Symptoms of Grub Damage

• Skunk leave 2- to 3-inch torn-up divets in the lawn looking for grubs.Tom Brakefield/Stockbyte/Getty Images
  
  Grubs cause their damage by eating the roots of turf. In these areas the affected turf turns brown and can easily be rolled up as there is no root system to anchor it to the ground. If untreated these areas continue to grow in size. The presence of animals digging in the lawns, especially skunks, can indicate a presence of grubs as these animals tear up turf looking to eat them.
  
  

Chemical Grub Control

• If rain is not expected within 24 hours, applications of grub control should be watered in.Digital Vision./Digital Vision/Getty Images
  
  If the population of grubs necessitates chemical control, be sure to apply at the appropriate time and that the lawn area is properly irrigated after the application. Grub control products that claim they do not need to be watered in can lose some of their efficacy, as the UV rays from the sun begin to start breaking down the chemicals as they lay on top of the grass. Most grub control products should be applied when the grubs are young and more susceptible to chemicals, during the late summer and early fall.
  
  

Organic Grub Control

• White grubs are most often the larvae of the Japanese beetle.Jupiterimages/Photos.com/Getty Images
  
  For organic control of a grub problem, the lawn needs to become inhospitable to the pests. Adult beetles that lay the eggs which become grubs look for healthy turf in full sun. Introducing more shade to the lawn with trees will help to reduce the incidence of grubs. Withholding irrigation during June and July will also reduce the attractiveness of your lawn to the egg-laying beetles.
  
  

Proper Care

• Old-fashioned reel mowers are best for warm-season lawns such as zoysia.Jupiterimages/BananaStock/Getty Images
  
  The best way to mitigate grub damage is to maintain your zoysia lawn with proper care. Make sure to mow frequently and often. Zoysia responds best to being cut down to between 1 and 2 inches regularly with a reel-type mower. Apply fertilizer at a rate of 2 pounds of nitrogen per 1000 square feet of lawn area per year. Apply a weed killer as needed, although established zoysia lawns can out-compete most weed species.