It’s the height of lawn-mowing season as well as the lake recreation season. What do the two have in common? One can have a big impact on the other. Grass clippings contain phosphorus, the nutrient that feeds algae and turns lakes green. Just one bushel of grass clippings contain 0.1 pound of phosphorus. That doesn’t sound like much, but it has a big impact when it reaches a lake. It’s enough to produce up to 50 pounds of algae.
There are a few simple things you can do to prevent the phosphorus from causing problems for our lakes. When you mow the lawn, direct the grass clippings so that they stay on the lawn, not on the street, driveway, or sidewalk. Take a quick minute to sweep up any stray clippings that may have landed in the street or driveway and put them back on your lawn. This is also beneficial for you grass-leaving your clippings in place equals a single fertilize application!
If you bag grass clippings, they make a great addition to a compost pile. Just make sure that your compost pile isn’t on the edge of a stream or on the lakeshore. Phosphorus leaching from the compost pile can get into the lake or stream and produce algae.
Most cities have an ordinance prohibiting grass clippings and fertilizer from being left on the street. Check with your City to find out what ordinance they have. Next time you mow the lawn, do your part to keep grass clippings where they belong. For more information, contact the Chisago Soil and Water Conservation District at 651-674-2333.