About Fertilizers

An old gardener’s adage is to “feed the soil, not the plants.” This makes sense because it’s the soil that feeds the plants in most cases. Plants get most of their nutrients from the soil (they get carbon and oxygen from the air) and, in many cases, grow just fine without added fertilizer.

In general, the more extensive a plant’s root system is, the less added fertilizer it needs. Adding fertilizer is most important with young and newly-established plants that haven’t had time to grow an extensive root system yet, with plants in containers that don’t have room to grow an extensive root system, and with rapidly-growing plants whose tops grow faster than their root systems can keep up with.

Gardeners have several decisions to make about fertilizing plants:

  • Which nutrients to add
  • What form of fertilizer to use
  • When to feed
  • How much to feed