Sowing the Seeds for Healthy 

Waterways:
 

How Your Gardening Choices Can 

Have a Positive Impact in Your 

Watershed
 

EPA-820-C-08-001 

June 2008 

1 
If we lived in a perfect world... 

If we lived in a perfect world.... 

2 
Chocolate cake would have no calories... 

3 
...tax credits would be given for award-winning rose gardens... 

4 
Nitrogen 

and 

Phosphorus 

pollution, 

also known 

as “Nutrient 

Pollution” 

...and everyone would know about nutrient pollution and take steps to address it. 

Unfortunately, I can’t do anything about the first and second slides, but I’m here 

today to tell you about nutrient pollution, why you should be concerned about it, and 

what you as a gardener can do to reduce nutrient pollution in your community. The 

term “nutrients” generally refers to nitrogen and phosphorus, which are the specific 

pollutants of concern that we’ll be discussing today. 

5 
Watershed
 

• A watershed is 

an area of land 

where all the 

water drains 

into a common 

body of water. 

Watersheds are 

also referred to 

as “drainage 

basins.” 

To understand nutrient pollution and how you can help reduce it, you first need to 

understand watersheds. 

A watershed is an area of land that drains into a common body of water. Within a 

watershed, each small body of water will flow into another, larger body of water, 

creating one, inter-connected system. You may have heard of the Chesapeake Bay 

Watershed or the Mississippi River Watershed – both are examples of large 

watersheds within the United States. But watersheds can also be small. There is a 

watershed for the creek or stream in your neighborhood. You are always in a 

watershed! 

6 
Developed Area 

Water runs off the land, carrying fertilizer, dirt, pet waste and 

many other pollutants with it directly into the waterway. 

The path water takes as it flows downhill 

impacts water quality. 

When precipitation falls within a watershed, the water eventually enters a waterbody 

as stormwater runoff or through groundwater recharge. In this example of a 

developed area, the rainwater washes over paved surfaces and does not have an 

opportunity to percolate through the ground. Pollutants are carried in the runoff 

water into our streams, lakes, groundwater, estuaries and oceans. Dirt, bacteria, 

nutrients, metals and pesticides are just a few of the pollutants that make their way 

into waterbodies through stormwater runoff. The focus of this presentation will be 

the nutrient pollutants. 

7 
Undeveloped Area 

The path water takes as it flows downhill 

impacts water quality. 

Water percolates through the ground slowly. 

In this example of an undeveloped area, the ground is not paved so the runoff has 

an opportunity to flow over surfaces that allow the water to percolate into the soil. 

Plants and soil act as a natural filter by absorbing some of the water and nutrients 

as well as a physical means to slow the water’s flow and allow it to saturate and 

percolate through the ground. From a water quality perspective, which is the 

preferred scenario of these two slides – the previous slide or this one? Answer – 

this slide. 

8 
Nitrogen and Phosphorus 101 

Before we talk about the problems that nutrients cause, let’s first talk about some of 

the science behind nutrients. 

9 
What are Nutrients? 

• Nutrients are elements, like nitrogen and 

phosphorus, that occur naturally in water, soil 

and air 

• Sources of nutrients 

 Decaying plant matter 

 Animal and human wastes (pet waste, septic tanks, 

waste water treatment plants) 

 Detergents 

 Fertilizer (residential, commercial, and agricultural) 

Nutrients come from several different sources. For example, decaying plant matter, 

human and animal wastes are nutrient sources. Our ecosystems depend on 

nutrients to function properly, but too much nitrogen or phosphorus can cause 

problems in waterbodies. 

Our common, everyday practices introduce nitrogen and phosphorus into the 

environment in larger quantities than would be naturally introduced. For example, 

some of the dish and laundry detergents we use every day contain phosphate, a 

form of phosphorus. The fertilizers we use on our gardens and lawns are a 

significant source of the nutrients that enter our waterways, and they are the focus 

of our discussion today. 

Note to presenter: For detailed information on detergents and phosphate, see 

Advanced Slide 11. 

10 
 

 

 

 

Advanced: Phosphorus and 

Detergents 

ADVANCED SLIDE: For audiences that request greater detail. 

Polyphosphates, a series of phosphorus compounds, can be found in detergents 

(dishwashing, laundry and commercial cleaning products). During the post-World War II 

era, two events changed the soap needs of the public: a shortage of ingredients to make 

soap and the advent of the washing machine. To meet these new needs, soap 

manufacturers added phosphates to improve the performance of detergents, particularly in 

hard water (water containing calcium and magnesium ions). Phosphate was very effective 

at improving the soap’s performance. 

Since then, concern over the impact of excessive amounts of nitrogen and phosphorus 

entering waterways has led many localities and states to institute phosphate bans in 

detergents. (Note that laundry and dish detergents are often addressed by separate pieces 

of legislation.) For example, Washington State passed a law in March 2006 limiting the 

amount of phosphates in household dishwasher detergent sold to 0.5%. There has not 

been federal action to ban the use of phosphates in detergents. I encourage you to select a 

laundry or dish detergent that is “phosphate free.” 

Note to presenter: Research your locality/state to see if there have been bans placed on phosphate 

in detergent. Visit http://water.usgs.gov/nawqa/nutrients/pubs/wri99-4007/ to download a copy of 

Review of Phosphorus Control Measures in the United States and their effects on Water Quality by

the U.S. Geological Survey. Table 1: States with Phosphate Detergent Bans will be helpful. 

