Simply put, a fertilizer has nutrients to help plants grow. Many years ago, farmers found that composted manure from their farm animals were beneficial for healthy plant growth. Today, most of us buy fertilizer in bags and bottles at our favorite garden center.

A trip to the store, however, can be a little confusing.  What do those three numbers displayed on the packaging mean?

Without getting too technical, the three numbers show the percentage of available nitrogen (N), phosphate (P) and potassium (K). By law, it always goes in that order. If you see a fertilizer with 20-5-10, it means the fertilizer contains 20% available nitrogen, 5% phosphate and 10% potassium. (Other nutrients and filler make up the difference.)

What does that mean to your plants?

  • Nitrogen promotes chlorophyll, producing greener and more rapidly growing plants. If your plants aren’t as green as they should be, use a fertilizer with nitrogen. Most lawn fertilizers have relatively high nitrogen content and can increase the need to mow your lawn more frequently.
  • Phosphate improves root growth, flowering ability and bloom size. Use a fertilizer with a larger “middle number” to encourage root growth during transplanting or to encourage blooms.
  • Potassium enables the photosynthesis process and improves plant resistance to cold spells, drought, and insect attacks. Many people use a potassium fertilizer when the seasons change.

Read the label for specific instructions and uses. It may seem boring, but reading that label will prevent bad results. Overuse or misuse of fertilizer can kill your plants and that’s certainly not your intention. Read the label, follow the instructions and enjoy the results!