Landscaping and Lawn Care
Responsible landscaping and lawn care are critical components of stormwater pollution prevention, as common yard maintenance activities can contribute significant pollutant loads to local water bodies. With an estimated 25 to 30 million acres of turf in the United States, lawns represent a land area larger than most agricultural crops. The fertilizers and pesticides applied to these vast areas contain nutrients like nitrogen and phosphorus, as well as other chemicals that can be easily washed off by rain or irrigation. When these pollutants enter the storm drain system, they flow untreated into streams, rivers, and lakes.
The primary water quality impact of nutrient runoff is eutrophication, an over-enrichment of water bodies that leads to excessive algae growth. These algal blooms block sunlight, consume dissolved oxygen as they decompose, and can create “dead zones” where fish and other aquatic life cannot survive. Pesticides and herbicides can be toxic to aquatic organisms and may contaminate drinking water sources. By adopting more sustainable lawn care practices, property owners and municipalities can significantly reduce these harmful impacts and protect the health of local watersheds.
How the pollution pathway works
The pollution pathway for lawn care stormwater begins when fertilizers, pesticides, herbicides, or loose soil are applied to or exposed on a lawn. During a rainstorm or excessive irrigation, water flows over the turf, picking up and dissolving these substances. Research has shown that lawns, particularly when the soil is compacted, can generate more surface runoff than previously assumed. This chemical-laden runoff travels from the yard, often across impervious surfaces like driveways and sidewalks, and directly into a street gutter or storm drain inlet.
Unlike wastewater from homes, which goes to a treatment plant, stormwater entering a storm drain system is typically discharged directly into the nearest stream, river, or lake without any treatment. Like runoff from residential car washing, stormwater from lawns carries its pollutant load directly to receiving waters. An estimated five to seven pounds of pesticides are applied per acre of urban lawn annually, and fertilizer application rates are often comparable to those used for row crops. This direct conveyance means that excess nutrients and chemicals applied in a yard can impact aquatic ecosystems within hours.
Recommended practices
Implementing best practices for landscaping and lawn care can dramatically reduce pollutant runoff. These strategies focus on applying only what is necessary, reducing runoff volume, and using natural alternatives where possible.
Soil Testing and Nutrient Management
The most important step before applying fertilizer is to conduct a soil test. Surveys show that only 10% to 20% of homeowners test their soil to determine actual nutrient needs. A soil test from a local cooperative extension or private lab provides specific recommendations for the amounts of nitrogen, phosphorus, and potassium required for a healthy lawn, preventing over-application.
- Test soil every 3-4 years to understand its composition and pH.
- Select fertilizers based on soil test results. Many established lawns do not need additional phosphorus.
- Use slow-release nitrogen fertilizers, which provide a more controlled supply of nutrients and are less likely to be lost in runoff.
- Avoid fertilizing before a heavy rainstorm is forecast.
- Never apply fertilizer to frozen ground or dormant turf.
- Sweep any fertilizer that lands on driveways, sidewalks, or streets back onto the lawn.
Integrated Pest Management (IPM)
IPM is an ecosystem-based strategy that focuses on long-term prevention of pests through a combination of techniques. It prioritizes non-chemical methods and uses pesticides only as a last resort.
- Regularly monitor the lawn for signs of pest problems. Identify pests correctly before taking action.
- Use pest-resistant turfgrass varieties suited to the local climate.
- Encourage natural predators like birds and beneficial insects.
- Use mechanical controls like hand-pulling weeds or using traps for insects.
- If pesticides are necessary, use the least toxic product available and apply it only to affected areas (“spot treatment”) rather than broadcasting it over the entire lawn.
Water-Wise Landscaping and Mowing
Reducing water use and managing yard trimmings can help minimize runoff and the need for chemical inputs.
- Water lawns deeply but infrequently to encourage deep root growth, which makes grass more drought-tolerant. Early morning is the best time to water to minimize evaporation.
- Practice “grasscycling” by leaving grass clippings on the lawn after mowing. The clippings decompose quickly, returning valuable nutrients (especially nitrogen) to the soil and reducing or eliminating the need for fertilizer.
