Green Lawns Equal Green Lakes

In town or on a lake, did you know that green lawns could also make lakes green? This ruins swimming, boating and fishing for many.

According to the Minnesota Lake Association, when fertilizer with phosphorus, a major nutrient for root growth, is applied to lawns with a high natural levels of phosphorus, the excess can run off into storm sewers and eventually carried into lakes, streams, and wetlands. Or, it can run off the lawn or lakeshore properties directly into the lake.

Phosphorous is a major pollution concern for lakes and streams because it supports the overgrowth of algae and waterweeds and can lead to oxygen depletion in the water. When one-tenth of a pound of fertilizer that contains 5 percent phosphorus washes into a lake, it can result in the growth of approximately 2.5 pounds of algae. [Facts and figures from the Minnesota Lakes Association, Paula West, 7/29/99]

Good News: most Minnesota soil is high in phosphorus, adequate for splendid lawn growth. No additional phosphorus needs to be added to our lawns. A simple inexpensive soil test can confirm this important fact. See any County Extension office for a soil test kit. In other words, if your lawn does not need fertilizer, do not use any. If the test shows that you do not need phosphorus and you still want to fertilize, use a phosphorus free fertilizer. Look for fertilizer with a middle number of (XX – 0 – XX) zero

There are other things homeowners can do to keep from polluting lakes and streams: All fertilizers, leaves and lawn clippings should be kept off the streets, driveways and other hard paved surfaces. Avoid soil erosion in all areas. Along any lakeshore, maintain a buffer of natural vegetation for at least 25 feet between the lake and the lawn. Aerate your lawn once a year in order to eliminate soil compaction.

Whether you live in town or on a lake, our lakes, streams and rivers are all part of the interrelated hydrological system, and everyone impacts water quality,” said Paula West of the Minnesota Lakes Association. Clean water is the responsibility of every human being.