresses, some GPS coordinates) and obtaining permission from the owners to chemically treat the plants.   The process spilled over into 2018, where we continued to get permission from owners, notified the public about the treatment via newspaper, then treated the plants.

We cost shared with CAKE CISMA (Charlevoix Antrim Kalkaska Emmet Cooperative Invasive Species Management Area) for the treatment, paying ½ of the cost.   Our share was $761.25.

In 2019, we wanted to determine the efficacy of our 2018 treatment and if we still had Purple Loosestrife on the lake.  Our summer intern, Sam Krause, surveyed the lake via kayak, noting GPS coordinates where Purple Loosestrife was found.   It was difficult to determine specific locations where plants were treated last year, as some notations are addresses and some are GPS coordinates.   While there is a relatively simple process to align addresses and GPS coordinates, it was not as easy as it seems.   We are still looking at merging the 2017 and 2019 data bases.

This year the majority of the plants are found along Hoiles Drive and within the Natural Area.   Some of this area was treated last year, but it is difficult to know what is new growth and what is returning growth.

There were several large areas treated last year, where property owners indicated it was 90% effective (Innis Lane – Cameron, E. Elk Lake Rd – Richardson).   There are some areas where Purple Loosestrife was not noted in 2017, but is visible this year (ie:  Palaestrum Cove, among others).

I would recommend that we treat next year.  Casey Shoaff at PLM indicated that it often takes multiple years of treatment to effectively minimize the spread of Purple Loosestrife.   We are sharing our 2019 results with Ben VanDyke at CAKE CISMA.   It is my understanding that they have applied for a grant for funding to help in the treatment of invasive species.   So, hopefully there is an opportunity for cost sharing again.

The longest part of the process is getting owner’s written permission.  This will need to be started this winter.   There will not be enough time to get written permission and carry it through to treatment in one summer season.