How to Fertilize Your Lawn

The first step in any lawn-feeding program is to test the soil and find out what type and amount of fertilizer it needs.

How to Understand Fertilizer Types

Fertilizer comes in bags with the contents labeled clearly for easy identification. Three large numbers on the bag—representing nitrogen, phosphorous, and potassium content, respectively—are the main indicators. If a product is labeled 20-10-10, for instance, it means that the bag contains 20 parts of nitrogen for every 10 parts of phosphorous and potassium.

  • Nitrogen: Makes the grass grow greener and faster
  • Phosphorous: Improves root development
  • Potassium: Helps ward off disease

The front label (left) of a fertilizer bag shows the general composition of the product. A more detailed breakdown of the included chemicals appears on the back label (right).

When to Fertilize Your Lawn

Most manufacturers recommend feeding your lawn four times a year: spring, early summer, late summer, and fall. Water-soluble fertilizers are absorbed faster but don’t promote healthy plants as much as water-insoluble fertilizers, which are released more slowly.

The best time of day to apply fertilizer is the early morning, when dew is still on the grass. Dew keeps the fertilizer from blowing away and makes it easier to see which areas you’ve covered, as the spreader’s tracks are visible. To apply fertilizer, use either a broadcast spreader or a drop spreader.

  • Broadcast spreader: Applies fertilizer (and other dry materials) by throwing it off a disk that spins just below the hopper
  • Drop spreader: Releases the fertilizer directly below the hopper; is easier to control but covers just a small area in each pass
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