Grubs have plagued area lawns since long before I entered the tree and landscape business. However, they are now better controlled thanks to more people taking a keen interest in their lawns.
Like most bugs, grubs are adventitious creatures. They go for the easiest meal, and that’s usually the weakest lawns. Good, thick, healthy turfgrass is more than a single crop of grubs can devour. That being said, it’s still imperative that everyone check their lawns for grub larvae, beginning in late August. If one property owner in a neighborhood is lax, control for the whole neighborhood is compromised.
What are grubs? Remember those big, brown, beetle-like insects that were flying around in June and early July, hitting windows and screens? Those were adult European chafer and Japanese beetles. Grubs are the immature stage of those two pests.
After mating, the chafer or beetle lays its eggs in sod. When the grubs hatch, they start migrating down into the soil while feasting on tender turfgrass roots. Needless to say, this kills the turfgrass plants and they turn brown. This is the best time to control grubs. They are still small, living and feeding near the surface, and are more susceptible to control material.
To determine if you have grubs, and how many, cut several one square foot pieces of green sod and roll it back. Count the number of grubs. If there are six or fewer, they are not present in sufficient concentrations to really harm your lawn. If there are seven or more, you should either spread grub killer on the lawn or call us to do it.
As the temperatures fall, the white, crescent-shaped grubs burrow deeper into the soil until spring. When they return to just below the surface in spring, they’re about double the size and ready for one last feast before pupating and morphing into adults. We don’t recommend treating in spring, unless your yard is overrun by grubs.
If you have brown grass that doesn’t re-green after grub treatment, rake out the dead grass. If the area is small, the healthy grass will fill in the open space over time. If it’s larger, you’ll have to re-seed. Be judicious with fertilization, provide sufficient water and mow high.
It may not be possible to eradicate grubs, but you can win the battle in your own yard. If you have healthy turfgrass, you can keep them under control by following the steps presented above. Next season, you may want to consider a Birchcrest lawncare program and leave the diagnosis and treatment up to our professionals.