Grubs are difficult to deal with. Often you don’t even know you have a problem with grubs until it is too late. Not all lawns with grubs need grub control. However, once a lawn reaches a critical population, grubs can start to damage you lawn. Lawn grubs or white grubs come from beetle larvae. You can typically find these grubs in lawn during the late spring and early summer as well as in the fall. The most notorious lawn grub worms of these groups are Japanese Beetles, Masked Chafers, and Asiatic and June Beetles. The June Beetles do most of their damage during the early summer, but the Japanese Beetles damage you lawn in the fall.
In June and July, these larva turn into adult beetles. They mate, and then lay their eggs back into the soil. In the early fall, the larva lay their eggs in the soil. Before it gets too cold, the grub worms burrow themselves 6 to 8 inches into the soil. They emerge in the early spring as larva and grow very fast as they eat your lawn. If you are going to apply white grub control, it is important to find them as early as possible because often, you don’t know you have them until it is too late. Most of the time, you want to apply grub control in the late spring or in the fall. And most of the time, the white grubs do not kill the lawn directly, but they eat the tap roots. So when conditions of lawn stress or mild drought take place, these become fatal to a lawn. One or two lawn grubs in your lawn won’t do any damage, but when you have 8-10 larva in a twelve inch space, they can really do a lot of damage. Adult beetles do not damage grass very much, but instead eat ornamental plants and lay eggs back into the soil.
How Do You Know if You Need White Grub Control?
A good early indicator that you have a lawn grub problem is you may see a lot of holes in your lawn from birds or gophers feasting on these insects. Once white lawn grubs have been through an area, the grass turf will start to look unhealthy and appear in patches. Grubs in lawn can do a lot of damage by eating the grass and the grass-roots. As it starts to get hotter, you will start to notice that they are doing more and more damage. Grub control is difficult, if grubs are partially protected by the thatch layer in your lawn and the depth to which they live under the soil. It;s best to use a long-lasting pesticide to get rid of lawn grubs. Learn about organic grub control.
What Do White Lawn Grubs in Lawn Look Like?
White grubs are between ½ inch and 3/4 inch, although they are a little smaller in the early spring. White grubs typically live two inches under the surface of the soil. The damage caused by them will leave you with dry wilted grass with a few green patches. The damage will be most noticeable in the areas of the lawn that are the least healthy, and the areas of grass with the greatest concentration of these grubs. This website is all about helping you kill, control, and get rid of your white grubs. We have a page dedicated to Japanese Beetles, June Beetles and Masked Chafer. (Sometimes you can cut down on the chances of getting insect infestations by regularly thatching and lawn aeration).
White Grub Worms and Cutworms: Five FAQs
Q. What is the difference between white grubs and cutworms? A. Cutworms are moth larvae and white grubs are beetle larvae. Cutworms are usually a little longer (1-2 inches) than these grubs (1/2-1 inch long). White grubs are white (hence the name) while cutworms are brown or tan-colored.
Q. How do grubs in lawn affect the grass? A. Both cutworms and white grubs live in the thatch layer of the lawn during the spring and summer. This spongy layer on the soil’s surface protects them and allows them access to food and water. White grubs eat the grass-roots, causing the lawn to wilt and then dry out. This leaves the grass more likely to die when stressed, such as during heat spells and droughts. Cutworms eat the blades of the grass, killing the top first.
Q. How can I tell if I have a serious problem with Grubs in the Lawn? A. A great way to spot it early is to notice if birds are putting a lot of holes into the ground, looking for these grubs to eat. Gophers will also eat them. The grass will start looking worse too, but then the problem is getting pretty bad, and wilted and dry grass can have other causes. You also know if you have white grubs in the lawn if it starts to turn yellow for no apparent reason. Also, if you can pull the grass out of the lawn very easily, it is because the white lawn grubs have eaten through the roots of the grass plant. One great way to test is to cut out a 12 by 12 inch square in your lawn. If you have more than 7 to 10 grubs per square ft., it could be fatal to your lawn and you should have your lawn treated. If you only find one or two white grubs, then it is unlikely you will even need to use grub control to get rid of them.
Q. What should I do about white lawn grubs and cutworms? A. The type of lawn grub control you use is very important. A long-lasting pesticide is best for both of these pests. Since cutworms are the most active at night, apply a contact herbicide just before it gets dark. Once they ingest the pesticide with the grass, they will die. Since white grubs burrow deeper into the ground (6” or more) in the fall and stay there through the winter, it is best to use a pesticide for them in the spring and summer months. It may take more than one application to solve the issue.
Q. Can Grub Worms Really Ruin My Lawn? A. Yes, Grub worms eat roots of your grass. When there are only a few in your lawn, they don’t do a lot of damage and most of it is self-repaired. When there are a lot of grub worms, the damage is much more extensive. Minor damage to your lawn is fixed by power raking and overseeding your lawn, but if the damage is extensive, you may want to rent a sod cutter to tear out your lawn and learn how to lay sod. It is best to treat lawn grubs right away with grub control or by organic means, to prevent them from destroying your lawn.