11 
Nitrogen 

•	 Highly soluble in its 

common compound form, 

nitrate. 

•	 Easily washed from the 

soil by rain or irrigation. 

•	 Leached from the soil or 

absorbed by plants within 

weeks of application. 

•	 Stimulates shoot growth 

in plants. 

•	 Signs of deficiency can mimic other plant illnesses; yellowing 

leaves (with or without a reduction in size). 

Nitrogen is very soluble. This property allows it to be absorbed by plants very 

quickly – within weeks of application. However, this property also makes it a threat 

to water quality because it can be washed out of soils easily by rain or irrigation 

water. 

Fertilizers containing nitrogen promote shoot growth. Conversely, fertilizers that do 

not contain nitrogen promote the growth of flowers, fruits and roots. 

12 
 

 

 

 

 

 

Advanced: 

Nitrogen – 

How it Works 

Most plants are 

able to absorb 

nitrogen when it is 

in an ammonium 

or nitrate form 

ADVANCED SLIDE: For audiences requesting greater detail. 

The element nitrogen (N) combines with other elements to form compounds. Some common nitrogen 

compounds that you may be familiar with include ammonium (NH4

+), ammonia (NH3), nitrite (NO2-

)

and nitrate (NO3

-

). In fact, 78% of our atmosphere is composed of the inert form of nitrogen (N2). 

Plants need nitrogen to grow, but they cannot easily use every form of nitrogen listed above.

Although 78% of our atmosphere is composed of the inert form of nitrogen (N2), plants are not able to 

directly access N2 from the air. Plants are able to use the inorganic forms of nitrogen (nitrate, 

ammonium and ammonia). In the soil there are microorganisms (organisms that are visible with the

use of a microscope) that convert nitrogen into forms that are usable by plants - ammonium (NH4

+)

and nitrate (NO3

-

). 

Nitrogen “moves” among its different forms through the nitrogen cycle. To learn more about the 

nitrogen cycle, visit http://www.epa.gov/waterscience/criteria/nutrient/basic.htm to find a good

description of the nitrogen cycle. 

Nitrate is inorganic and is a commonly used form of nitrogen in fertilizers. Nitrate is very soluble in 

water and does not bind to soils. With excessive watering or runoff, nitrate is easily washed away

from the plant and enters groundwater or surface water (rivers, lakes, streams). Ammonia,

ammonium, nitrate and nitrite have the greatest impact on water quality because these forms are

directly available (or are easily converted to a directly available form) for plant/algae use. 

Total nitrogen, a summation of all of the forms of nitrogen (inorganic and organic), is often used to

determine nitrogen levels in lakes and reservoirs. 

Measurements of inorganic nitrogen forms (ammonia, ammonium, nitrite and nitrate) are often used 

to calculate nitrogen levels in rivers and streams. 

13 
Phosphorus
 

• Typically found in 

soil as an insoluble 

compound. 

• Leaches from the 

soil very slowly. 

• Deficiency appears 

first as slowed 

growth. The leaves 

will become dull and dark green or grayish green. 

In some plants, like corn and tomatoes, a hallmark of a phosphorus deficiency is 

magenta areas on the leaves. 

In a natural freshwater environment, phosphorus is found in very small quantities. 

However, in human-impacted aquatic environments, there are often larger quantities 

of the phosphorus compound, phosphate. Increased phosphate levels in aquatic 

environments are a threat to water quality because phosphate fuels the growth of 

algae and a phenomenon called “eutrophication,” which we will discuss further in 

Slide 17. 

14 
 

 

 

 

 

 

 

 

 

 

 

 

 

Advanced: 

Phosphorus – 

How it Works 

Plants absorb 

the inorganic 

form of 

phosphorus 

ADVANCED SLIDE: For audiences requesting greater detail. 

Unlike nitrogen, phosphorus does not naturally exist as a gas in the atmosphere. Phosphorus can be 

found naturally in rocks and natural phosphate deposits. Natural processes like weathering and 

erosion release phosphorus into terrestrial environments. Phosphorus is always found in a compound 

state. In nature, you would not find a P or a P2 compound. Instead, you would find phosphorus in its 

compound phosphate PO4

3- or as phosphate bound with other elements. 

Phosphorus is found in organic and inorganic forms, and it is through the phosphorus cycle that it 

moves between these forms. In its organic form, phosphorus is bound to living or dead plant/animal 

tissue or is in the by-product of a biological process such as animal excretions. Organic phosphorus 

is not available to plants for use. Phosphorus is most stable in its inorganic form, and it is in this form 

that it is usable by plants and algae. Inorganic phosphorus occurs as an orthophosphate (PO4

3- ) - (often referred to as “phosphate”) or a polyphosphate (H2PO4 or HPO4

2-). Scientists refer to this form 

of phosphorus as SRP – “Soluble Reactive Phosphorus.” 

For rivers and streams, SRP is often used to measure the phosphorus level in the waterway because 

this is the form that encourages algae growth. Total phosphorus levels are commonly used to 

measure the phosphorus levels of lakes and reservoirs – a total of the inorganic and organic sources 

of phosphorus. Why do lakes and reservoirs use total phosphorus instead of SRP to measure 

phosphorus levels? In lakes and reservoirs, phosphorus will remain in that location for a longer 

period than it would in a flowing stream or river, thus providing an opportunity for the organic forms to 

move through the phosphorus cycle in a lake or reservoir and eventually be transformed into the 

inorganic form and used by the plants/algae. 

