Lawn Care for a Clean Lake

What does my lawn have to do with the lake?

What can I do about it?

Ordinary storm drains on our roads, such as the one above, flow into pipes that lead directly into Kirk Lake, such as the culvert pictured below. Fertilizers and herbicides used on lawns run off into the lake with rainwater -- as in this storm drain at the north end of Kirk Lake -- that leads to algae and thicker mats of aquatic plants.

What does my lawn have to do with the lake?

Because we live in Kirk Lake's watershed, we need to be especially careful of what we do on our property and what goes into our septic tanks and storm drains. Lawn care in particular can have a big impact on the quality of Kirk Lake's water for swimming, fishing, natural habitat, and property value. Many other area lake communities have found out too late that a few simple precautions could have saved thousands of dollars in expenses and lost property value.

Much of the herbicides and fertilizers we use on our lawns ends up in Kirk Lake. That's because of something called runoff: the water that literally runs off the surface of our roads, driveways, and yards. As you might guess, virtually all of the rain and snow that lands on roads and driveways ends up as runoff. And it carries with it all of the motor oil, spilled gasoline, antifreeze, road salt and sand, and litter with it. Some of it flows directly across our property and into the lake. The rest flows into storm drains along the roads in our neighborhood, and from there it flows directly into Kirk Lake!

Now guess what percentage of stormwater runs off your lawn? 20%, 50% or 90%? Trees and shrubs are the major users of water on natural surfaces. One reason is the large surface area of their leafy mass. Leaves convert carbon dioxide -- a greenhouse gas -- into water and oxygen, and both are released through the leaves. OK, to answer our question, about 90% of all the rain and snow that fall on a lawn run off it, and wind up -- you guessed it -- in our lake! That's a bad thing because the phosphorus in lawn fertilizers is exactly what accelerates the growth of aquatic plants like Eurasian milfoil.

What Can I Do About It?

This is the simple part. Avoid the unnecessary use of chemicals on your lawn. Insecticides, herbicides (weed killers), and fertilizers get carried away by storm water runoff and wind up in the lake.

Perhaps the most important chemical to avoid is phosphorus. That's an ingredient in most fertilizers. It's only necessary in some new lawns to promote strong root growth. For most applications, it's simply not needed. To find out, you can take a sample to the local Cooperative Extension office above the Brewster Motor Vehicles office. Call for info at 845-278-6738.

Nitrogen and potash are the other two major ingredients of most fertilizers. Nitrogen keeps your lawn green. So if you're going to put down fertilizer, you can obtain phosphorus-free fertilizer at Whispering Pines Garden Center. Just ask for it at the counter!

If you use a lawn service, tell them to apply phosphorus-free fertilizer. Reputable lawn services will know what you're talking about and be happy to comply.

For more information, check out this Lawn Care web site of the Cornell Cooperative Extension. It has a separate page for each month of the year!

Using fertilizers with phosphorus is really like fertilizing the lake.

Here's another tip: Consider using native plants in your landscape design. Native plants provide food and habitat for native birds and animals.

For more information, visit the Native Plant Center at Valhalla, NY.