Caring For Local Wetlands And What Not To Do With Your Leaves

Fourteen years ago, my husband and I bought our first home on a quiet dirt road with thick oak and maple woods in the back yard and a sprawling wetland across the street. I was in graduate school at the time, studying natural resources science and management, and excited to live in a home surrounded by nature with room for our brand new dog to run. Soon, autumn arrived and leaves from the trees began to fall in masses, blanketing our lawn. At first, we tried raking and bagging the leaves, but we soon grew frustrated and weary. Surely there was an easier way?

Eventually, we began piling the leaves into a wheelbarrow and rolling them across the road to the wetland, dumping them there to decompose naturally over time. I was a natural science major, and yet, never once did it occur to me that our actions might be harming the wetland.

Wetlands are sensitive resources that provide habitat and filter water pollution. Dumping leaves into wetlands can smother native plants and cause algae blooms in the spring.

Two years later, I began my current job working with local cities and watershed districts and quickly learned that leaves and grass clippings are one of the biggest sources of phosphorus for urban lakes and wetlands. This phosphorus causes excess algae growth and contributes to unhealthy lakes with murky water that looks gross and can sometimes even be dangerous. Lakes and wetlands in Minnesota get a pulse of phosphorus during the late fall and early spring, as leaves in the street break down and release nutrients into rainwater and snowmelt flowing into the storm drains and ditches. They also fall victim to well-meaning people like me that dump leaves into wetlands, lakeside buffers, and wooded ravines, not realizing how quickly those leaves can overwhelm aquatic ecosystems. As wetlands become over-saturated with nutrients, they also lose their ability to filter water traveling to lakes and rivers and sometimes even become a source of pollution for those downstream waterbodies.

So, what should you do with your fall leaves and other yard waste? Here are a few suggestions:

  • Got a small yard? Rake and bag leaves from your yard and sidewalk. Dispose of the leaves by composting them in your yard or bagging them for curbside pick-up.
  • Got a big yard? Rake areas directly under trees and then use your mower to mulch the rest of the leaves into the grass. Mowing is less time intensive than raking and the shredded leaves act as a natural fertilizer for your lawn. In fact, research from the University of Minnesota shows that if you mulch grass clippings and leaves into your lawn throughout the year, you will only need to fertilize once a year at most. Be sure to aim the blower away from the street and driveway or, in heavily blanketed areas, bag and compost the mulched leaves.
  • Got a street? Rake and bag the leaves and debris settled against the curb and in the street in front of your home, as well as any debris covering the nearest storm drain inlet.

Whichever strategy you employ, remember to keep your leaves and yard waste out of the regular garbage, and never dump them into wetlands or buffer areas. Both practices are actually illegal!