15 
When nutrients enter a waterway, they fuel the growth of naturally occurring 

phytoplankton called algae. These photosynthetic organisms are the base of the 

aquatic food chain and produce oxygen. Nutrients fuel the algae, just as nutrients 

fuel lawns and flower beds. This picture shows an algae bloom in an Iowa lake. 

Nutrients are similar to 

chocolate – a little is good, 

but too much is a bad thing 

16 
Eutrophication: The process of excess nutrients (nitrogen and 

phosphorus) accelerating the growth of algae in a waterway, 

which often results in a decrease of oxygen in the waterbody. 

When too many nutrients enter a waterway, they fuel an “explosion” of 

phytoplankton – an occurrence that we refer to as an “algal bloom.” The process 

itself is called eutrophication. Thick algae mats block sunlight from reaching other 

underwater plants, causing the plants to die. Algae themselves have very short life 

spans. After they and other plants die, they sink to the bottom of the waterway. 

Bacteria consume oxygen while breaking down the algae, using up the limited 

oxygen resources that are available. 

As a result of the algal blooms, dissolved oxygen levels drop in the waterway, and 

aquatic organisms like fish are unable to breathe. In some cases, the algal blooms 

produce toxins that make the water unsafe for human contact. While you may not 

see algal blooms in the stream or lake nearest your home, remember that 

downstream waters could be impacted as nutrient runoff increases and reaches 

unhealthy levels. 

17 
Eutrophic 

Waterways 

These pictures are examples of the “unhealthy habitat” from the graphic in the 

previous slide. The green scum in the water is algae and is the result of excessive 

amount of nutrients entering the water. 

18 
Advanced: The Clean Water Act 

& You 

Clean Water Act 

(The Law) 

EPA administers the 

Clean Water Act 

(Federal Level) 

Stakeholder 

participation in 

the development 

of water quality 

standards 

(That’s You!) 

States create, 

enforce and 

monitor clean 

water regulations 

and report data to 

EPA 

To find your state environmental agency, visit 

www.epa.gov/epahome/state.htm 

ADVANCED SLIDE: For audiences that request greater detail. 

The goal of the Clean Water Act is to restore and maintain the chemical, physical 

and biological integrity of the nation’s waters. In order to help achieve this goal, EPA 

works with all 50 states, U.S. territories and authorized Indian tribes to set and 

enforce water quality standards for each waterbody. Water quality standards 

designate the uses for each waterbody (i.e., the human or ecological activities that 

take place in the waterbody) and assign water quality criteria - the levels of 

nutrients, chemicals, temperature, sediment and other pollutants that support those 

uses. 

Congress recognized that the public has a vested interest in the quality of our 

nation’s surface waters. Therefore, the Clean Water Act requires states, territories 

and authorized Indian tribes to hold public hearings on their water quality standards 

at least once every three years. Citizens may make recommendations to public 

officials for improvements or modifications in the standards during the public hearing 

process. 

19 
Nutrient Pollution Is a Serious Problem 

Top Causes 

of U.S. Waterbody 

Impairments 

• Mercury 

• Pathogens 

• Sediment 

• Metals 

• Nutrients 

• Waterbodies in almost 

every state and territory 

are impacted by 

nutrient pollution. 

• States have identified 

more than 10,000 

waterbody segments 

impaired by nutrients. 

http://www.epa.gov/waters/ir/ 

Many of our nation's waters, including streams, rivers, wetlands, estuaries and 

coastal waters, are affected by nitrogen and phosphorus pollution. Every two years, 

states are required by Clean Water Act sections 305(b) and 303(d) to report which 

waterbodies within the state do not meet state-set water quality standards. 

For information about the condition of surface waters in your state, visit 

http://www.epa.gov/waters/ir/. 

20 
 

 

 

 

 

 

 

 

Advanced: Nutrient Criteria for 

Rivers and Streams 

• TN, HI, American Samoa, Guam, Cherokee Nation: Approved 

nutrient parameters 

• DC, FL, OK, NV: Approved parameters for N, P and chlorophyll 

• MA, ME, VT, KY, MI, WI: Are developing criteria for their parameters 

• Thirty-four states are collecting data for their parameters and waters 

• WV, ND, SD, WY, AK, ID, OR, WA: Are just beginning the process 

Information is current as of May 14, 2007 

Go to www.epa.gov/waterscience/criteria/nutrient/strategy/status.html 

to find more updated information or contact your state environmental agency 

by visiting www.epa.gov/epahome/state/htm. 

ADVANCED SLIDE: For audiences that request greater detail. 

Definitions: 

Criteria – A minimum or maximum level of a water quality parameter that protects a given use in a

waterbody. For example, a dissolved oxygen criteria may state that a waterway should contain five

parts per million (ppm) of dissolved oxygen or more. 

Parameter – The specific component of water quality that is being tested. For example, a water

scientist would conduct a test to determine the specific level of the parameter pH or the parameter

nitrogen in the water. 

