N-P-K: WHAT DOES IT MEAN FOR YOUR GARDEN?

Understanding, then utilizing a FERTILIZER to use in your flower beds can mean the difference of happy, healthy blooms, or  sad, puny ones.  But, trying to determine which fertilizer to use can seem difficult.  If you know your plants, however, you can easily make the right choice in helping to make your beds be a great success.  The three numbers on every bag of fertilizer tell us what percentage of the three nutrients are in the fertilizer, and they're always in the same order. Annuals, vegetables, trees and shrubs, perennials and lawns each have their own needs.  In this post I will focus on perennials.  N - P - K:  These are the three major nutrients in fertilizers.  "N" is the percentage of Nitrogen in the fertilizer, "P," the amount of Phosphorous,and "K" is the Potassium, or Potash as it is called.  Each of these nutrients affects plants differently, and depending on what your plant needs, you can choose your fertilizer accordingly.  Most plants, like roses, to look their best, require a balanced fertilizer for foliage, blooms, good root development, and proper growth.  Here is a short summary of what each does for your perennial plants:

1. NITROGEN - Plays a huge role in plant health.  It provides plants with the ability to produce more chlorophyll, which allows the plant to grow quickly. They will be taller, greener, and bigger with nitrogen.
2. PHOSPHOROUS - Aids root development, and increases flowering ability and bloom size; it  keeps the plant healthy.  High phosphate fertilizers should be used when you're planting and establishing new plants.  I use triple super phosphate (0-45-0, considered an incomplete fertilizer because it contains only one of the 3 nutrients) when planting my iris, and I always sprinkle it over all the beds in early spring. 
3. POTASSIUM (POTASH) - This helps plants absorb and use water efficiently.  It is easily absorbed into the plant. It guards the plant against diseases and helps plants survive drought conditions and also cold tolerance.  It is best used at the start of winter and summer to protect plants from temperature extremes or when insects or disease has damaged your plants.

Remember that too much of a good thing isn't good when using fertilizers; damage, even death to the plant can occur if too much fertilizer is used.  The fertilizers for vegetable gardens and lawns are different than those used for your flower beds; read the labels and follow directions carefully. Some fertilizers release quickly, others are slow releasers.  I use a quick release for my bulbs rights after they have bloomed, to feed the bulbs for the following year.  I use a slow release, however, for maximum coverage on perennial plants. The release can be over a time period of 3 to even 9 months. Always apply fertilizers on a cool day, before a rain, or water in, so no burn or denitrification (the release of gases into the atmosphere before the plant has time to absorb it) can take place.  So, when choosing fertilizers, relax and just consider what your plants need and you can't go wrong!