You will never know from year to year whether or not you will have a problem with grubs. Just because you have had problems in the past does not mean you will have problems in the future. Generally we will encourage a preventive grub treatment if a lawn is thick and lush and/or if it has an irrigation system. We tend to notice more problems with these types of lawns. Grubs feed on the roots, which causes the grass to dry out and turn brown during the hot periods of the summer. In some cases this will kill the grass plant. Animals that feed on grubs (raccoons, skunks, etc.) will tear up the lawn digging to find and eat the grubs. The ideal time to apply a preventive treatment is the last week in June through the Middle of July. Make sure the product gets watered in with at least one inch of water. This will allow the product to get down where the grubs feed.

If you do not apply a preventive grub treatment and notice grub damage later in the fall it may be too late to treat for them.  Once you notice grub damage in the fall most of the damage has been done.  If you apply a curative treatment at that point the product may not make it down to the grubs before the grubs move deeper into the soil to overwinter.  The best thing to do if you notice grub damage is to start watering the lawn and apply a light application of fertilizer.  This will provide the plant the moisture it needs to survive reducing loss from drying out.  It also provides the plants nutrients so it can start to regenerate new roots.

HOW MANY GRUBS IS TOO MANY?

We often get several calls a year from people that find grubs in their yard as they are digging in the yard or working in the garden.  There are generally always going to be grubs around in the lawn.  They are the larval form of the beetles you see flying around the street lights during those summer evenings.  It ends up coming down to how many grubs are feeding and how dry are the weather conditions.  Our rule of thumb is that if you find more than 8-10 grubs in a 1 foot by 1 foot square of grass you may have damage.  If conditions are dry it would take fewer grubs feeding on the roots to cause the plant to die. 

If you are concerned about whether or not you may have grubs, here a re a few things you can do to check.
-Damage generally appears as mottled brown patches.  Is is generally not in rings or perfect circles.
-The grass will generally be easier to peel back (almost like carpet)  Grubs feed on the roots.
-We see damage on all lawn types but it is more easily seen in thick lawns and irrigated lawns.
-Look for grubs in the top inch or two of soil when you dig down.

If you are concerned you may have grubs feel free to call us at 515-382-8830 to have one of our turf specialists come and look at your lawn.