Because each state generates criteria specific to their waterways, there is some variation across the 

country with regard to state’s water quality standards and where each state is in their legislative

process of adopting new standards - as shown by this slide. To protect against excess nutrients in

surface waters, EPA recommends that states create standards for nitrogen, phosphorus, chlorophyll 

a (a measure of the abundance of algae in the water) and transparency (the clarity of the water). As 

you can see, five states and U.S. territories have completed this task for rivers and streams in their

jurisdictions. Some states are not as far along with this process. They may have criteria for some of

the suggested parameters or are in the process of developing criteria or are monitoring their

waterways to collect data to help develop the criteria. To get an update on your state’s nutrient water

quality criteria development progress, visit the EPA Web site listed on the slide or contact your state

environmental agency. 

Note to presenter: To determine the status of nutrient criteria development in your state, check

www.epa.gov/waterscience/criteria/nutrient/strategy/status.html. 

21 
Nutrients that Enter Our Waters 

Come from a Variety of Sources 

I mentioned earlier that nutrients come from a variety of sources such as pet 

wastes, septic tanks and fertilizer. Let’s look at data from specific regions of the 

country to see what sources of nutrients are plaguing certain watersheds. Although 

your region may not be represented in this presentation, these examples are 

somewhat representative of what is happening around the country. As we go 

through them, feel free to share your thoughts on other regions of the country where 

source contributions may be quite different. 

Note to presenter: Try to find region-specific information for your area for 

comparison. 

22 
 

Kinnickinnic River, Wisconsin 

As we saw with the development of nutrient criteria, there is some variation across 

the country with the progress being made toward addressing our nutrient problems. 

Many localities have begun determining the sources of the nutrients that are 

entering their waterways – the first step in creating a plan to address the problem. 

Pictured here are pie charts depicting the total nitrogen and phosphorus loads in the 

Kinnickinnic River Watershed, located just south of Milwaukee in Wisconsin. Note 

that the majority of the nutrients entering this watershed come from “Nonpoint 

Urban Sources.” Nonpoint urban sources include runoff from land uses such as 

residential, industrial, commercial and so on. 

23 
Sarasota, Florida 

Note: Data taken from Sarasota Bay Estuary Program. 

“State of the Bay 2006” 

Sarasota, FL is south of Tampa and north of Fort Myers on the Gulf of Mexico 

Coast. As with the Wisconsin example on the previous slide, you’ll note that in the 

Sarasota Bay’s watershed, stormwater runoff is the primary source of nitrogen. For 

this locality’s example, the contribution of nitrogen from stormwater runoff comes 

from sources such as fertilizers and pet wastes that are washed off of the ground 

and into storm drains that lead to local waterbodies. 

24 
The Chesapeake Bay 

Note: Data taken from the Chesapeake Bay Program www.chesapeakebay.net 

The restoration process for the Chesapeake Bay in the Mid-Atlantic portion of the 

country is one of the oldest, national-scale efforts to restore a watershed. Because 

of federal, state and local resources that have been appropriated to the 

Chesapeake Bay, the level of detailed data is greater and the identified nutrient 

sources impacting this watershed are more specific than in our Sarasota and 

Kinnickinnic examples. Ideally, this amount of data is what we would like to see for 

all localities. It not only helps identify the source of problems, but also helps states 

and EPA track improvements in water quality. 

Where does the nitrogen come from that is deposited from the atmosphere? 

Sources such as vehicles, electric utilities, industry, livestock and fertilized soil. 

What is of particular interest to us on this pie chart is the slice representing chemical 

fertilizer. Approximately 73 million pounds* or 26% of the total nitrogen load to the 

Bay in 2005 was due to fertilizer from agricultural and urban/suburban areas in the 

Bay watershed. Of this total, approximately 44 million pounds came from 

agricultural lands and 29 million pounds came from urban/suburban lands. 

*Numbers were based on long-term average hydrology simulations. 

25 
Chesapeake Bay - Phosphorus 

Note: Data taken from the Chesapeake Bay Program www.chesapeakebay.net 

Note here that again, urban and suburban sources of phosphorus are a significant 

portion of the pie chart. You might be wondering what is meant by the term “legacy 

sediment in stream channels.” When this particular watershed was originally settled 

in the 1700s and 1800s, large swaths of trees were cut down to make room for 

settlers. This deforestation and later land-clearing practices resulted in a significant 

amount of erosion. Today, sediment resulting from land disturbances in years past 

is still being flushed through the watershed and is making its way to the Bay. But 

what does sediment have to do with phosphorus? 

26 
 

Soil Erosion Also Carries Nutrients to Waterways
 

Erosion not 

only washes 

away 

valuable 

soil but 

carries 

pollutants, 

including 

phosphorus, 

into 

waterways. 

In addition to being washed directly from lawns and gardens, phosphorus is carried 

by sediment that is washed into our stormdrains and waterways. Earlier in the 

presentation, we discussed how phosphorus is not very soluble. In fact, it readily 

binds to soil. When sediment washes off of the land and into our waterways, it 

carries phosphorus with it. 

By itself, sediment can smother bottom-dwelling plants and animals, such as 

macroinvertebrates, oysters and clams, and decrease the water’s transparency, 

making the water cloudy so less light is available for underwater vegetation to grow 

and produce oxygen. Sediment-carrying nutrients presents an even greater 

problem... 

