|In late August of last year, after an extremely hot and dry summer, a much needed shower was followed by an unusually large number of small mounds (castings I assume) appearing on some of the sparser areas of lawn. In a matter of days they covered the ground completely and appeared to be feasting on the bermuda. The leaf was gone leaving bare runners which eventually died in most of the back lawn. I just yesterday noticed the small piles appearing again.
|A possible explanation is that you had some worm casting piles, along with another turf pest called the armyworm, which was very bad last year in Texas. When these pests first appear, spray the turf with a product containing B.t. which is labeled for turf application. Repeat the sprays twice more a week apart and the pests should be under control.
You may also be seeing the casting piles from a species of earthworm often seen in the eastern parts of Texas that grows to about an inch long and often occurs in huge numbers. Their casting piles become literally side by side and their high levels of activity can cover the turf leaves with soil, smothering it. The ground often becomes very soft and spongy to walk on. There is no labeled control product and most people simply wash the castings off the turf causing them to settle back into the soil. This eliminates the threat to the turf. These worms tend to come in cycles so you only occasionally see them in numbers high enough to warrant action.