By Deanne Ross, Program Specialist, Partnership for the Delaware Estuary

Published on November 14, 2007
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An abundance of lush lawns, thriving flower beds, and home-grown vegetable plots proves that landscaping and gardening are popular activities in our region. However, these countless acres are often maintained using excessive doses of fertilizer, which can pollute local waterways. To ensure your lawn doesn’t flourish at the expense of valuable natural resources, please adhere to these simple guidelines, otherwise known as “best management practices.”

Before you reach for the spreader or head to the home improvement store for commercial soil enhancers, ask yourself: What exactly does my soil need? It is easy to assume that thick grass, big flower heads, and sky-high tomato plants are the result of nutrient-rich soil. But unless you understand what your soil actually needs, efforts to improve it can waste both time and money, and they can be harmful to the environment.

Step One: Test Your Soil

Experts suggest you should test your soil at least once every three years. This information will equip you to select a fertilizer that contains just the right amount of nitrogen, phosphate and potash for your plants — no more guessing, and no more wasteful applications.

Soil testing is inexpensive and readily available throughout all three states in the Delaware Estuary. Delawareans, for example, can contact the University of Delaware’s Soil Testing Program at (302) 831-1392. Meanwhile, Pennsylvanians are welcome to call the Penn State Agricultural Analytical Services Lab at (814) 863-0841. And New Jersey residents can reach the Soil Testing Laboratory at the Rutgers New Jersey Agricultural Experiment Station by dialing (732) 932-9295.

Step Two: Follow the Directions

Once your fertilizer needs have been established by a soil test, it is imperative that proper measurement and application techniques be employed. There is only so much “food” that a blade of grass or a rose bush needs, so any fertilizer applied in excess of this amount is a waste. If these nutrients are not absorbed by plant life, they will most likely wash away during the next rainfall and end up in a local waterway.

Fertilizer runoff promotes aquatic plant growth just like on land, and the vegetation that results can literally choke waterways. This happens whenever decaying plants rob the water of oxygen that is vital for the survival of fish and other marine species. To prevent this from happening in your watershed, please follow the instructions located on the products you buy to be certain you are not over-fertilizing.

Step Three: Wait Until the Time is Right

The timing of fertilizer applications is extremely important. For lawns, fall is generally the best time to fertilize, but different plants have varying growth cycles and, therefore, require fertilizer during different seasons. Consult a lawn and garden expert if you are unfamiliar with the plants and grasses on your land. However, one timing rule remains constant: Never apply fertilizer of any kind prior to a significant rainfall. Doing so guarantees that your plants will not have adequate time to absorb the nutrients you applied, and all of your effort, as well as the money you spent, will go straight down the nearest storm drain.

Step Four: Use Natural Alternatives

“Grasscycling” and composting are both tried and true methods capable of making any lawn or garden more environmentally friendly. Grasscycling is accomplished by raising your lawnmower’s blade to cut no more than one-third the height of your grass. Ideal grass height depends on the type of grass you have, but two and a half to three inches will suit most varieties. Clippings can then be left on the ground to decompose and, ultimately, fertilize your lawn.

Similarly, composting yard waste and plant-based food scraps will help to keep nutrient-rich debris from going into landfills. The resulting “brown gold” is a nice mulch that will improve and aerate your garden’s soil. This ecologically responsible practice recycles waste materials generated in your lawn and garden while providing valuable soil enhancement, all at no cost to you or the environment.

Employing best management practices while using fertilizer is vital for keeping excessive nutrients out of area waterways. To get the most out of fertilizing and, at the same time, lessen its impact on the environment, challenge yourself to adopt these simple guidelines on your small piece of the Delaware Estuary’s watershed:

• Test soil every three years and apply products using the methods and amounts necessary according to test results and product directions
• Avoid the application of fertilizers and other chemicals prior to rainfall
• Choose plants that thrive in the soil you have, such as native plants available at many local nurseries
• Use compost and other natural fertilizing methods to improve soil quality, especially in dense ground like clay
• Remove weeds so they do not compete with neighboring plants for nutrients