When to Apply Grub Control Fertilizer to Lawns?

Timing

• The best time to apply a grub control mixed with fertilizer is between the beginning of July through mid-July. During this time, eggs have just been laid. By applying a preventive grub control product one month before eggs hatch and while they are young, you can stop some of the damage. Use a grub control product that contains 25 percent imidacloprid and 75 percent fertilizer. It is important to test your lawn for white grubs to find out the extent of your problem before applying the grub control fertilizer granules. Unless their population is high, you do not need to apply chemicals to the lawn.

Testing Your Grub Population

• Use a sharp spade to cut out samples of turf from the yard. Cut out 6-by-6-inch samples of turf and count the number of grubs in the grass and soil. Take several samples of turf out of the yard to achieve an accurate assessment. Gardeners who have two to three grubs in the samples should spray with a grub control product. Take note of the areas that have a high population of grubs and focus your efforts on these areas.

Applying the Grub Control Fertilizer

• Pour the grub control fertilizer into a drop spreader. Measure the amount that you need for the square footage of your infested areas or yard. Avoid excessive applications of fertilizers, because you will wind up burning the grass. Push the drop spreader over the yard slowly to achieve an even coverage. Go back and even out any areas where granules have accumulated. Water the lawn with 1 inch of water, so that the grub control product sinks into the soil.

Other Factors

• Reapply a regular nitrogen fertilizer in four to six weeks. If you want to apply a grub control product in the fall, use one that has an active ingredient such as carbaryl. To prevent damaging your lawn, keep the grass watered throughout the growing season so that it can withstand chemicals. However, gardeners trying to control their white grub population through cultural means should allow infested areas to dry out. Withholding water dries out white grub eggs.