27 
The Chesapeake Bay – Sediment 

Note: Data taken from the Chesapeake Bay Program www.chesapeakebay.net 

An estimated 18% of sediment loads entering the Bay comes from urban and 

suburban areas. Sediment erosion occurs in an urban/suburban setting when soil is 

exposed during a precipitation event or during times of high wind. The sediment is 

washed or blown down stormdrains or directly into a nearby waterway. Common 

areas where this occurs include construction sites, eroded non-tidal streambanks 

and spots in lawns and landscapes that are not vegetated. 

Remember! Erosion is a natural process, hence the portion of the pie chart that 

represents natural/forest sources. But when erosion takes place at an accelerated 

pace and from unnatural causes (which represents 80% of this chart), there is a 

negative impact on water quality. 

28 
Summary 

Too much 

fertilizer 

is applied 

Nutrients and 

sediment 

reach 

waterway 

Algal blooms 

and other 

water quality 

problems 

result 

This slide provides a simple summary of the path of nutrients. The choices we 

make on land have a direct impact on water quality. When water runs off our 

property, nitrogen and phosphorus are carried away by the water. Algal growth is 

fueled by the addition of nitrogen and phosphorus. The waterway’s health declines 

and the waterway becomes “impaired.” So what can we do to stop this process from 

continuing? 

29 
So What Can You do About 

Nutrient Pollution?
 

It’s simple! Follow these tips: 

1.	 Test Your Soil 

2.	 Apply Fertilizer Sparingly 

3.	 Adopt Sustainable Lawn Care Practices 

4.	 Improve Soil Drainage 

5.	 Use Water Wisely 

6.	 Plant Natives 

7.	 Plant Lawn Alternatives 

8.	 Get Involved in Your 

State’s Water Quality 

Standards! 

As a gardener, you have the potential to contribute to nutrient pollution, but you also 

have the power to help prevent it. There are several easy things you can do to 

reduce nutrient pollution from your yards and gardens. The next several slides will 

take you through each of these recommendations. 

30 
60% of Tennessee residents use fertilizer 

regularly. Only 25% of those who report 

using fertilizer also used soil tests. 

 

 

 

 

 

Tip#1: Test Your Soil First! 

• Soil test results provide specific nutrient levels and 

the pH of the soil. 

• They allow you to make 

an informed fertilizer selection. 

• Where do you get a test kit? 

 Over-the-Counter kits are 

available at garden centers
 

 Tests run by skilled labs 

are available from local 

extension offices
 

Soil testing is a useful tool that can help ensure the efficient use of fertilizers. Soil tests provide a 

means for assessing the fertility status of a soil. They measure the quantity of a nutrient that is

extractable from the soil by plants. 

Soil testing can provide information about how to enhance the beauty and productivity of a lawn, 

landscape planting or vegetable garden. By knowing the plant nutrition needs of your lawn and

gardens, you can choose the correct fertilizer to meet the needs of your plants, prevent the overapplication of nutrients and help protect your local waterways. 

Soil test kits are available at most garden supply stores. These easy-to-use kits contain chemical 

reagents for the on-the-spot determination of pH, nitrogen, phosphorous and potassium. Small test

tubes are filled with soil and mixing indicator dye into the soil. The resulting color is matched to a 

color chart to determine the levels of nutrients and pH in the soil. Keep in mind that some soil test kits

are easier to use than others and that these kits don’t always provide the most accurate results 

because of the sometimes complex relationships that occur between sediment and nutrients that we 

discussed earlier. 

The best way to get an accurate soil test analysis is to have it sent to a laboratory for testing. Many

state or county cooperative extension offices provide soil testing for free or for a nominal fee. These 

same offices have horticultural experts to consult regarding the soil types in your area and the needs 

of specific plants. 

Note to presenter: Locate the nearest cooperative extension office that conducts soil tests by

visiting http://www.csrees.usda.gov/Extension/. 

31 
Tip#2: Use Fertilizer Sparingly 

• Fertilizer Basics 

 Fertilizer has three numbers 

on the label 

• 1st number: % nitrogen 

• 2nd number: % phosphorus 

(or its compound phosphate) 

• 3rd number: % potassium 

(also listed as potash) 

• Your fertilizer selection 

should address the needs 

of your soil based on the 

results of the soil test. 

Fertilizers supplement the nutrients that are already naturally existing in the soil. 

Plants absorb nutrients that are essential for their growth through their roots. While 

many different nutrients are required for healthy plants, nitrogen, phosphorus and 

potassium are considered the three primary nutrients. 

Potassium regulates numerous reactions that take place in plants and is associated 

with durability and disease resistance. Potassium plays a role in activating enzymes 

and photosynthesis, opening and closing stoma (which regulates water and air 

loss), sugar, water and nutrient transport within the plant, and protein and starch 

synthesis. A deficiency of potassium is marked by the yellowing of the outer 

margins of leaves, particularly the older leaves, but the signs of deficiency can differ 

among plant species. Potassium has not been shown to have a detrimental effect 

on the environment. 

32 

Nitrogen 

Phosphate 

Potassium 
Fertilizer Application Best Practices
 

•	 Read the instructions – apply the 

correct amount at the correct time 

of year – more is NOT better. 

•	 Match the fertilizer to your plants – 

the appropriate fertilizer for your roses 

might not be the correct one for your 

lawn. 