- Mow at a higher setting (3 to 4 inches). Taller grass shades out weeds, develops a deeper root system, and is more resilient to drought and pests.
- Reduce the total area of turf grass by converting portions of the yard to native plant beds, meadows, or mulched gardens. Native plants are adapted to the local climate and typically require less water, fertilizer, and pest control.
Surveys consistently show a disconnect in public perception. In one Minnesota study, only 21% of homeowners believed their own lawn contributed to water quality problems, while more than double that number felt their neighbor’s lawn was a source of pollution. This highlights the challenge and importance of educational outreach that helps residents see the cumulative impact of individual actions.
Building a municipal program
Municipalities can play a significant role in promoting watershed-friendly lawn care through a combination of outreach, training, and partnerships. Since lawn care is one of the most common activities homeowners engage in, effective programs can achieve widespread residential stewardship.
Public education campaigns are a primary tool. To be effective, these campaigns must clearly connect yard activities to local water quality problems like algal blooms. Rather than using complex or preachy messaging, successful outreach often uses simple, direct, and even humorous messages delivered through a mix of media, including television, radio, and print. Regional campaigns that pool resources from multiple communities can afford higher-quality production and reach a wider audience.
Engaging with lawn care professionals and garden center employees is another crucial strategy. These individuals are a primary source of information for many residents. Municipal or regional programs can offer training and certification for lawn care companies that commit to environmentally friendly practices. The state of Virginia’s Water Quality Improvement program, for example, allows participating companies to use their involvement as a promotional tool. Similarly, programs like Florida Yards and Neighbors have partnered with national hardware chains to train store staff, ensuring customers receive sound advice at the point of sale.
Evaluating program effectiveness through methods like “before and after” market surveys is essential for refining outreach techniques and demonstrating results. An example of a successful local program is the Water-Wise Gardener Program in Prince William County, Virginia. Operating on an annual budget of about $30,000 with 1.5 staff and Master Gardener volunteers, the program achieved an estimated 20-ton reduction in fertilizer application over five years from its 700+ participants.
| Study Location & Year | Respondents | Fertilizing (%) | Soil Testing (%) | Other Notes |
|---|---|---|---|---|
| Chesapeake Bay (Swann, 1999) | 656 | 50% | 16% | Fertilized 1.73 times/year |
| Maryland (Smith, 1994) | 100 | 88% | 15% | 58% grasscycled |
| Maryland (Kroll and Murphy, 1994) | 403 | 87% | – | – |
| Virginia (Aveni, 1998) | 100 | 79% | >20% | – |
| Maryland (HGIC, 1996) | 164 | 73% | – | Fertilized 2.1 times/year |
| Michigan (De Young, 1997) | 432 | 75% | 9% | 69% grasscycled; Fertilized 1.9 times/year |
| Minnesota (Morris and Traxler, 1996) | 981 | 75% | 12% | 40% grasscycled; Fertilized 2.1 times/year |
| Minnesota (Dindorf, 1992) | 136 | 85% | 18% | 78% grasscycled |
| Wisconsin (Kroupa, 1995) | 204 | 54% | – | Fertilized 2.4 times/year |
| Washington (Hardwick, 1997) | 406 | 67% | – | – |
| Florida (Knox et al., 1995) | 659 | 82% | – | 59% grasscycled; Fertilized 3.2 times/year |
Effectiveness
While comprehensive data on the effectiveness of lawn care education programs is still developing, source area monitoring clearly demonstrates the need for such programs. Research in Marquette, Michigan, found that nitrogen and phosphorus concentrations in residential lawn runoff were five to ten times higher than in runoff from any other urban source area. This confirms earlier Wisconsin findings where residential lawns yielded the highest phosphorus concentrations among twelve urban pollutant sources. The high pollutant loads from these areas can be modeled using tools like a Simple Method runoff calculator to estimate their watershed-scale impact.
