Florida-friendly landscaping practices help St. Johns River

The fourteenth report on the state of the river (http://www.sjrreport.com) was recently released. It deals with issues affecting the health of the Saint John River. The report contains information that should be of interest to homeowners with residential landscapes. Nutrient levels in the tributaries leading to the river, primarily nitrogen and phosphorus, continue to be of concern.

While the solutions to these problems are often larger than what a single person can undertake, we can collectively take steps to ensure that our landscapes are not contributing to the nutrient load of the river.

Fortunately, the Florida-Friendly Landscaping (FFL) program offers several practices that we can adopt that will help all of us to protect the water quality of the river. These practices fall under four specific FFL principles: Water Efficiently; Fertilize properly; Reduce stormwater runoff; and Protect the waterfront.

Water efficiently

When you choose the right plants for your landscape, you will likely need to water them less. If you group together plants with the same watering needs and configure your zones to match, you will avoid some of the disease problems associated with poor irrigation. In addition, converting shrub beds to micro-irrigation reduces water consumption and disease problems.

Although many homeowners have automatic irrigation systems for their lawn, most are unsure of how much water they are producing and how to measure it. To make things easier, a simple lawn irrigation program should apply between ½ to ¾ of an inch of water with each watering. During hot and dry seasons (summer time) this can be done twice a week. During cooler months (Eastern Standard Time), no more than once a week. If there has been enough rainfall to achieve this amount of irrigation, no watering is necessary.

If you don’t know how many inches your sprinkler system is off, it’s time to calibrate it. This is done using the “catch can” method. By arranging several cans of tuna or cat food, you can easily determine how long it takes your system to apply ½ to ¾ of an inch of water. Measure the amount of water in the cans after running the system for 15 minutes. For example, if after 15 minutes you have ¼ “of water, it would take 30 to 45 minutes to apply the correct amount of water (½ to ¾ inch) in your irrigation system. Once you know how much of water your system puts on your lawn, you can set the timer accordingly.

Fertilize properly

There is no lawn care practice that has a greater effect on the Florida environment than fertilizing turf. If the fertilizer is improperly applied to the lawn, excess nutrients can leak out or pass through the soil and pollute our surface waters. In 2007, the state of Florida created a rule that all urban lawn fertilizer sold in the state had specific instructions on how to properly apply the fertilizer to the lawn. This makes it easier for the owner to apply the correct amount when the label on the bag is followed.

Before applying fertilizer to your landscape, do a soil test and fertilize only when necessary. Look for fertilizers that are low in nitrogen and little or no phosphorus. Timing is also important. The fertilizer should be applied when our lawn grasses are best able to absorb the nutrients and use them. This is when they are growing. One way to think about it is this: if you have to mow it often, it is because it is growing.

The University of Florida recommendations call for applying ½ pound to 1 pound of nitrogen per 1,000 square feet of turf per application of fertilizer. If you follow the directions on the lawn fertilizer bag, you are in good shape. However, Florida’s rule of lawn fertilizer allows fertilizing in late spring and summer (when the grass is actively growing) with up to 2 pounds of nitrogen per 1,000 square feet. if the fertilizer contains at least 65% of the nitrogen in a slow release form.

Reduce stormwater runoff

This principle may seem the most difficult to apply, but there are some simple recommendations that almost anyone can make. First, if you spill fertilizer on the lawn or on a sidewalk or driveway, sweep it up and put it back in the bag. In this way, the fertilizer will not be washed away in the storm water collector. If you have downspouts, make sure they run into a plant bed or permeable surface rather than a sidewalk or driveway. Finally, collecting rainwater in a cistern or rain barrel for use later in the landscape can save money on your water bill in addition to reducing stormwater runoff.

Protect the seafront

For those of us who live on any body of water, we can do our part by adopting practices that slow, filter, or eliminate runoff from reaching the water.

Maintaining the portion of your landscape adjacent to the water body as a buffer against lawns and landscaping practices can do wonders for water quality. Planting low-growing, low-maintenance native riparian vegetation in the area can help make it attractive, filter contaminants, reduce erosion, and attract native wildlife.

Providing a “maintenance free zone” at least 10 feet from the shoreline will protect water from landscape runoff by creating a distance from lawn maintenance activities. Make it attractive by setting up plants that don’t require fertilization, irrigation, or mowing. As always, make sure the area remains free from invasive alien plants such as torpedo grass.

Grass clippings and clippings are often blown or thrown into the water to get rid of them. Allowing grass clippings to stay by leaving them in place or picking up our grass clippings and composting them helps keep the nutrients in the clippings out of the water. Reducing the amount of pet waste that drains into water bodies can also reduce the levels of harmful bacteria.

Helping protect the Saint John River doesn’t mean you have to sacrifice the health of your lawn or landscape. The principles of Florida-Friendly Landscaping are based on research to provide our landscapes with what they need in a way that also helps keep our water resources healthy. For more information on other FFL principles, or additional help in creating a friendly Florida landscape, visit https://ffl.ifas.ufl.edu/.

Larry Figart is an Urban Forestry Extension Officer at the University of Florida / IFAS.

Terri S. Tomasini