•	 If there is a forecasted weather event, 

like high winds or rain, fertilize after the 

weather event. 

•	 Spread fertilizer only to vegetated areas. 

Don’t fertilize sidewalks, driveways and 

other paved surfaces! Sweep up spills. 

•	 Leave an unfertilized buffer between a 

waterway and where fertilizer is applied. 

Each of the bullets on this slide are steps that you can take to eliminate fertilizer 

waste. You will save money by only using the amount that is necessary and will 

help protect your waterways from nutrient-contaminated runoff. 

Contact your local cooperative extension agent or Master Gardener to learn more 

about which fertilizers are recommended for your area. 

33 
Tip#3: Adopt 

Sustainable 

Lawn Care Practices 

Select the grass that fits your geographic region 

Cool Season 

Zone 

– Fertilize in 

the Fall 

Warm Season Zone 

– Fertilize in the Late 

Spring/Early

Summer 

Transition Zone 

Examples: Fescue, 

Bluegrass, 

Ryegrass 

Zoysia, Bermuda Warm or cool season 

grasses can be 

selected 

Ideal Height 2” – 4” 1⁄2” – 1” 

Typical 

Geographic 

Region 

Throughout 

Northern 

United States 

Southern United 

States: Texas to North 

Carolina and as far 

north as Tennessee 

Between the Cool 

and Warm zones, 

running east to west 

– Virginia to 

Southern California 

It is important to make the right choices when planning and caring for a lawn. 

Choosing the wrong type of grass, over-watering, over-fertilization and cutting a 

lawn too short are all practices that can have a negative impact waterway health. 

To help reduce the amount of fertilizer you use, plant grass that grows the best for 

your geographic region. 

Note to presenter: Determine which zone you live in and highlight that column 

during your presentation. If possible, make specific recommendations for where you 

live. 

34 
 

 

 

Other Lawn Care Tips 

• Compost grass clippings and leaves. 

• Aerate your lawn. 

• Use a bagless lawn mower and allow the 

lawn and leaf clippings to decompose on 

the lawn. 

• Never apply fertilizer, pesticides or 

herbicides within 10 feet of a stream, 

creek or other waterway. 

• When mowing, only remove the top third 

of the grass height. 

• Plant buffer strips along drainage ditches 

and waterways. 

• Use mulch to reduce the need for 

fertilizers. 

“If grass were harvested as a 

crop, it would represent one of 

the United States’ largest 

commodities (USDA, 1992).” 

One of the themes of this presentation is that too much of a good thing is harmful. While 

grass and leaf debris are natural, when they enter our waterways in large quantities, the 

resulting surplus of nutrients degrades the water quality. Keep your leaves and grass 

clippings out of the gutters and street. 

Use of a bagless lawn mover allows fine leaf and grass clippings to settle in your lawn and 

act as a natural fertilizer. 

If you must use pesticides and herbicides, contact your local cooperative extension agent to 

assist you in selecting the most environmentally friendly option. Visit 

http://www.csrees.usda.gov/Extension/ to find your local cooperative extension agent. 

Aerate your lawn! You will help the water penetrate the ground and reach the roots of the 

grass. Plant buffer strips to drastically reduce polluted runoff from your property. The 

additional vegetation in the buffer strip will slow down the runoff, allow the water to soak 

into the ground and keep pollutants from entering your waterways. 

Want to Learn More? Contact your local cooperative extension agent or Master Gardeners. 

Florida’s Lawn Care and Irrigation Web site is also very helpfulhttp://livinggreen.ifas.ufl.edu/water/lawn_care_and_irrigation.html 

35 
 

 

 

 

 

 

 

 

 

 

Tip #4: Improve Soil Drainage
 

• Evaluate the amount of impervious surface on your 

property. Can it be reduced? 

• A well-drained soil creates a good environment for grass, 

plants and trees to set deep roots and take advantage of 

deep water and nutrients. 

One way to stop water from running off your land is to decrease the amount of impervious surfaces 

on your property. Impervious surfaces, like roofs, driveways, patios (some types) and sidewalks, are 

surfaces that water cannot penetrate. Water flows over these surfaces, carrying with it any 

substances that are on the ground. Today there are many alternatives to using impervious surfaces. 

Many agencies and organizations are using the term “low impact development” (LID) to refer to these 

environmentally friendly alternatives for our homes and cities. Roof gardens, pervious pavers and 

permeable concrete are a few LID options for how we develop our properties and urban areas. To 

learn more about LID, visit: 

•EPA’s Repository of Low Impact Development Fact Sheets: 

http://www.epa.gov/owow/nps/lid/lidlit.html 

•Low Impact Development Practices Implemented at EPA Headquarters – a Fact Sheet: 

http://www.lowimpactdevelopment.org/lid%20articles/lid%20fact%20sheet%20050207.pdf 

•Urban Design Tools – Low Impact Development: http://www.lid-stormwater.net/lid_techniques.htm 

•EPA’s Green Infrastructure Web site – http://www.epa.gov/npdes/greeninfrastructure 

Balanced growth in your plants is encouraged by well-drained soil. Deep roots make for healthy, 

steady growth with reduced fertilization and irrigation needs. It also reduces the need for pruning 

maintenance as well as disease and pest pressures. In the picture, the root system on the far left is 

ideal and a slow, deep soaking of your plants will encourage this type of root growth. The picture on 

the far right is the least desirable option and will cause your plants to be dependent on the first few 

inches of soil and your watering practices for moisture. 