Evaluations of outreach programs suggest that behavior change is achievable. Both broad media campaigns and intensive training workshops have been shown to produce a 10% to 20% improvement in specific behaviors among their target audiences. Media campaigns are cost-effective for raising general awareness, costing just a few cents per resident reached. Intensive training, while more expensive per person, is more effective at changing complex individual practices. A comprehensive municipal pollution prevention program often requires a combination of both approaches to maximize impact.
Frequently Asked Questions
Why is lawn fertilizer a problem for streams and lakes?
When fertilizer is washed off lawns by rain, its nutrients—primarily nitrogen and phosphorus—enter storm drains and flow directly to local water bodies. These nutrients act like fertilizer for algae, causing excessive growth known as algal blooms. These blooms can make water cloudy, produce toxins, and block sunlight from reaching underwater plants. When the algae die and decompose, the process consumes dissolved oxygen in the water, creating “dead zones” where fish and other aquatic life cannot survive. This overall process is called eutrophication and is a major cause of water quality impairment.
How often should soil be tested for nutrient levels?
For most residential lawns, testing the soil every three to four years is sufficient. A soil test provides a baseline understanding of the soil’s pH and its existing levels of key nutrients like phosphorus, potassium, and organic matter. This information is critical for determining exactly what type and amount of fertilizer, if any, is needed. Applying nutrients without testing is like taking medicine without a diagnosis—it can be wasteful and potentially harmful. Local university cooperative extension offices often provide affordable soil testing services and can help interpret the results.
What is “grasscycling” and does it really work?
Grasscycling is the practice of leaving grass clippings on the lawn after mowing instead of bagging them. The clippings are mostly water and decompose quickly, releasing valuable nutrients back into the soil. A season of grasscycling can provide a significant portion of a lawn’s annual nitrogen requirement, reducing or even eliminating the need for synthetic nitrogen fertilizer. It saves time and effort by eliminating the need to bag and dispose of clippings. For grasscycling to work best, mow when the grass is dry and cut no more than one-third of the grass blade’s height at a time.
Are native plants harder to maintain than a traditional lawn?
While native plants require care during their initial establishment period (typically the first one to two years), they are often much easier to maintain than a traditional turf grass lawn in the long run. Because they are adapted to the local climate, soil, and rainfall patterns, mature native plants typically require less watering, little to no fertilizer, and minimal pest control. They also provide critical habitat and food for local wildlife, including birds and pollinators. Converting a portion of a high-maintenance lawn to a native plant garden can reduce yard work, save money, and decrease stormwater runoff.
What is Integrated Pest Management (IPM)?
Integrated Pest Management (IPM) is a sustainable, science-based approach to managing pests and diseases. Instead of simply reacting with chemical pesticides, IPM focuses on long-term prevention. It involves monitoring for pests, correctly identifying them, and understanding their life cycles. The first line of defense includes cultural practices like choosing pest-resistant plants and improving soil health. If intervention is needed, mechanical (e.g., traps) or biological (e.g., beneficial insects) controls are preferred. Chemical pesticides are used only as a last resort, applied selectively to minimize harm to non-target organisms and the environment.
How much does it cost to run a municipal lawn care outreach program?
Costs vary widely depending on the scale and methods used. Simple materials like brochures can cost as little as $0.10 to $0.50 each to produce. More comprehensive programs require dedicated staff time and a larger budget. For example, the Water-Wise Gardener Program in Prince William County, Virginia, operated on an average annual budget of about $30,000, which supported 1.5 staff members and volunteer coordination. Municipalities can often save money by partnering with neighboring communities on regional media campaigns or by utilizing existing educational materials from university cooperative extension offices.
What are the best alternatives to a large turf grass lawn?
There are many attractive and ecologically beneficial alternatives to a monoculture turf lawn. Converting portions of a yard to native plant beds, wildflower meadows, or shrub borders can reduce maintenance and provide habitat for pollinators. Low-growing native groundcovers can create a lawn-like effect in some areas with less mowing and watering. For high-traffic areas or spaces where plants struggle, permeable hardscapes like patios made from pervious pavers or gravel paths can be a functional and attractive option that still allows rainwater to soak into the ground, reducing runoff.