DATCP: Buying fertilizer for your lawn? Be aware of new restrictions on turf fertilizer

Contact: Jane Larson (608) 224-5005

MADISON–Beginning April 1, Wisconsin residents can no longer apply turf fertilizer that contains phosphorus to their lawns except in limited circumstances. The restriction also applies to professional lawn and landscape businesses, golf courses and municipalities. The intent of the law is to protect Wisconsin’s lakes, streams and rivers from phosphorus runoff.

Fertilizer products carry three numbers that indicate the amount of nitrogen, phosphorous and potash in the product, commonly referred to as N-P-K. The middle number which represents the amount of phosphorus “P,” should be zero.

“The new law makes it illegal for Wisconsin retailers to display turf fertilizer that is labeled as containing phosphorus or available phosphate,” explained Charlene Khazae, fertilizer program manager, Wisconsin Department of Agriculture, Trade and Consumer Protection.

Homeowners would still be allowed to apply fertilizer that is labeled as containing phosphorus if they are putting in a new lawn or if a soil test done by a soil testing laboratory shows that the lawn is deficient in phosphorus. The tests must be performed no more than three years prior to applying phosphorus fertilizer.

Finding lawn fertilizer with phosphorus will be more difficult. Retailers that sell lawn fertilizer such as hardware stores, garden centers and discount stores will not be able to display lawn fertilizer that is labeled as containing phosphorus. Retailers can post a sign that indicates fertilizer with phosphorus is available upon request.

Homeowners or residents who are seeding a new lawn or laying sod can apply turf fertilizer that contains phosphorus during the growing season when the grass is being established, or if soil tests show that the lawn is deficient in P. However, that type of fertilizer won’t be on display in the store so you will have to ask if it is available, reminds Khazae.

Fertilizer that contains phosphorus can still be used in agricultural production, pastures and home gardens.

Similar restrictions already exist in places such as Dane County, some counties in Michigan and Florida and in the state of Minnesota.

The new law also adds some additional restrictions to all types of turf fertilizer, no matter if it contains phosphorus or not:

* Fertilizer cannot be applied to frozen ground. Generally if you can dig down six to eight inches, the ground is unfrozen.

* Fertilizer cannot be applied to impervious surfaces like driveways or sidewalks, even if the application is unintentional.

“If you get fertilizer granules on your driveway or sidewalk, sweep or hose them into the grass, or sweep up the granules and put them back in the bag or in the trash. Do not hose or sweep the fertilizer granules into the street or into storm drains,” Khazae said.

Keeping fertilizer off hard surfaces also applies to fertilizer products applied by professional lawn and landscape businesses.

What if you have fertilizer leftover from last season?

“After April 1, that old fertilizer is not legal to use unless you meet those exceptions. You could dispose of it in the trash, or take it to a local Clean Sweep collection particularly if it contains a pesticide like those found in “weed and feed” products,” Khazae said.

For more information about the turf fertilizer law, visit http://www.datcp.state.wi.us and search on “turf fertilizer” or contact Charlene Khazae, 608-224-4541.