36 
Improve Soil Drainage with 

Composted Material or Mulch
 

• The proper soil alterations 

can help a soil drain faster 

or slower and increase its 

nutrient content. 

• Well-composted organic 

material acts as a source 

of slow release nutrients 

for plants. 

• Thoroughly blend or till 

compost into the soil. 

You can improve soil drainage with composted materials or mulch. These 

alterations help plants absorb nutrients at the correct rate. Well-drained soil 

generally absorbs 1⁄2 an inch of water or more per hour. 

Remember that soils can be too well-drained, such as a sandy soil. Adding 

composted material can address this concern as well. 

37 
What Not to Do What Not to Do

Tip#5: Use Water Wisely 

• Use water in moderation (if at all). 

• Water only the places that require 

moisture. 

• Use drip systems or micro-emitters to 

help keep water and fertilizers in 

place. 

• Water plants “deeply”—encouraging 

the roots to grow deeper and 

lessening the need for future 

watering. 

• Water in the early morning or 

evening and skip watering on windy 

days. 

• Install a rain barrel to use in watering 

your plants. 

As excess water runs into the street and down storm drains (as shown in the picture 

above), it washes away sediment and nutrients with it. By watering minimally (if at 

all) and only on surfaces that allow the water to percolate through, the gardener is 

preventing sediment and nutrient pollution. 

When too much water is used, it has to go somewhere. Often that somewhere is 

your nearest stormdrain or waterway in the form of runoff. Adopt water usage 

practices that minimize, and ideally eliminate, runoff from your property. 

Why not water on windy days? The wind will encourage the water to evaporate, 

thus causing water to be wasted and not reach the roots of your plants. 

38 
Using Water Wisely 

• Recycle household water for watering 

plants instead of pouring it down 

the drain. 

For example: 

 Old water in a dog/cat bowl 

 Left over water in a glass 

 Water used to boil vegetables and wash 

fruits and vegetables 

Want More Tips for Water Conservation? Visit 

• EPA Water Sense: www.epa.gov/WaterSense 

• EPA Brochure Make Your Home the Solution 

to Stormwater Pollution: 

www.epa.gov/npdes/pubs/solution_to_pollution.pdf 

• Rain Garden and Rain Barrel Information – 

www.stormwaterauthority.org/library/view_article.aspx?id=944 

Instead of sending your water down the drain and to a wastewater treatment plant 

or septic field, think about ways that it can be used around your home and garden! 

Recycle your water! 

39 
Did you 

know that English Ivy is 

a non-native plant? 

It spreads aggressively, 

killing native plants and 

trees by covering and 

shading them out. 

English ivy also hosts 

bacterial leaf scorch, a 

plant pathogen that 

spreads to native elms, 

oaks, and maples. 

Tip#6: Plant Natives 

• Reflect the local, natural history 

• Provide food and habitat for local and 

migratory animals 

• Reduce the need for chemical pesticides, 

herbicides and fertilizer 

• Are adapted to local climate and soil types 

Exotic plants that lack environmental 

stressors, like disease or pests, will outcompete native plants and will decrease 

the area’s biodiversity.
 

A native plant naturally occurs in a specific region without assistance from people. 

In addition to reflecting the local natural history of the area, native plants reduce the 

need for pesticides, herbicides and fertilizer because they are already well-adapted 

to the climate and soils of the area. 

Exotic plants are those that have been introduced from a different region through 

human intervention. For example, Tree-of-heaven and multiflora rose are native to 

Asia and garlic mustard is native to Europe. All three species have been introduced 

to the United States where they have had a negative impact on the local 

ecosystems. 

To learn more about which plant species are native to your area, visit:
 

National Park Service’s Weeds Gone Wild, Alien Plant Invaders of Natural Areas: 

http://www.nps.gov/plants/alien/
 

U.S. Department of Agriculture, Natural Resources Conservation Service - Plants 

Database: http://plants.usda.gov/ 

40 
Tip #7: Plant Lawn Alternatives 

Create a Rain Garden or Bayscape 

Located near 

downspouts and 

other drainage 

areas where water 

collects following 

a storm 

Located in dry or 

moist areas 

Utilizes native plants 

Reduces stormwater runoff and allows 

water to slowly percolate through the 

soil; allows up to 30% more water to 

percolate through the soil 

Bayscaping Rain Garden 

Addresses erosion, poor soil, steep slope 

or poor drainage problems 

Reduces time and expense for mowing, 

watering, fertilizing and maintaining 

Visually more interesting than a lawn 

Sample Bayscape 

Bayscapes and Rain Gardens utilize native plants – plants that are naturally from 

your region and are adapted to the climate. 

When designing your landscape, consider replacing or augmenting your grassed 

areas with native plants. More likely than not, the native plants that you will have to 

choose from will be taller and have a deeper, more extensive root system than a 

lawn. The deeper root system will allow water to penetrate deeper through the soil 

as it follows the path of the roots underground. These plants will absorb more 

nutrients and water, resulting in less runoff. Native plants are also adapted to your 

climate, reducing the need for supplemental watering, fertilizing and mowing. 

Depending on your selection of native plants, they can attract local wildlife such as 

butterflies or birds, too! 

