Northwest Florida's weather patterns can present challenges to maintaining a healthy lawn. Heavy rains promote fast growth and relentless sunshine causes lawns to fade.

In the last 200 days, we have received at least 68 days of rain. While the rest of Florida was experiencing record drought earlier this year, the Panhandle was experiencing torrential downpours.

With every drop of rain, your spring fertilizer is being metabolized by the lawn, reducing how many nutrients remain in the soil. Even the best slow-release fertilizer will only last 3-4 months. The message is: "It's time for more fertilizer."

A healthy lawn is an important component of the urban landscape. Not only do lawns increase the value of a property, they also reduce soil erosion, filter stormwater runoff, cool the air, and reduce glare and noise. A healthy lawn effectively filters and traps sediment and pollutants that could otherwise contaminate surface waters and groundwater. Lawns require nutrients throughout the growing season to stay healthy. In Northwest Florida, the growing season is typically April to October.

Proper fertilization consists of selecting the right type of fertilizer and applying it at the right time and in the right amount for maximum plant uptake. The type of fertilizer should be based on a soil test, available through the University of Florida-Institute of Food and Agricultural Sciences Extension. The timing of application and amount of fertilizer is dependent on the research-based recommendations for the grass species and the fertilizer analysis of the product being used.

(See the chart for application rates.)

Select only a fertilizer that states that the product is for use on residential turf. Do not use a fertilizer meant for flower or vegetable gardens on lawns. By Florida Administrative Code, Rule 5E-1.003, the Urban Turf Rule requires that the fertilizers being applied to residential lawns are labeled for the site and the application rates are followed. Typically, these products will contain both slow-release nitrogen and low or no phosphorus. Slow-release nitrogen will provide a longer-lasting response from the grass and reduces the potential for burning. Go to http://www.edis.ifas.ufl.edu/pdffiles/EP/EP35300.pdf for more information on the Urban Turf Rule.

With frequent rain, the soil is also losing iron. Keep in mind that the green fading to yellow appearance in your lawn may be an iron deficiency. Before applying your summer fertilizer, put out a liquid chelated iron. It will improve the health of the lawn while you are trying to find a dry day to fertilize.

While it is necessary to water in fertilizer with one-fourth inch of water to reduce burn potential and volatilization, never apply fertilizer when heavy rain is expected. The rainfall over one-fourth inch can encourage runoff or leaching of that fertilizer, which can be costly and environmentally harmful.

Sheila Dunning is an agent at the University of Florida's Institute of Food and Agricultural Sciences Extension office in Crestview.