The lone voice of horticultural reason

Surprising Test Results

Studies at the University of Minnesota have found little difference in the level of phosphorus in storm runoff water when comparing areas using lawn fertilizers with phosphates versus areas where phosphates are not in use.

What contributes most to excessive algae growth in lakes? Grass clippings, leaves and other plant debris left in the street during rainstorms. These organic, high-phosphorus materials get washed into the street drains and wind up contaminating lakes and rivers.

Fertilizer containing phosphate does its harm when homeowners fertilize too closely to the street, don’t close the hopper when turning their drop spreaders on the street, and keep it open over any paved area. It’s a part of the problem, you bet. Applied correctly, however, lawn fertilizer is not the culprit many think it is.

If you are interested or curious about eutrophication, however, I encourage you to go this column for more information. Parts of it are pretty decent slogging.

Don Engebretson
The Renegade Gardener