Hunt County Master Gardeners

Seven years ago, I moved to Hunt County.  My neighbors told me the soil in our neighborhood would not grow anything.  I had many oak trees, sand, weeds and a miniscule amount of Bermuda grass.  In my ignorance of what was best for my site, I chose St. Augustine grass.

It would take a book to explain all the problems I have encountered with my St. Augustine turf in the last six years.  Due to diseases and not understanding how important soil samples are, I have replaced my lawn two times.  Ignorance again.

I was introduced to the Master Gardener program my fourth year in this county and my life changed.  Through this program, I learned where I could access a wealth of information on anything Horticulture in nature.

My research for Turf grass recommendations for North East Texas with an emphasis on Hunt County led me to http://aggieturf.tamu.edu.  This site will give you much more information than space for this article can possibly cover.

When deciding what turf is best for your location, it is important to select a species adapted to your specific location. Site considerations include:  shade or sun, soil depth and quality, intended use (lawn, golf course, or athletic field), amount of traffic, amount of rainfall or irrigation, and level of maintenance.

There are five species of turf that are well adapted for Northeast Texas.  Warm season grasses are Bermuda, Centipede, and Zoysia grasses.  Cool season grasses are Ryegrass and Tall Fescue.

Bermuda grass has a very low tolerance for shade.  Water requirements are moderate to low.  Drought tolerance is very good to excellent.  Traffic tolerance is high.  Cold tolerance is moderate.  Salinity tolerance is moderate to high.  Disease potential is low to moderate.  Mow every 3 to 7 days to maintain a height of 1 to 2 inches. Establish with seed or sod.  The seed can be found at garden centers and your local Farmers Co-op.

Centipede grass has a moderate tolerance for shade.  Water requirements are moderate.  Drought tolerance is moderate.  Traffic tolerance is low.  Cold tolerance is low.  Salinity tolerance is low to moderate.  Disease potential is low to moderate.  Mow every 7 to 10 days to maintain a height of 1.5 to 2.0 inches.  Centipede is especially good for east Texas due to its tolerance for more acidic soils.  Centipede is best suited as a low maintenance lawn grass and is best established with sod since seed is slower to cover.  However, seed is available for the patient grower.

Zoysia grass has a moderate to high tolerance for shade.  Water requirements are moderate.  Drought tolerance is very good.  Traffic tolerance is moderate to high.  Cold tolerance is moderate to high.  Salinity tolerance is moderate to high.  Disease potential is low to moderate.  Mow every 5 to 10 days to maintain a height of .5 to 2.0 inches.   Sod is best for establishment.

One section of my yard is now in Zoysia grass.  It is doing great.  I have Bermuda in sunny locations.  My St. Augustine is doing much better but I will eventually replace it because it requires too much water and is prone to so many diseases.   I have a section of exposed slightly acidic soil in moderate shade with soil erosion.  I think this plot is a good candidate for Centipede grass.

It is that time of the year when we are now entering the fall season that brings cooler weather and humid, rainy conditions.  These conditions when the overnight temperatures are below 70° F and the daytime temperatures are in the 75° F to 85° F range can lead to many problems in the lawn.  Brown patch is one of the lawn diseases that becomes a real problem in our lawns during the cooler and more humid weather conditions in the fall and early winter months.  A number of popular lawn grasses are susceptible to brown patch: Berumda, Carpetgrass, Centipede, Fescue, Kentucky bluegrass, St. Augustine and Zoysia.  Other grasses may be infected as well.  Brown patch may be identified as circular or irregular shaped patches of light brown, thinned grass.  The grass may appear yellowish and have a smoke ring on the outer edge.  Leaf sheaths become rotted and a gentle pull on the leaf blade will easily separate the leaf from the runner.   Most fungicides will do an effective job if used as a preventive treatment.  Brown patch may be harder to control once the fungus is established.  The Texas A&M website (aggieturf.tamu.edu/answers4you/disease/brownpatch.html) lists some of the more effective fungicides.  There are other fungal infections that may resemble brown patch.  The same fungicide may control that problem as well.

I recently had a brown area in my lawn.  Brown areas caused by grub worms will show a browning or the appearance of a lack of water in the area.  The damage may be a small spot or cover a large area and is caused by white grub worms, the larvae of the May or June bugs.  The larvae feed one to two inches below the surface and destroy part or most of the root system of the lawn.  Damage usually appears in late July through early August.  If the damage is heavy, the sod can be easily lifted up or rolled up.  To verify that the problem is grub worm damage, dig one square foot sections to a depth of 4 inches.  Treatment with an insecticide is necessary if more than four grubs are found per square foot.  Since my lawn damage was in an area where I have had a problem with grub worms before, I treated the area with an insecticide.  The grass is already showing good signs of recovery.  If left unattended in the fall, the grub worm will survive over winter and become very active in the early spring.  By this time, the grubs have done more significant damage to the grass roots and large areas of the lawn may not survive the winter.

Cinch bug damage appears as irregular patches in sunny areas, usually along driveways, sidewalks and house foundations.  The grass first turns yellow and eventually dies and turns brown.  To identify a chinch bug infestation, remove both ends of a metal can and twist it into the grass.  Fill the can with water and a little detergent.  In a few minutes, the chinch bugs will float to the surface.  They are black with white wings folded over the body.  Treat with an insecticide that has cinch bugs listed on the label.  Read the label and carefully follow the directions when using any fungicide or insecticide.

