Fertilizing is an important part of gardening because given at the right time, fertilizers can really give your plants a boost. When you're trying to decide on which fertilizer to use, keep this list handy to make sense of fertilizer terminology:

  • Complete fertilizers: These fertilizers contain all three macronutrients: nitrogen (N), phosphorus (P), and potassium (K).

  • Incomplete fertilizers: Incomplete fertilizers are missing one or more of the macronutrients, usually the P or the K.

  • Chelated micronutrients: If your plants don't get nicely green (they remain mottled yellow and green, or just yellow), no matter now much nitrogen you apply, you probably have a deficiency of micronutrients — iron, manganese, or zinc. These fertilizers are in a form that allows a plant to absorb them more quickly than the more commonly available sulfated forms.

  • Organic fertilizers: Organic means that these fertilizers derive their nutrients from something that was once alive. Examples include blood meal, fish emulsion, and manure.

  • Slow-release fertilizers: These fertilizers provide nutrients to plants at specific rates under particular conditions. Some slow-release fertilizers can deliver the benefits of their nutrients for as long as eight months.

  • Foliar fertilizers: Apply this plant food to leaves rather than to the roots (ground). You can use most liquid fertilizers as foliar fertilizers, but make sure the label says you can.