Going organic for a greener lawn

Ah, spring! The weather warms. The robins return. People plant pansies. And the whir of lawnmowers can be heard for miles around. Yes, folks, it’s that time of year again to start caring for our lawns.

Here’s the thing: On Long Island, it’s long been en vogue to keep your lawn green with synthetic fertilizers, pesticides and herbicides, which wreak havoc on our bays.

These chemicals wash from our lawns into the South Shore’s waterways via storm drains. The fertilizers cause seaweed growth in the bays to accelerate well beyond normal levels. The seaweed breaks apart, and as it rots, it robs fish and other aquatic life of dissolved oxygen. The pesticides and herbicides poison local marine life.

According to the Neighborhood Network, a Farmingdale-based nonprofit environmental group, Long Islanders use some 10 million pounds of pesticides alone on their lawns each year. Ten million pounds!

It doesn’t have to be this way. Each year the Neighborhood Network issues a set of guidelines for keeping your lawn looking fit and trim without the use of synthetic fertilizers, herbicides and pesticides, all of which are fairly simple for homeowners to implement. If you have landscapers do your lawn, you might ask them to try some or all of these practices.

■ Mow high: Set your mower blades at 3 to 3 1/2 inches high. Don’t cut off more than one-third of the grass blade at one time. A longer blade is stronger and more resistant to pests. In spring, when grass grows fastest, you may have to cut your lawn more than once a week. And leave your clippings on the lawn. They will form a layer at ground level and slowly decompose, releasing nitrogen into the soil that will help keep your grass green.

■ Test your soil. Check its pH balance. Soil test kits and pH meters are available at garden supply stores. Keep your soil pH as close to 6.5 as possible. Grass grows best in balanced soil. Long Island soil is likely to be more acidic, which will require you to raise the pH. You can also test your soil for mineral, nutrient and organic matter. Private testing labs can do this as well as the Cornell Cooperative Extension, which can be reached at (516) 454-0900.