Bayscaping is also referred to as "beneficial landscaping" and "conservation 

landscaping.” 

41 
 

The fact that rain gardens are sunk into the ground separates them 

from other forms of natural landscaping. 

 

 

 

 

 

 

Getting Your Rain Garden Started:
 

• Don’t forget the soil

test! 

• Position the garden

downhill of the water 

source. 

• Remember – it is a 

garden, not a pool. 

• Make it a 

community event! 

• Post a sign

explaining your

rain garden. 

Whether you are creating a bayscape or a rain garden, each should be carefully designed and take into 

consideration the slope and soil composition, among other aspects, of your property. Before you start 

planting, do a little research and planning. Draw a map of your property. Where would be the best location 

for the garden? What type of soil do you have? Does the soil need to be augmented? Is the location for 

the garden in full or partial sun and which native plants thrive best in those conditions in your area? These 

are a few of the questions that you should consider when designing your rain garden. 

Make note of the sources of water on your property when planning a rain garden and work with (not 

against) the flow of water. A properly functioning rain garden will hold water for a few hours following a 

normal storm event, not a few days. 

You don’t have to create your rain garden alone! Ask friends and neighbors to help install your rain 

garden. You are not only making less work for you, but providing others with a hands-on education in rain 

gardens! And don’t forget to offer to help your neighbors when it comes time for them to create their own 

rain garden. 

Many of your neighbors may not be familiar with rain gardens or other natural forms of landscape. If your 

garden is visible to the public, consider posting a sign describing what a rain garden is and how it benefits 

your watershed and its water quality! Take pictures and show off your work to your local garden club 

chapter! 

42 
Tip #8: Get Involved in Your 

State’s Water Quality Standards!
 • Visit EPA’s Surf Your Watershed Web site 

http://cfpub.epa.gov/surf/locate/index.cfm 

Once you locate your watershed, click on Citizen-based 

Groups in Your Watershed to learn about local ways that 

you can get involved in water monitoring and other 

watershed-related activities. 

There are so many different ways that you can become involved with water quality 

in your community! 

•	 Participate in cleanup activities in your neighborhood. 

•	 Write or call your elected representatives to inform them about your concerns 

and encourage legislation to protect water resources. 

•	 Get involved in local planning and zoning decisions and encourage your local 

officials to develop erosion and sediment control ordinances. 

•	 Promote environmental education. Help educate people in your community 

about ways in which they can help protect water quality. Get your community 

groups involved. 

43 
Get Involved in Your State’s Water 

Quality Standards 

• Participate in the public review process of 

your state’s water quality standards 

http://www.epa.gov/waterscience/standards 

To learn about your state’s water quality standards and when the next opportunity 

will be to participate in the public review process, visit this site. Be sure to visit the 

following sections of this page: 

•Basic Information – Provides background information on water quality standards 

and their purpose in water quality protection 

•Where You Live – Provides links to EPA Regional pages pertaining to water quality 

standards 

•State, Tribal and Territorial Standards – Provides links to water quality standard 

documents for each of the states, tribes and territories 

44 
Synopsis 

1.	 When present in the proper quantities, 

nutrients and algae are important 

components of an ecosystem. 

In excessive amounts, the ecosystem 

becomes out of balance. 

2.	 Your choice of plants impacts the need 

for supplemental watering 

and fertilization. 

3.	 Keeping soil covered with plants 

or mulch is an important step 

to protecting water quality. 

4.	 Soil test results will tell you the type of fertilizer that is 

needed. Always follow the fertilizer application directions. 

5.	 Spread the word to your friends and neighbors! 

45 
 –

To Learn More, Visit: 

Environmentally Friendly Landscaping: 

• Backyard Conservation (Includes Fact Sheets): 

http://www.nrcs.usda.gov/feature/backyard 

• EPA WaterSense Landscape Irrigation Services: 

http://www.epa.gov/WaterSense/pp/irrprof.htm 

• Florida Friendly Landscaping: http://www.floridayards.org/ 

• Home and Garden Tips: 

http://www.nrcs.usda.gov/feature/highlights/homegarden/lawn.html 

EPA Water Quality Standards and How to Get Involved: 

• EPA – Locate Your State Environmental Agency: 

http://www.epa.gov/epahome/state.htm 

• EPA – Water Quality Standards for Nitrogen and Phosphorus Pollution: 

http://www.epa.gov/waterscience/criteria/nutrient/ 

• EPA – Water Quality Standards Online Academy: 

http://www.epa.gov/waterscience/standards/academy 

• EPA National Nutrient Strategy Current Status: 

http://www.epa.gov/waterscience/criteria/nutrient/strategy/status.html 

46 
-

 –

 

More Places to Visit:
 

Rain Gardens: 

• The New Jersey Native Plant Society’s Rain Garden Manual: 

http://www.npsnj.org/rain_garden_home.htm 

• Wisconsin Department of Natural Resources – A How To Manual for Homeowners: 

http://www.dnr.state.wi.us/org/water/wm/dsfm/shore/documents/rgmanual.pdf 

• Virginia Department of Forestry Rain Gardens (includes Rain Garden Technical Guides): 

http://www.dof.virginia.gov/rfb/rain-gardens.shtml 

• 10,000 Rain Gardens: http://www.rainkc.com 

47