If a flawless lawn is your goal, this fact sheet is not for you. This guide is for those who desire a lawn that's healthy, easy to care for and easy on the environment.  The purpose is to minimize your lawn care chores, while maximizing water quality protection.

THE PROBLEM

While all plants need a certain amount of fertilizer for healthy growth, too much can weaken grass and increase susceptibility to disease. When you apply more fertilizer than plants need or you over water, it not only wastes your time and money, the fertilizer can end up in nearby lakes and streams.  This is a problem, because it stimulates growth of algae and aquatic weeds in our lakes and streams and can lead to fish kills.

LAWN CARE BASICS

Fertilizer:
Fertilize the grass - not walkways, driveways, wetlands or wells. Because rainwater tends to seep into lawn areas, very little of the fertilizer applied to healthy, actively growing turf will leave a lawn as overland runoff. A small amount of soluble nitrogen fertilizer may leach into the deeper groundwater - between three percent (for well-managed lawns) and up to 15 percent (for lawns that are over-fertilized and over-watered). But up to 100 percent of the fertilizer that lands on walkways, driveways, drainage ditches and nearby wetlands can eventually wash into the nearest water body through the storm sewer system or drainageways.

Fertilizers applied in the immediate vicinity of a well have a greater chance of seeping into underground water supplies if they are not taken up by turfgrasses. If you rely on your own well for drinking water, it is a safe practice to maintain a 20 foot protection zone around your well. Keep fertilizers, pesticides, and lawnmower maintenance activities out of this zone.

Sweep all fertilizer, soil, and vegetation off paved surfaces. If you accidentally spread fertilizer on walkways and other impervious surfaces, sweep - do not wash - it back onto the grass. In addition to fertilizer, soil particles, grass clippings and leaves also contain nitrogen and phosphorus which can lower water quality. Therefore, it's important to sweep these off paved surfaces, too. Too many piles of grass clippings and leaves raked into streets and drains can clog stormdrains, causing flooding. As this debris decomposes, it also uses up oxygen in downstream waters, further deteriorating water quality.

Use slow-release fertilizers - Look for 50 percent or greater water-insoluble nitrogen. Slow release fertilizers are those containing more than 50 percent water-insoluble nitrogen (WIN). These release nitrogen slowly over extended periods of time and are therefore less likely to leach nitrate into groundwater. Also, because you apply them less frequently, it saves you time.

It is crucial, however, to apply slow-release fertilizers at the recommended time, since you cannot closely control the release of nitrogen otherwise. Because natural organic fertilizers (like bone meal and manures) release nitrogen as they decompose, release tends to be quicker in warm weather when decomposition speeds up. Cold soils in autumn slow decomposition, so little nitrogen is discharged until the following spring.

Clippings:
Reduce your fertilizer requirement by leaving grass clippings on the lawn. As long as you mow often enough, clippings will disperse well and filter into the soil. Contrary to popular belief, clippings do not cause thatch buildup. As clippings decompose, they provide organic matter to the soil; this improves water retention and returns nitrogen to the lawn. Since 30-40% of the nitrogen used by grass is in the clippings, you can reduce your total lawn fertilizer application rates by 30%, or eliminate one feeding each year by leaving the clippings.

If you decide not to leave clippings on the lawn, compost them and use the finished compost in gardens, around shrubs, or as a lawn top dressing. Be sure to keep clippings, leaves and other yard waste away from drainage ditches, wetlands, and curb inlets.

Watering:
Most lawns in Indiana will survive without irrigation. Grasses will normally go dormant in warm dry weather anytime between June and September if they aren't watered. Healthy, normal lawn grasses will recover and resume growth once moisture becomes plentiful again. Lawns might die from lack of water if they are on extremely sandy soil, not fully established, or over-fertilized.

If you decide to water, do so only during dry periods - and, then, no more than an inch at a time. Established lawns need about one inch of water a week, so if less than an inch of rain has fallen, add  just enough to make an inch. Place a rain gauge or straight-sided can near the sprinkler to track natural rainfall and measure the amount you apply. Water before 9 a.m. to cut down on the amount lost to evaporation.

