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Water Quality Program - College of the Environment and Life Sciences

Healthy Lawn Care

A healthy, well-established lawn can out-compete most weeds and withstand a certain amount of stress from drought, insects, and disease.

Lawns can often be renovated with proper fertilizing, mowing, watering, and addressing problems with thatch and soil compaction.

Here are some healthy lawn care tips:

Fertilizing Guidelines 

If you don’t fertilize your lawn and you like the way it looks, then do not fertilize.  If you do fertilize, follow the recommendations below:

Recommendations for Managing Nitrogen ( N ) on Lawns

Do not apply before spring green-up and apply no later than October 15th. Avoid mid-summer fertilizing.

Apply one-half to one-third (or less) of that recommended on the fertilizer bag label and then monitor lawn response. Re-apply at the reduced rate only when lawn response starts to fall below acceptability.

Slow-release fertilizers are preferable to soluble, fast- release ones.

Apply a maximum of 2 pounds of nitrogen per 1000 square feet per year on an established lawn 10 years old or older. Newly seeded turf, especially on new home sites where the topsoil has been removed, may require more.

If a soil test indicates phosphorus  and/or potassium are adequate, then fertilize with only nitrogen. If only blended fertilizers are available, choose the one with the lowest P content.

Recommendations for Managing Phosphorus ( P ) on Lawns

Always test the soil to determine phosphorus  levels before applying. Soil test annually for phosphorus when applying organic fertilizers derived from composts to ensure that levels do not become too high.

If phosphorus fertilizer is required:

Avoid using phosphorus fertilizers on bare ground, unless it is a new seeding.

Use phosphus-free fertilizer on established lawns, unless soil tests indicate that phosphorus is too low.

Avoid applying phosphorus fertilizers when moderate to heavy rain is in the forecast.

Never apply phosphorus fertilizers to saturated or frozen ground.

Other Nitrogen and Phosphorus Management Tips:

Return clippings and mow as high as possible (leave at least 3 inches). Clippings can supply slow-release nitrogen to the lawn and allow for reduced fertilizer applications. On a well-established lawn, this can often supply adequate P and K for the lawn.

Choose grasses, such as fescues, that require less water and nutrient inputs.

Maintain a soil pH of 6.0 to 7.0. This will ensure that most of the nutrients necessary for good turfgrass growth will be available to the grass plants. Monitor pH levels to determine if liming is necessary or not.

Consider seeding white clover or other legumes into the lawn to naturally provide nitrogen.

If supplemental watering is applied, avoid overwatering. Do not exceed a total of 1 inch of water per week, including rainfall amounts. Water wisely.

Leave a buffer strip of at least 25 feet of unfertilized grasses or other vegetation around water bodies (streams, rivers, lakes, estuaries, bays, coastal areas, vernal pools, wetlands, or drainage areas).

Avoid using combination products that include both fertilizer and weed killers as the application rates of such products are based on the weed killer rather than the fertilizer. Pesticides should not be applied within 25 feet of surface water.

When establishing a new lawn, organic matter content should range from 3% to preferably 5%. Incorporate compost or another organic material into the soil to raise the organic matter content as needed.

Proper Application Methods

It is very important to measure the actual area to be treated with fertilizers and/or pesticides and to calibrate your spreader. This ensures that you are applying the amount of product that you intend.

Avoid spreading fertilizer on paved areas or near storm drains or drinking water wells. Sweep up these areas with a broom, do not wash with a hose.

A drop spreader allows for more accurate application of fertilizers and pesticides.

Compost and other organic fertilizers are still sources of nutrients, so they must be applied at the proper rate and time using proper application methods.

Use the following practices when controlling pests:

  • Properly identify the pest problem.
  • Is the problem bad enough to warrant chemical treatment?
  • Learn about the pest — identify cultural, mechanical, biological options for controlling the problem rather than using pesticides.  Find out if the pest problem is due to improper fertilization, watering or mowing practices as these can cause shallow roots, disease and other lawn health problems.
  • If chemical control is necessary, spot treatment may be the best option.
  • Choose the least toxic pest control method.

URI Plant Protection Clinic: (401) 874-2900
Assistance with identification of plant insects and disease

Soil Compaction, Thatch and Mowing

Soil compaction and thatch build-up result in shallow roots and reduces water and air flow flow into the soil. Mechanical soil aeration, vertical mowing (thatch removal) and coring can help loosen compacted soil. Soil compaction in your yard can result from frequent vehicle access and foot and animal traffic.

Thatch is a dense layer of dead grass, stems and roots that develops between the soil surface and the growing grass. While some thatch is normal and desired, excessive thatch problems are often a sign of over-watering and improper mowing. Mechanical de-thatching in the early fall is recommended for lawns with more than one inch of thatch build-up.

Proper mowing at the correct heights and frequencies with a sharp blade is very important for lawn health. Mowing at heights between 2 and 3 inches is best to encourage deeper roots, discourage weeds and reduce evaporation.

Download a Printable Factsheet:

Healthy Lawn Care and Renovation

Additional Resources

These lawn fertilization guidelines are adapted from: Guillard, K. 2008. New England Regional Nitrogen and Phosphorus Fertilizer and Associated Management Practice Recommendations for Lawns Based on Water Quality Considerations. University of Connecticut.This material is based in part upon work supported by the Cooperative State Research, Education, and Extension Service, U.S. Department of Agriculture, under agreement number 2006-51130-03956.

 

University of Connecticut Cooperative Extension Water Quality and the Home Landscape
Sustainable Landscaping: Turf Management Page

URI Master Gardener Hotline at 1-800-448-1011

URI Plant Protection Clinic: (401) 874-2900
Assistance with identification of plant insects and disease

Soil Testing Labs
University of Connecticut soil testing lab 
University of Massachusetts soil testing lab

 

 

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