Ronald Strahan, Koske, Thomas J.
Fall is not a time to do much to your Louisiana lawn – mow, remove fallen leaves and irrigate as needed. Warm-season grasses are slowing down and trying to go dormant. "We must let them do so," says LSU AgCenter horticulturist Dr. Tom Koske.
The horticulturist adds, however, that it does pay to observe your lawn. The cure for many April problems is corrective action taken the previous November.
Be aware of stresses like drought or abrasion from a spur-of-the-moment soccer game. Conditions like these damage the slow-growing fall grass, which can’t repair itself before frost shuts it down.
Also, be on alert for diseases. Several root-attacking diseases that are hard to see will weaken the lawn's ability to over-winter well. They also can kill grass before it hardens off for winter dormancy. If brown patch appears, apply fungicide to check further foliage loss.
"The threat of disease is a good reason to watch your lawn in fall, because next spring you may find dead and dying patches of grass," Koske advises, explaining, "Diseases like Spring Dead Spot develop from previous fall conditions and the type of winter we have."
Affected grass may go off-color from low temperatures but actually may be suffering from a foliar or root disease. Weak grass is more susceptible to freeze damage and weak green-up in spring. If you ignore the discolored, dying grass, the dead patch will blend in with the rest of the yard when frost hits, but what's dead in December will still be dead in April. Open areas in spring are just asking for annual weeds to come in.
By noticing what you have now, you may predict what you will see next spring. Management of problem areas requires mapping (noting) where symptoms continually appear. Are these problems on cold, north-facing, droughty slopes? In low-dished, water-soaked areas? In areas where 1 or more inches of dead thatch are? In areas of very hard, compacted soil?
Now is a good time to observe lawn areas that may need special attention this fall and next growing season. Pull a soil sample for testing if you suspect soil fertility problems, and apply lime if results recommend it.
"We can protect the grass this fall with fungicide and proper irrigation, but recovery and site repair will be done next growing season – this growing season is over," Koske says.
The LSU AgCenter and the LSU College of Agriculture