Be Wise When You Fertilize

Many trees and landscape plants require little or no fertilizer once they are established and mature. In fact, fertilizers can be hazardous to the health of your yard and the environment when they are misused.

When over-applied, fertilizers may aggravate insect and disease problems and force excessive growth which must be mowed or pruned. Excess fertilizers can run off yards into waterways or seep into aquifers, polluting drinking water.

The decision to fertilize should be based upon the health of the plant, the desired rate of growth, and a soil analysis. A soil analysis will tell you the soil pH and the amounts of nutrients in the soil that are available for plant growth. Soil pH affects the availability of nutrients in the soil. When you choose the fertilizer to use, it should have an analysis, which provides the nutrients that are lacking in the soil.

Landscape Plants

How do I know if it’s time to apply fertilizer?

Look for vegetation showing signs of poor growth, poorly colored leaves (pale green to yellow), leaf size smaller than normal, earlier than normal fall coloring and leaf drop, twig or branch dieback, or little annual twig growth. The method to use when applying fertilizer depends on the type of fertilizer and the plant’s needs. Your soil type will determine how often you should apply fertilizer. Consult your soil test report.


Fertilization of lawns is essential to produce quality turf in Virginia. However, exceeding recommended fertilizer application rates or improper application timing can negatively impact surface water and groundwater quality. A well-planned and environmentally sound turfgrass fertilization program will take the following factors into account

  • Soil type
  • Inherent soil fertility
  • Nutrient source characteristics
  • Desired turfgrass quality or performance
  • Nutrient application rate
  • Application frequency
  • Season of application
  • Application method

Spotlight: Virginia Tech: Fall Lawn Fertilization:


Healthy Virginia Lawn Program

Have the Virginia Cooperative Extension Loudoun County Master Gardeners take a soil sample of your lawn and determine just how much fertilizer and lime you need. Applying too much can deposit excess nitrogen or phosphorus in our local streams.

Two Cooperative Extension Master Gardeners can come to your yard, take a soil sample, and measure the size of your lawn.  (If you have other yard problems they will try to help you there also.)  We send the soil sample to a lab at Virginia Tech, which assays it and replies how much fertilizer and lime should be used to promote a healthy lawn without contributing to nitrogen pollution.  The Extension Master Gardeners then send that information back to you with advice on how to apply the fertilizer and lime.  This guarantees that your lawn will not be the source of additional pollution to our local watershed.  You can feel like a good citizen!  There is a minimal charge of $30 for this service. 

Please see our website for more information: (April through October):
Healthy Virginia Lawn Program

My Backyard measures for scorecard:

  • Walk around your yard at least weekly and observe your plants and lawn for early signs of problems. Credit = 2 inches
  • Fertilize only as needed to maintain the health of lawns and landscape plants. If plants show signs of stress, such as yellow leaves or stunted growth, identify the problem before applying fertilizer. Do not exceed the rate of 1 pound of nitrogen per 1,000 square feet per application.                Credit = 4 inches
  • Most landscape plants benefit from slow-release fertilizers. Buy fertilizers that contain 50% or more of the nitrogen in slow-release forms. Read the label carefully upon application.  Credit = 2 inches
  • Fertilize lawn in the fall – knowing your acreage and reading the label thoroughly.  Do not allow fertilizer to fall on hard surfaces like sidewalks, driveways or the street.  Credit = 3 inches
  • Use Healthy Virginia Lawns program and follow the Nutrient Management Plan report.            Credit = 4 inches


VCE Publication 430-018: Fertilizing Landscape Shrubs and Trees

VCE Lawn Care Publications – Extensive Library