Pests in Gardens and Landscapes: Quick Tips

Lawn Fertilizing

Published   3/14

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How to read a fertilizer label

How to read a fertilizer label.

A drop spreader for applying fertilizer.

A drop spreader for applying fertilizer.

An electric mulching mower.

An electric mulching mower.

A good nutrient supply is important for a healthy, vigorously growing lawn. Lawns that are discolored, slow growing, or have weeds or other pest problems might not be properly fertilized. Lawn fertilizers usually supply three main nutrients: nitrogen, phosphorus, and potassium. However, nitrogen is the only nutrient that turfgrass needs on a regular basis. Too much or improperly applied fertilizer can injure lawns and can contribute to water pollution through runoff.

When fertilizing your lawn:

  • Identify the type of grass you have and select the proper fertilizer rate and application timing.
  • Use appropriate application equipment.
  • Deeply water the day before you apply fertilizer.
  • After fertilizing, irrigate just enough to wash the fertilizer off the leaves and into the soil.
  • Keep fertilizer off walkways and bare areas. Apply fertilizer only to planted areas where plant roots can take it up.
  • Apply fertilizers only when grass is actively growing and no more than the recommended rates.
  • Use slow-release fertilizers to minimize leaching.
  • Avoid using fertilizer/pesticide combinations unless the presence of the pest coincides with a scheduled fertilization.

How much fertilizer should you use?

  • Fertilizer application depends on turf species, varying from 2 to 4 pounds of actual nitrogen/ year per 1,000 square feet and usually divided into 3 to 4 applications per year.
  • Generally no more than 1 pound of actual nitrogen per 1,000 square feet should be applied at one time.
  • To calculate the proper rate for your situation, use the fertilizer calculator in the UC Guide to Healthy Lawns.
  • Adjust your spreader according to manufacturer instructions.
  • Use a mulching mower. Grass clippings left on the lawn after mowing will release valuable nutrients back to the soil so you can use less fertilizer.

Prevent fertilizer from polluting waterways.

  • Before watering, sweep any fertilizer on sidewalks, walkways, or driveways back onto lawns—not into street gutters and storm drains.
  • Avoid overwatering to prevent fertilizer and water from running into gutters.
  • Use drop spreaders rather than rotary spreaders to avoid off-target fertilizer application.

Minimize the use of pesticides that pollute our waterways. Use nonchemical alternatives or less toxic pesticide products whenever possible. Read product labels carefully and follow instructions on proper use, storage, and disposal.

Statewide IPM Program, Agriculture and Natural Resources, University of California
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