Sampling for grubs is a good first step in determining whether or not your should treat. Random sample holes throughout the lawn will give you a general idea of how large the grub population might be. You can cut a square foot of turf out, pull it up and look on the soil surface and on the roots for fat, white grubs; less than six grubs per square foot can usually be masked by water and fertilizers. Populations between 10 and 15 per square foot can cause significant turf damage in September and October. Of course, populations occasionally reach 40 to 60 grubs per square foot and these levels can cause significant damage. If you find grubs you can treat your lawn with a product like Grubex in late summer or Bayer Advanced Season-Long Grub Control granules (which is time released and can be applied now). |