Cool Weather Lawn Problems by Charles Bohmfalk

We are now entering the fall season that brings cooler weather and humid, rainy conditions.  Lawn diseases become a bigger problem with these conditions that are more pleasant for us.  Brown patch is one of the lawn diseases that becomes a problem in our lawns during the cooler and more humid weather conditions in the fall and early winter months when night time temperatures are below 70° F and the daytime temperatures are in the 75° F to 85° F range.  Most turf grasses are susceptible, especially St. Augustine, zoysiagrass and centipede grasses.  Brown patch doesn’t normally kill the affected grass, but it can weaken the affected grass and make it more susceptible to further damage by the approaching freezing and sometimes dry winter conditions.  Brown patch is a fungal disease problem that can easily be confused with grub worm, armyworm, sod webworm, cutworm and chinch bug damage.  Proper diagnosis is necessary to treat and remedy the problem.

Brown patch has circular to irregular shaped patches of brown or yellowing grass that is less than one foot to several feet in diameter.  The outside of the circle may have a “smoke ring” appearance that is caused by the spreading fungus.  In this area, the leaves of the grass may be easily pulled from the stolens or stems.  Inside the infected area the grass may remain green that leaves a “frog-eye” appearance.  Leaf sheaths in the infected area also become rotted and water-soaked to the point that a gentle tug of the leaf blade easily separates it from the runner.  To prevent this disease from attacking your lawn, pay close attention to your watering habits, thatch accumulation, and your nutrient management program.  Fungicides that are easily obtained at your local garden center can be used for the prevention and control of brown patch.  Read the label and carefully follow the directions when using any fungicide or insecticide.

Brown areas caused by grub worms will show a browning or the appearance of a lack of water in the area.  The damage may be a small spot or cover a large area and is caused by white grub worms, the larvae of the May or June bugs.  The larvae feed one to two inches below the surface and destroy part or most of the root system of the lawn.  Damage usually appears in late July through early August.  If the damage is heavy, the sod can be easily lifted up or rolled up.  To verify that the problem is grub worm damage, dig one square foot sections to a depth of 4 inches.  Treatment with an insecticide is necessary if more than four grubs are found per square foot.

Cinch bug damage appears as irregular patches in sunny areas, usually along driveways, sidewalks and house foundations.  The grass first turns yellow and eventually dies and then turns brown.  To identify a chinch bug infestation, remove both ends of a metal can and twist it into the grass.  Fill the can with water and a little detergent.  In a few minutes, the chinch bugs will float to the surface.  They are black with white wings folded over the body.  Treat with an insecticide that has cinch bugs listed on the label.  Read the label and carefully follow the directions when using any fungicide or insecticide.

Lawn Care by Charles Bohmfalk

Mowing is the most important part of lawn care.  A lawn should be cut to the appropriate height.  Since most of the lawns in this area are common bermuda or St. Augustine, I will address most of my comments to those grasses.  Common bermuda grass lawns should be mowed when they reach approximately 2 1/4 inches in height and mowed to a height of 1 1/2 inches.  St. Augustine and most other grasses in our area should be cut when they reach 3 inches and cut to a height of 2 inches.  Many hybrid bermuda grasses should be kept shorter.  A good rule of thumb about how much to cut is to only cut 1/3 of the total blade length at one time.  Mowing the grass too short can cause several problems.  First, shorter mowing can inhibit root growth. There is a direct relationship between blade length and root growth.  Another important function of the leaf blade length is heat insulation.  Removing too much leaf can also make the grass more easily damaged by high summer heat, and more susceptible to wear.

Mower blades should be kept sharp to insure a clean cut that will heal quickly.  Dull blades will leave grass blades jagged and torn.  Grass cut with dull mower blades may show a tan shade over the lawn.

Lawn watering is one of the most necessary and basic needs of a lawn, but is frequently done incorrectly.  Watering too often (daily in many cases) can cause the lawn to put down shallow roots.  The lawn will not be able to survive a hot, dry summer, especially with watering restrictions.  Appropriate and deep watering will encourage the grass to establish a deeper root system that will help it to survive our hot and dry summers. Wait for the lawn to tell you when to water.  Look for a few dry spots to begin to appear.  They can indicate that the time to water is near.  If it is just a small spot or a few small spots consider spot watering.  As more and larger sections of the lawn show up, it is time to water.  Another indicator that the lawn is about to wilt is when the lawn takes on a dull purplish cast and the blades begin to curl or fold, or when footprints remain after you walk across the lawn.

Different soil types require different amounts of water for a normal watering.  About 1/2 inch of water may be adequate for a soil that is high in sand.  A loam soil may need about 3/4 inch of water while a highly clay soil will require about 1 inch.  Water the lawn until the water begins to run off.   The best time to water is in the morning when it is cool and the wind is generally calmer.

Fertilizing is another important part of lawn care.  The best way to determine what to use and how much to use is to have a soil test.  Many nurseries provide the service, generally for a fee.  If a soil test is not available, apply a fertilizer with 4-6 parts nitrogen, 1 part phosphorus and 1-4 parts potassium.  A fertilizer with a 3-1-2 or 4-1-2 ratio is a good choice.  (For example a 9-3-6 or a 20-5-10 ratio.)  It should have a portion of the nitrogen listed as slow release.  Slow release nitrogen fertilizers may be difficult to identify or find.  Look for terms like sulfur-coated urea, resin-coated urea, ureaformaldahyde, isobutyliene diurea or natural organics as the slow release nitrogen portion.