Minnesota was the first state to do it way back in 2002, and other states such as Michigan and Florida have since followed them.
These states have banned the use of Phosphorus in lawn fertilizer, and many other states are considering passing a similar law.
So, what’s the big deal? Well, excess Phosphorus in water runoff can lead to a condition in lakes and waterways known as Eutrophication.
Eutrophication is basically a combination of excess aquatic growth and algae blooms, which in turn leads to depleted Oxygen levels in waterways.
Of course we all know depleted O2 levels will eventually lead to depleted aquatic life. Not a good scenario.
This is of course why detergents containing phosphates have been banned for many years in a lot of states, but many states feel that more still needs to be done to control phosphate levels, and removing it from lawn fertilizer has become a high priority.
“Haven’t you always said to use fertilizers with Phosphorus in them?” I hear you cry. Well, yes and no. We do always recommend that when you are seeding a lawn (usually in the Fall) phosphorus should be used to promote healthy and vigorous root development. At other times of the year, however, it’s not so important, and yes, in the near future our philosophy may have to change even when seeding.
However, having said that, it is relatively simple for everybody that uses lawn fertilizers to take a sensible approach to the situation.
The first thing to do is to use, whenever practical (and in most cases it is), a slow release fertilizer. Slow release fertilizer allows for a more gradual feeding of your lawn, and as such grass is more likely to use nutrients as they are needed. It is also, by it’s nature, less likely to cause runoff when using irrigation or during heavy rains.
The second simple thing? If no Phosphorus is needed, Don’t apply any. That one little thing can make a big difference when it comes to excess phosphate if we all do our part. Scientists in states that have already banned Phosphates in lawn fertilizers have found that there was plenty of phosphorus already present to support established lawns, but if you are convinced your lawn needs some then at least send your soil to be tested first.
Need more info? Here’s a nicely written article by Lake Superior Streams.
So watch in the near future for many more lawn fertilizers to carry 0% Phosphorus (it’s the middle number in a string of 3) if you haven’t seen them already, and keep in mind that established lawns will generally hold up just fine without it, and if, after reading this, you have more questions than answers, just let us know and we’ll try our best to address them.