Making Your Lawn ‘Falmouth Friendly’ Will Help Save Our Coastal Ponds

 

 

            By now, you have probably dusted off your lawn mower. This season, as you begin your lawn maintenance, bear in mind that there are several simple, steps that you can do to help save East Falmouth’s ponds.

            The health of Great, Green, and Bournes ponds has deteriorated steadily over the past twenty-five years, and lawn fertilizers have played a role in that decline.

            Fertilizers work because they contain nitrogen, a nutrient that helps grass grow. The problem comes when  heavy concentrations of nitrogen intended for the grass leaches  through the lawns,  to the groundwater, and into the ponds. Excess nitrogen stimulates the growth of algae in the water, which in turn shades out native vegetation, destroys fish habitat, and occasionally drives oxygen out of the water column, suffocating the animals (fish and shellfish) living there.

            Fertilizers account for more than 15% of the total nitrogen entering the ponds. 

This is not as big a problem as septic waste, which contributes more than 50%. However, fertilizer loading is unique because it is something that every homeowner has the power to help reduce. As for septic waste, the town is currently reviewing ways to treat wastewater to reduce its nitrogen load.

            Obviously, the win-win situation is to maintain your lawn so that it absorbs nitrogen as efficiently as possible. This will limit the amount of fertilizer you need to use, while keeping your lawn healthy, and it will reduce the amount of nitrogen leaching out into the ponds. Many well-maintained lawns do not need any fertilizer at all. These lawns store and recycle nutrients so well that the little bit of nutrients that come in naturally from rain and the air are more than enough to keep the grass healthy. These seven steps will put you well on your way to a ‘Falmouth Friendly’ lawn:

 

1. Plant fine-leafed fescues or a fescue/perennial rye mix. Fescues are a great grass to grow

on the Cape because they are low maintenance. They tolerate shade, but will grow in the sun, are drought resistant, and require less fertilizer than other grasses. Fescues require one pound of nitrogen per 1,000 square feet/year, while many other grasses, such as Kentucky Blue Grass, requires two. Planting fescues will mean you have to use less total fertilizer, which is less of a hassle for you, and also puts less strain on the ponds. Fescues are often sold in mixes with other perennial grasses; these will also do.

 

2. Maintain 6” of soil. When it comes to soil, the deeper the better. Deep soil layers hold moisture well, and encourage grasses to grow deep roots. In turn, grasses can absorb more of the nitrogen (and other nutrients) applied to the soil.

            When you are planting a new lawn, begin on the right foot by making sure that it has at least 6” of topsoil. Existing lawns that do not have a thick soil layer should be top-dressed each year with 1-2” of a loam/compost mix every spring until you get that 6” for your grass. When you are overseeding your lawn, first apply the topdressing of loam/compost, then overseed.

 

3.  Mow at 3” and leave clippings on the lawn. Grass that is too short does not have the surface area it needs to capture sunlight and photosynthesize effectively. Letting your grass grow 3” blades will keep the photosynthetic machinery rolling, and allow the grass to develop deep roots that absorb nitrogen and other essential nutrients.

            Lawn clippings are a natural and convenient form of organic fertilizer and should be left on the lawn for the grass to enjoy. A common myth is that lawn clippings contribute to the build-up of thatch. The truth is quite the opposite: grass clippings stimulate earthworm activity that breaks down thatch.

 

4. Water infrequently. The cool season grasses typically grown on the Cape do not need much water; watering excessively can actually hurt the grass by encouraging it grow shallow roots. Watering infrequently -- only when the grass shows signs that it really needs it -- encourages grass to grow deep roots. Deep roots in turn make the grass hardy and able to withstand dry spells.

            Many deep-rooted lawns do not need to be watered at all. However, if your lawn begins to turn brown during its normal growing season (spring and fall), then it is time to water. Make sure to water deeply; a good rule of thumb is 1” per week, all at one time. One big watering a week, rather than many smaller watering sessions spread throughout the week, means that you will lose less water to evaporation. It also encourages your grass to grow deep roots, since the grass must reach down deep into the soil to get to all the available moisture.

            An easy way to make sure that your lawn gets 1” of water a week is to leave an empty tuna can out in your lawn. Tuna cans are 1” thick, so when the can is filled with water, you know your lawn has had its share for the week. If it rains in the beginning of the week, and your can is half full when it comes time to water, make sure you only add enough water to top off the can; do not add a whole other inch of water.

 

5. Have an annual soil test done to determine the pH of your soil. If you follow suggestions 1-4, you may find that your lawn is completely healthy and does not need any fertilizer. However, if your lawns does need fertilizer, the first thing to do is to check the pH of your soil. Soil pH – that is, the amount of hydrogen ions in the soil – will determine how effectively your grass can use fertilizer applied to the lawn. Grasses grow most efficiently in soils between 6.5 and 6.8 pH. You can test the pH of your soil by taking samples from 3-4 different locations in your lawn, mixing them together, and taking them to the Extension Office in Barnstable. The Master Gardeners will do the soil test there, and tell you how to correct the pH of your soil, if needed.

 

6.  When you do fertilize, fertilize in spring (April, early May) and early fall

(September). Cool seasons grasses, like the fescues commonly found on the Cape, go semi-dormant in the heat of the summer so you do not want to fertilize then. You will only be fertilizing the weeds, and the fertilizer that escapes the weeds will end up in the ponds.

            Also, make sure that you only use as much fertilizer as you need. Most fertilizers come in bags that cover 5,000 square feet. If you only have 4,000 square foot lawn, do not use the whole bag. A simple way to measure the area of your lawn is to pace off the sides of your lawn, and know that one pace is about three feet. For example, if your lawn is a rectangle roughly 15 paces by 30 paces, your total lawn area is 4050 square feet. Finally, as much as you may appreciate your driveway and sidewalks, they do not need to be fertilized. This is a case where more is definitely not better.

 

7.      Use organic fertilizers. Most fertilizers contain nitrogen in its simple, inorganic form,

which is easy for grass to take up from the soil. This is great when the fertilizer is first applied; the grasses get inundated with food. But just as you cannot eat fifty pizzas in one sitting, the grass cannot absorb all that nitrogen at once. Most of the nitrogen leaches down into the groundwater, eventually making its way out into the ponds.

            Organic fertilizers, in contrast, release nitrogen slowly, over many days, allowing the grasses to absorb much more of the total nitrogen in the fertilizer. Most local garden centers are now selling organic fertilizers. The fertilizers come under many names, such as methylene urea, ureaformaldehyde, sulfur coated urea, and IBDU. In general, if the fertilizer has 50-66% water insoluble nitrogen (WIN), you are all set.

 

With these suggestions, you will be armed with the tools you need to develop a ‘Falmouth Friendly’ lawn – one that not only looks good, but also helps preserve, and possibly restore, the health of our ponds.