Monday, September 14, 2015

Large Patch / Worms

With all of the heavy rains, Large Patch/Brown Patch is really giving our Lowcountry grasses a hard time!  The cooler nights, lower daylight hours, and these rains have created an environment favorable for the spread of this disease.  Hopefully, you are all saving some money and have turned off your irrigation because we have had at least an inch of rain for each of the last three weeks.
If you have discolored grass this time of year, it could be Large Patch, or I am still seeing plenty of worm (fall army worm, sod web worm) activity.  You must identify what pest you have because worms are an insect which needs insecticides and Large Patch is a fungus which requires a fungicide to eradicate.
Where you have Large Patch, there is a dead area in the center that is outlined by yellow grass.  If you pull on the dead grass or the yellow grass, it will come up very easily from the runner.  At the bottom of the leaf blade you just pulled up, you will see a dark discolored area.  Large Patch is a soil borne fungus that attacks the grass at the crown of the plant.  The crown of the plant is the areas where the leaf blades go up and the roots go down.  In the dead area, you can rake up the dead blades of grass with your fingers. 
If worms are munching on your turf, the discolored areas will have half eaten leaf blades.  If you see an area in your lawn that looks like it has been mowed, but you haven’t mowed in awhile, that could be an area where worms have been feeding.  You can also see the worms or their fecal pellets in the bad grass that borders the good grass.
Moths are very evident in lawns that have worms. If you walk around your yard at dusk and see moths fly up out of your lawn, there is a very good chance you have worms on the way. Moths lay eggs. The eggs turn into the worm that eats your grass. The worms then turn into moths and the cycle continues. Moths will also hang out in flower beds. They especially seem to like Liriope (monkey grass).
Large Patch reappears in the same place every year which makes it easy to control.    Large Patch likes compacted, thatchy, wet and poorly drained areas.  Large Patch also likes yards where people run irrigation all the time regardless of rain.  If you can manage these cultural issues through aeration, de-thatching and correcting drainage, you should notice a decrease of the fungus in your yard.
Serenade is an organic fungicide that you can use to control Large Patch.  Applying Natures Blend, Crab Shell and SeaHume in these areas will increase the bio-diversity and relieve compaction.  Many of our customers have noticed a great reduction in Large Patch in the areas where they applied Natures Blend, Crab Shell and SeaHume.  Cleary’s and Disarm products systemically move into the plants and protect them from disease. 
For fungi it is best to treat before your grass gets the disease. Like the way people get a flu shot, before they get the flu. Fungicides will help afterwards to prevent further damage; however, the dead grass will not come back to life.
Sevin is a great product to control worms.  Not only will it kill the worms, but it will also kill other things in the soil that moles feed on. Bifen or Bug Blaster will work too. If you would rather go organic, Thuricide is a Bt product that will help kill the worms.  Applications every 2 weeks is not uncommon.
Always read, understand and follow product label. The product label is a Federal Law.