Fertilizing Facts

Okay, so it's not the most glamorous part of growing a showstopping garden. But a little nudge from fertilizer can make the difference between an average performance and a spectacular one.

Not just any old fertilizer will do, though. It's important to choose the right one for the job. To find out what nutrients your plants need, conduct a soil test. This tells you exactly what to apply, and how much.

Shopping for fertilizer and applying it may seem perplexing at first. But follow these simple suggestions and you'll be fertilizing like a pro in no time—and your garden will get the standing it deserves!

Read the Label

All fertilizers contain the same basic information. Once you know what you're looking for, the task becomes less daunting.

The front of every bag contains three numbers, such as 10-10-10 or 10-15-10 or 6-3-0.

These represent: percentage of nitrogen (first number); phosphorous in the form of phosphate (middle number); potassium in the form of potash (last number).

Plants need all three of these elements. The rest of the material is filler that dilutes the fertilizer so it's easier to apply.

An ordinary balanced fertilizer (formulation 10-10-10 or 12-12-12) can be used for most garden plants in most areas. Because too much of any one nutrient can be harmful, however, it's important to conduct a soil test before choosing a fertilizer.

Many fertilizers also are labeled as fast- or slow-release, indicating how quickly the nutrients are available to the plant.

Fast-release ferilizers dissolve in water and are readily available. They're fast-acting and less expensive, but pose a greater risk of fertilizer burn and groundwater pollution if misapplied.

Slow-release fertilizers release small amounts of nutrients for plants to use over time. They have a lower burn potential and require fewer applications, but usually cost more.

How to Apply

The fertilizer bag usually provides application directions, but there are a few basic tools and techniques you can use to get fertilizers working for you.

Drop and broadcast spreaders can be used to apply granular fertilizer to large areas, such as established lawns, for before planting large lawns, landscape beds and gardens.

In existing gardens, broadcast when the plants are dry. Brush off any granules that land on the leaves. Lightly culitvate, then water so the fertilizer soaks into the soil.

Use hand-held spreaders for applying granular fertilizer to small or medium-sized gardens. With this technique, you can appy fertilizer to only the plants that need it. Sprinkle on the gorund around the base of your plants and lightly scratch into the soil with a trowel or rake. Unless a steady rain is predicted, water right away.

You can make your own spreader by punching holes in the bottom of a coffee can. Make sure an even flow of fertilizer is applied. For small areas, hand applications are fine. Wear gloves to protect your skin.

Hose-end applications mix liquid or water-soluable fertilizer with water, allowing you to fertilize large areas of lawn, shrubs, trees and flowers.

General Guidelines

If you don't get your soil tested, follow these general guidelines on what to apply to various plantings and when.

Annual flowers should be fertilized before planting with a low-nitrogen formula. Use 2 to 3 pounds per 100 square feet per season. You can apply it all with one application of slow-release fertilizer, or make three 1-pound applications spaced throughout the season.

Ground covers should be fertilized with nitrogen in spring. Fertilize yearly or every other year.

Perennials should be fertilized in spring with compost or aged manure. Apply 2 inches every 2 to 3 years, using additional fertilizer as needed.

To keep containers looking good, add a slow-release fertilizer such as Osmocote to your soil mix before planting. Every time you water, a little fertilizer is released. This gives plants a steady flow of nutrients and eliminates the messy job of mixing fertilizer with water.

Trees and shrubs can be fertilized every 3 to 5 years as needed in fall after a hard freeze, or in the spring before growth begins. For new plantings, wait a year before adding fertilizer.