Pros and cons of weed & feed fertilizers 02-19-07

Pros and cons of weed & feed fertilizers

Fertilizer granules provide a simple and easy carrier to distribute pre-emerge herbicides that must be applied to our lawns prior to weed seed germination if the herbicide is to be effective. However, there is a downside to using many of these weed and feed fertilizers in the spring for our Southern lawns. Many of these fertilizers are formulated with high nitrogen contents for cool season turf species that can utilize the nitrogen at this time of the year. These fertilizes put on our dormant warm season turf species now will more than likely only feed winter weeds that will compete for space as our lawns begin their flush of spring growth. With too early nitrogen fertilization you may also be setting your lawn up for cold injury from a late season freeze. Therefore, my suggestion is if you use a weed and feed fertilizer as a carrier for your pre-emerge herbicide try to find a fertilizer formulation that is low in nitrogen, or at least one that the nitrogen source is in a slow release form. Wait until you have mowed the lawn at least twice before applying your spring nitrogen fertilization.

Published February 19, 2007

Dr. Wayne Wells is an Extension Professor and Turfgrass Specialist. His mailing address is Department of Plant and Soil Sciences, Mail Stop 9555, Mississippi State, MS 39762. wwells@ext.msstate.edu