Function

• Lawns and flowers alike need the same nutrients to thrive.lawn and border bed image by TMLP from Fotolia.com
  
  Plants need three key nutrients to thrive: nitrogen, phosphorus and potassium. When there is a soil deficiency, and one or all of these nutrients are missing or deficient, the soil suffers. Properly applying fertilizer brings the numbers back to needed levels.
  
  

Identification

• Properly balanced soil is a necessity.growing araucaria in soil image by joanna wnuk from Fotolia.com
  
  To find out what the nutrient levels of the soil are---and thereby find out what type of fertilizer will be most effective---run a test on a soil sample. There are a number of places that can run such a test, including the cooperative extension of a local college or most agricultural businesses.
  
  

Types

• Make sure household pets are safe from fertilizers.dog image by Renata Osinska from Fotolia.com
  
  Fertilizers come in organic and non-organic varieties. There are advantages and disadvantages to both. For example, organic fertilizers have a steadier release rate and last longer, but they usually are more expensive and can encourage household pets to dig in the lawn. Chemical fertilizers are inexpensive and created with an exact formula. They can add to environmental problems and may decrease the soil's fertility over time.
  
  

Misconceptions

• Over-fertilizing can be too much of a good thing.Grass image by David Prantl from Fotolia.com
  
  More is not necessarily better. Too much fertilizer can burn the lawn and can kill the grass. Burn it badly enough, and it will have to be re-seeded.
  
  

Considerations

• Lawns change over time, and fertilizer may need to change, too.hose on lawn image by Coralie Palmeri from Fotolia.com
  
  Just as environmental conditions change, so do the needs of the lawn. Take regular soil samples---at least one every two years---to make sure the fertilizer that's being applied is still the correct one.