Fall Fertilizing

Fertilizing is an important aspect in keeping a healthy lawn.  The three main nutrients for turfgrass are nitrogen, phosphorous and potassium.  Nitrogen enables turfgrass to make chlorophyll which is used to perform photosynthesis.  Phosphorous is important for growth and potassium helps turfgrass become hardy against certain stresses such as drought and traffic stress.   Most of Florida’s soil has enough phosphorous to supply the nutritional needs of a lawn, but nitrogen and potassium need to be supplemented in the form of fertilizer. 

The amount and frequency of fertilizer applications vary with each species of grass.  Below is a chart showing the proper amount and frequency of fertilization for each species in a growing season. 

Nitrogen fertilizer recommendations for Florida turfgrass species

Species/location in Florida	Interim N recommendations (lbs 1000 ft-2 yr-1)*, **
Bahiagrass – North	2–3
Bahiagrass – Central	2–4
Bahiagrass – South	2–4
Bermudagrass – North	3–5
Bermudagrass – Central	4–6
Bermudagrass – South	5–7
Centipedegrass – North	1–2
Centipedegrass – Central	2–3
Centipedegrass – South	2–3
St. Augustinegrass – North	2–4
St. Augustinegrass – Central	2–5
St. Augustinegrass – South	4–6
Zoysiagrass – North	3–5
Zoysiagrass – Central	3–6
Zoysiagrass – South	4–6
*Homeowner preferences for lawn quality and maintenance level will vary; therefore, a range of fertility rates is recommended for each grass and location. Additionally, effects within a localized region (i.e., microenvironmental influences such as shade, drought, soil conditions, and irrigation) will necessitate that a range of fertility rates be used. **These recommendations assume that grass clippings are recycled.

Image retrieved from: http://edis.ifas.ufl.edu/ep435

Although fertilizer frequency differs with each species, the growing period is the same for all species growing in the same climate.  An actively growing lawn needs nutrients.  Your lawn should be fertilized as soon as spring green up occurs with subsequent applications throughout the growing season. 

For all of us living in Florida, the last fertilizing period is here.  We should give our grass one last application.  So dust off the spreader and pull out the fertilizer bag this weekend or next.  When you are done, pack it up for the winter and know your fertilizing job is done for the year.   

References:

Trenholm, L. E., Kruse, J. K., & Unruh, J. B. (2010). The Lawn Fertilizer Toolbox. Retrieved form University of Florida, Gainesville, IFAS Extension website: http://edis.ifas.ufl.edu/ep435

Unruh, J. B., Trenholm, L. E., & Cisar, J. L. (2011). Centipedegrass for Florida Lawns. Retrieved form University of Florida, Gainesville, IFAS Extension website: http://edis.ifas.ufl.edu/lh009

 

The Proper Amount of Water

The excessive amount of rain in Gainesville these past months has caused grief and heartache for three homeowners in my neighborhood.  The reservoir area behind their home is flooded and running into their yards leaving their soil constantly saturated.  The lawn of one homeowner, sadly, is dying.  I am not sure if the grass is dying from a fungus or from the roots not getting enough oxygen.  Watching these lawns struggle I ask the question, "what happens when a lawn gets too much water and how much water does it need?"  According to Trenholm, Unruh, and Cisar (2006), too much water can cause a poor root structure, a build up of thatch, and can cause the turf to become susceptible to fungus and insect infestation.  I am sure that I am among many friends when I say that I have had problems with bugs and fungus in my yard this season.  Although the excess water has been due to rain this season, during dry weeks when homeowners over irrigate their lawn are actually inviting fungus and insects to live in their lawn.  This brings me to the second half of my question, how much water does a lawn need?  The short answer is it depends.  It depends on the type of grass you have and how hot it is.  Some of the signs you can look for in your lawn to know when it needs water are when the leaf blade will fold in half, the grass will turn a green gray color, and the grass will not pop back up immediately after walking on it.  During our next dry spell instead of turning your sprinkler system back on to automatic timer, try watching your lawn to give you the signs that it needs water.  Give it a good soak only when your grass is ready for a drink and know that you are helping it resist those pesky insects and fungus. 

           
Watering Your Florida Lawn
 

The tire tracks from the lawnmower show how saturated this ground is.

This homeowner mowed his lawn over a week ago.  There has not been any new growth and many of the blades have turned brown. 

 

Reference:

Trenholm, L.,Unruh, J., & Cisar J. (2006). Watering Your Florida Lawn. Retrieved form University of Florida, Gainesville, IFAS Extension website: http://edis.ifas.ufl.edu/lh025