Lawn Issues: Fungus/disease and watering practice

Asked June 6, 2015, 5:21 PM EDT

I have long had a fungus/lawn disease problem with my lawn.... aggravated this year, I think,by an unwise decision to fertilize in March. (TurfTrust) Lawn looks great until heat and humidity arrive, and then the lawn goes to hell. This year, I used a highly recommended fungicide, Headway-G by Syngenta. The instructions say I should "...avoid alternation with other Qols, such as pyraclostrobin and trifloxystrobin or other DMIs such as triadimefon, fenarimol, and myclobutinil." Can you identify any commercially available fungicides that does not have those ingredients? All very Greek to me. Watering my lawn: I'm told that my lawn (tall fescue) needs an inch of water a week. Better to give it half an inch twice a week, or better for the roots to give it one inch at a time, once a week. And what if it really gets hot...... say in the nineties all week with no rain. Is one inch still enough. If not, how much more. Very much appreciate your help. Tim O'Brien

Montgomery County Maryland

1 Response

You did not mention the fungus that you are dealing with on your lawn. In our experience, lawns that are troubled by fungus tend to be over managed such as overfertilizing and over watering.
Turf type tall fescue is the most disease and drought resistant grass for our area. It grows best in the cool seasons of spring and fall and tends to go dormant in the summer. Tall fescue can be susceptible to brown patch, a fungal disease in the summer months. This disease loves heat, moisture, and humidity. Usually With a return to cool weather in the fall the turf tends to rebound. If not, then some seeding is recommended for bare spots and to thicken the turf. Fall fertilization is recommended.

We do not recommend fungicides and watering established tall fescue lawns.
Watering is recommended for new lawns, overseeding, and sod establishment.

Basically, a lawn care schedule for your lawn consists of testing your soil every 3-4 years for pH, liming, and nutrient deficiencies; type of grass seed to sow; overseeding & renovation; mowing at the proper height; leaving the grass clippings on the lawn after mowing; identifying and managing weeds as they are actively growing; and fertilizing in the fall for cool season grasses. (You should be aware that Maryland now has a lawn fertilizer law. This also applies to commercial companies.

Look at our Turfgrass Maintenance Calendar for lawns. This calendar offers monthly lawn care steps as well as a fertilization schedule Also, look at the lawn section on our website for more information as well as publications.