Lake Friendly Living: Lawn Care Tips for a Healthier Canandaigua Lake

This is the first in a series of informative articles by the CLWA Outreach and Education Committee to provide approaches to lake-friendly living. The goal of these articles is to show readers how to practice lake-friendly living that prioritizes the condition of the water and preserves the integrity of our scenic lake for decades to come. This initial article will focus on proper lawn practices to ensure the well-being of our lake.

As watershed residents, we all share responsibility for protecting the overall health of Canandaigua Lake. Since excess chemical nutrients and pollutants in our lake can contribute to harmful algal blooms (HABs), increased aquatic plant growth, and the degradation of our water quality, we can actively choose to make sensible management decisions that will have a less harmful impact on our watershed.

Since lawn chemicals and fertilizers can be carried into the lake by erosion and storm runoff, it is important to know what the three numbers on a bag for lawn fertilizer stand for. These numbers represent the amount or percentage of nitrogen, phosphorus, and potassium in the bag—also known as the N-P-K ratio. For instance, a bag labeled with “23-3-8” will contain 23% nitrogen, 3% phosphorus, and 8% potassium. So, what does each nutrient do for your lawn?

• Nitrogen helps your grass stay green by aiding in the manufacture of chlorophyll. The green chlorophyll enables plants to convert sunlight into nutrients using carbon dioxide in the air and water from the ground.
• Phosphorus, the second number, is key in developing a healthy root system for the lawn. On one hand, having strong roots in your grass will help keep your lawn green through changing weather conditions, however, on the other hand, phosphorus can also promote harmful algae blooms once it enters the lake. For that reason, it is suggested to use fertilizer that contains a moderate or higher amount of phosphorus on new lawns where the root system is not yet developed (Figure 1), but apply fertilizer with a low or 0 level once the grass is established (Figure 2). Incidentally, the New York State Department of Environmental Conservation has launched the “Look for the Zero” campaign to encourage New Yorkers to purchase phosphorus-free lawn fertilizer.
• Potassium is important to the overall plant’s health. Potassium (chemical symbol K) supports the internal processes of the plant cells that affect photosynthesis and respiration. Adding soluble potash (K2O) to the lawn helps grass withstand drought and disease during stressful hot summer months.

According to Frank Rossi, a turf specialist from Cornell, it is unnecessary to put any fertilizer on an established lawn over 10 years old unless there are bare spots and a soil test demonstrates a lack of nutrients. Also, if you do need to fertilize, the best time to do so is once in the fall. Fall fertilization promotes root growth, while spring and summer fertilization promotes top growth leading to more mowing but not necessarily healthier grass. The less we fruitlessly fertilize, the better!

In addition, residents practicing lake-friendly living are advised to (1) mow their grass no shorter than 3-5 inches, (2) leave the grass clippings on the lawn rather than blowing them into the gutter or street where they can be washed down to the lake, and (3) avoid over-fertilizing throughout the active growing seasons. Additionally, if you have a commercial landscaper cut your lawn, please tell the company not to blow grass clippings into the street.

You can join the hundreds of watershed residents already committed to following these and other lawn care principles cited on the canandaigualakeassoc.org website by taking the lake-friendly living pledge. After taking the pledge, you can choose to receive either a lawn sign or a magnetic car logo showing your allegiance to a healthier watershed environment.

Author: Doug Llewellyn, CLWA Committee Member