Hi Kerri,

Gardening near wetlands is a delicate project. Our wetlands are extremely important to ecology and the survival of our native amphibians, turtles, birds, and invertebrates. 

Here is a link to some of our tipsheets about gardening near shorelines. https://www.canr.msu.edu/home_gardening/tip_sheets/smart-shorelands

I think the tipsheet Smart Gardening for Shorelands: Smart Waterfront Plants to Enhance Your Shoreline might be particularly helpful.

Here's a link to the Michigan Natural Shoreline Partnership.  https://www.shorelinepartnership.org/ It has a list of "native plants for inland lakes."

Those links should help you get started. Erick Elgin is an wetlands/shorelands expert at MSU you can read his work and contact him with questions. 

If you are trying to smother weeds with mulch, you do not have to use cardboard. Cardboard is somewhat controversial in the horticulture world. There is limited research that points towards the thought that it harms soil health. If you want to avoid cardboard, you can use a lot of mulch instead. By a lot of mulch, I mean like 10 inches deep. It breaks down surprisingly quickly and you can plant directly into it in a year. If you decide to mulch, I recommend arborist chips (if you don't mind a less uniform look). You can use the service called ChipDrop to get free woodchips delivered. 

Lindsey K. Kerr, MS, MHP (she, her, hers)
Consumer Horticulture Educator
Michigan State University Extension