2007 Year in Review

Avoid Early Spring Fertilizing

Fertilizing lawns may not be the best on the grass in the long run, according to David Robson, University of Illinois Extension Horticulture Educator. Unfortunately, advertising and chemical combinations in the spring makes it next to impossible not to apply some form of plant food.

Most Illinois lawns are composed of cool season grasses such as Kentucky bluegrass, turf-type tall fescue and perennial ryegrass. Shady areas may contain additionally creeping, red or chewings fescue. These grasses remain actively growing as long as temperatures are lower than 85 degrees Fahrenheit.

The primary purpose of spring lawn care is to produce a lawn tough enough to survive the summer. The ideal lawn care period starts September 1 when temperatures are on the slow decline.

Studies at the University of Illinois indicate grass roots are actively growing when temperatures are between 55 and 65 degrees Fahrenheit. Grass shoots start developing when temperatures range between 60 and 75 degrees.

Grass roots are the first to start thriving when spring temperatures warm. New and deeper roots are formed, creating a network of interlocking roots. The deeper the roots, the more likely the grass plant will be able to survive hot, dry summer conditions. In fact, spring lawn care should be aimed at developing a deeper and more extensive root system than shoot growth. Unfortunately, nitrogen fertilizer promotes shoot growth at the expense of the root system. Even with cool soil temperatures, the grass plant shifts growth to shoots to use the nitrogen applied. The root system stays undeveloped.

Homeowners have been conditioned to expect a thick, green lush lawn in the spring as soon as temperatures warm. Part of the problem can be traced back to crabgrass killer combination, states Robson. Most crabgrass pre-emergence weed killers contain fertilizer to aid in the greening of the lawn. Pre-emergence weed killers must be applied before the weed emerges; since crabgrass germinates by mid-April, most chemical applications are applied by the first of April.

The turf industry tends to promote the need for greening in early spring with weed control. Ultimately, it’s the homeowner who demands the green color in early spring, as leaves are budding and tulips blooming.

The best bet is to search for a crabgrass or pre-emergence weed killer that doesn’t contain fertilizer. They may be more difficult to find, but are available. Check with local garden centers, greenhouses or nurseries. Lawn care services should be contacted to limit early spring nitrogen applications.

Lawns can be fertilized in the spring. However, wait until the roots have stopped growing.

Fertilize with a pound of actual nitrogen fertilizer around the middle of May. Check the fertilizer package for proper application information.

Late fall fertilizer applications should provide sufficiently enough fertilizer to stimulate the grass in spring. Homeowners are encouraged to remember to apply plant food in November of this year.

For more information on lawn fertilizer, contact your local extension office.

by  Editor, theCity1.com
March 20, 2007