Going by the Numbers

The numbers on this bag of fertilizer are clear and easy to read, but what do they really mean?

The numbers on the fertilizer packages refer to the percentage of nitrogen, phosphorous and potassium by weight. For synthetic fertilizers, the higher number does not necessarily mean the "better" product, but it does mean that the fertilizer will dissolve more quickly in water than one with a lower percentage indicator. The quick solubility means that a good amount of fertilizer that's been applied is wasted because it either leaches into the subsoil or runs off into storm drains. To find out what is synthetic and what is natural, read the ingredients and check the percentages. If the numbers on the package equal 20 or more, there is a good chance it is synthetic. If the numbers are less than or equal to 20, the product is usually natural.

Also in this Episode

Gardening by the Yard : Episode GBY-106
•	Fertilizer Overview
•	Going by the Numbers
•	Foliar Feeding
•	How and When to Fertilize
•	Compost and Manure