Healthy lawns and gardens improve infiltration, reduce runoff and filter the water. But now, a company that for years has promoted healthy lawns by selling products containing phosphorus has changed its tune.
In March, Scotts Miracle-Gro announced that its products will be phosphorus-free by the end of 2012. The company also announced that it will use technology to develop more efficient uses of nitrogen in its lawn fertilizers.
I recently spoke with Chief Environmental Officer Rich Shank. Prior to his role at Scotts Miracle-Gro, Shank served as executive director of the Ohio Chapter of the Nature Conservancy. He is a board member of the Ohio Environmental Council and the Columbus Zoo and Aquarium. Excerpts of our conversation are below.
You recently announced that your products will be phosphorus-free by the end of 2012. What led up to this announcement?
We started down this path about five years ago. We have a big research and development center, and what we were finding in our research was that well-established lawns generally have enough phosphorus in the soils that you don’t need to add it on a regular basis. So there was little need to add it to the fertilizer.
The only place you’d need it is for people putting in new lawns or people who found, through testing their soil, that their lawns were phosphorus-deficient.
So this was 2006 , and we engaged with the states around the Chesapeake Bay area, working through the Chesapeake Bay Foundation, and came up with an agreement with them to eliminate 50 percent of the phosphorus in our products by 2009. We beat that [percentage], and now we’ve eliminated about 90 percent in our products, except for our starter products and organic products.
Generally, yeah. There’s exceptions. In lot of the new housing developments, the soil is stripped off, so the soil people get with their new home has no phosphorus. So in that case, it would be needed.
Why was phosphorus ever added to products in the first place?
It is a basic nutrient for all plants and is widely used in agriculture. You can’t grow plants without phosphorus. It’s a major component for animal life also. Actually, one of the largest sources of phosphorus into waters comes from human waste—sewage treatment plants.
Explain why phosphorus becomes such a problem in our waterways.
It’s a basic nutrient, but it becomes a problem when you get too much of it in a waterway. It leads to algae that grows everywhere. They proliferate and take off, and there’s a population explosion of algae. At first, that’s not so bad, but when they die and float to the surface or sink, the bacterial decay starts burning oxygen up. The waterways become oxygen-deficient, and that has a negative effect on all animal life.
Did you replace the phosphorus with another material, or did you just take it out, and the product is equally effective?
The latter. It’s not like laundry or dishwashing detergents. We simply removed it from the products, and it’s still just as effective .
What else are you doing to reduce the level of chemicals put into he environment through your products?
We’re doing a lot of research in how to better deliver nitrogen to the plants. Unlike phosphorus, it doesn’t really bind to the soil. It’s more water soluble. But if there’s too much nitrogen, you’re in danger of having it running off. So it’s more important in how much nitrogen is put down. You can actually cause it to be slowly released through various technologies, and we’re researching that now. You can meter out how much nitrogen is being released into your lawns and garden plants.
A lot of companies put in slow-release, which is usually coatings on the granular products. But they are not always reliable, and there’s no way to make sure it’s metered out at the right time. One thing unique about Scotts fertilizer is that we’re the only company that has all the nutrients combined in each particle.
Tell me about your research centers and what other kinds of things you’re working on.
Here in Marysville, Ohio, our campus is 730 acres. A big chunk of that is devoted to research. We’re working in the biotechnogy area. We’re developing a bio-herbicide to kill weeds that would replace the chemical herbicides. It’s derived from a fungus that’s found in nature, and we’re growing that commercially so we can grind it up and put it in our products. We’re going to be selling it in Canada in the next year.
We’re also looking at technologies to better apply product. The EdgeGuard prevents material from being spread where you don’t want it—like on the driveway or sidewalk, from where it can easily be washed into the waterways.
What is the level of understanding that the public has about these environmental issues? Do they know about the risks of phosphorus, for example?
No. We put a lot of information on our bags. Unfortunately, people don’t always read it. But we’ve been partnering with environmental groups around the country to get the word out on simple lawn procedures to minimize pollution. You’ll start to see more education in our advertising. In the Great Lakes area, we’ve conducted forums in major cities to educate people about lawn care and water pollution issues and how their homes and lawns can have a positive impact on the environment instead of a negative impact.
So what are the top three things you want customers to understand about their lawns and the environment?
- Follow the directions on the bag. Cut your grass high—3 to 4 inches. That gives you deeper roots, which hold the soil better and help filter out pollutants.
- Keep [fertilizing] materials off hard surfaces. If you get fertilizer on your driveway or sidewalk, it can run into streams. If you do get it on the driveway, sweep it onto your lawn.
- We encourage people to mulch their grass clippings with a mulching mower and put them back on the lawn, rather than bag it up and send it to the landfill. Same is true for leaves in the fall. They are full of phosphorus, so it’s good for your lawn.