Pests in Gardens and Landscapes: Quick Tips

Lawn Fertilizing

Published   5/20

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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.

Prepare to fertilize your lawn.

  • Identify the type of grass you have to select the proper fertilizer rate and application timing.
  • Apply fertilizers only when grass is actively growing.
  • Avoid using fertilizer/pesticide combinations unless the presence of the pest coincides with a scheduled fertilizer application.
  • Water lawns deeply the day before you fertilize.
  • Use appropriate application equipment.

How much fertilizer should you use?

  • Fertilizer amount 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.

  • Use slow-release fertilizers to minimize leaching.
  • Use drop spreaders rather than rotary spreaders to avoid off-target fertilizer application.
  • Apply fertilizer only to planted areas where plant roots can take it up. Keep fertilizer off walkways and bare areas.
  • After fertilizing, water just enough to wash fertilizer off the grass blades and into the soil after applying. 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.

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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Agriculture and Natural Resources, University of California

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