Mowing:
Adjust mower height. Mowing height is probably the single most important factor in maintaining healthy turf. Grass kept at a height of 2 to 3 inches can withstand heat stress better than close clipped grass. This higher mowing height encourages deeper rooting, makes the need for watering and fertilizing less frequent, and enables the grass to compete better against weeds.

LAWN CARE OPTIONS

What kind of lawn do you want? We recommend three levels of care for minimum maintenance and good water quality protection depending on the amount of effort you are willing to devote to a lawn and how you expect it to look.

• Utility lawn - Mow to a height of 2 to 3 inches and leave clippings to decompose on the lawn. Rely on rainfall and naturally occurring nutrients to maintain established lawns with no fertilizer and no watering. Although the taller mowing height preserves moisture and discourages weeds, you can expect the grass to turn brown during dry spells and for clover, dandelion and other "weeds" to provide a diverse groundcover.

• Easy-care - Maintain 2-3 inch mowing height and return clippings as above. Apply fertilizer once in the early spring OR fall for thicker, greener grass. Application rate should be 0.5 to 1.0 lbs of Nitrogen (more than 50% WIN or organic compost) per 1000 square feet of yard.  The thicker grass helps outcompete weeds. Water no more than 1 inch per week if you want to prevent the grass from becoming dormant and turning brown during drought periods.

• Balanced care - Maintain 2-3 inch mowing height and return clippings as above. Spread fertilizer in the early spring and fall (late spring also if clippings not left on lawn) for steady growth. Application rate should be 0.5 to 1.0 lbs of Nitrogen (more than 50% WIN or organic compost) per 1000 square feet of yard.  Water 1 inch per week to maintain growth during dry spells.

To determine how many pounds of fertilizer you will need to apply 1/2 lb of nitrogen per 1000 square feet of lawn, simply divide 100 by twice the percentage of nitrogen (N) in the fertilizer. For example:

Organic fertilizers - Organic forms of lawn fertilizers are generally high in water insoluble nitrogen and tend to release nitrogen slowly. Examples include cottonseed, bone or blood meals; fish emulsion; compost; and manures. Organic fertilizers may contain relatively low concentrations of actual nutrients, but they perform other important functions - such as increasing soil organic content and providing micronutrients that synthetic formulations do not. More organic forms of lawn fertilizers are now reaching the market, giving consumers a wider variety of slow release fertilizers to choose from.

Fertilizer-pesticide combinations - Some fertilizers are pre-mixed with herbicides to eliminate weeds. Others are combined with insecticides and marketed as "complete" treatments to kill grubs and other pests. Often, these "weed `n feed" combinations are marketed as multi-step programs that provide the sure path to a perfect lawn. But, unless you are certain your lawn needs these materials, they increase the cost of fertilizing and can even harm beneficial lawn insects.

Before reaching for a pesticide or herbicide, first identify the specific problem. This will ensure effective treatment. Consider non-toxic options, such as biological pest controls. When a pesticide is necessary, use the least toxic alternative that will control the problem. Follow all label precautions. Visit the Household Hazardous Waste Factsheet  for less toxic alternatives.  Contact the Purdue Extension office to correctly identify lawn problems and for information on choosing control options.

MORE LANDSCAPE CARE TIPS

If you wish to give your landscape a little extra care beyond the basics we've suggested, here are a few more suggestions:

Test the soil. Different types of soil require different fertilizer treatments. If your soil pH is low, simply adding lime can noticeably improve your lawn by making nutrients more readily available to turfgrass. Your Purdue Extension Office  can help you with what your soil needs, how much lime to apply, and what fertilizer is best for your lawn or garden.

Choose improved varieties. If you're establishing a new lawn or renovating a poor one, look for improved varieties and those particularly suited to your sunny or shady site. Bear in mind that grass seed mixtures are better for your lawn than single-species.