Lawns damaged by white grubs

White grubs are the larval form of June beetles. They prefer lawns but can also be a garden problem. They feed underground and will feed heavily on grass roots in the lawn. The grass will turn brown and die where they feed. Their damage shows up most as the weather gets hot and dry since the grass roots are severely shortened and don’t take up enough water. If a person grabs the grass tops and lifts, it will come out with little or no effort due to the lack of roots. Another sign of the grubs is extensive digging in the dead areas. This is an animal or animals digging the white grubs up and eating them. Skunks, raccoons, and sometimes squirrels will do this. Large areas can be uprooted in just one night by a female skunk or raccoon and their young.

White Grubs have a three-year life cycle. They hatch in year one, feed lightly, and go deep into the soil in the fall and overwinter. The second year will be when most damage is seen as they feed all summer long and grow to about one-inch long. They are white with a black shiny head and will curl into the shape of the letter “C” when dug up. Late in the summer of the second year they will again go deep into the soil and overwinter. The third year they will again feed lightly on roots and then pupate. The following year adults June beetles will emerge to start the cycle over again.

There are a number of granular white grub insecticides sold which can be used to help control them. It is recommended to be applied before they begin their heavy feeding. This would make May and June as the best months to apply the insecticide granules. Since there are multi-year growth stages of the white grubs, and adults from other areas laying eggs, plans should be made to treat the lawn for two to three years to get the best control. Read and follow the label directions. This is important to apply correctly to get the best grub control and still be safest for people and pets.

Another factor which may be a contributing factor to having them in particular yards or areas is lights on at night. The adult June beetles are attracted to light at night. Yard lights and porch lights will attract the adults to an area. It is more likely that the beetles will then lay their eggs in the lawns and gardens close to the lights.

Blossom end rot reminder

A reminder that Blossom End Rot of tomatoes and other garden vegetables is caused by a lack of calcium and not by a disease organism. And the reason the plant isn’t getting enough calcium is that it is not getting enough water. The water carries the calcium to the plant. Keep plants watered, mulch around them, and don’t hoe or till close to the plant to protect feeder roots close to the surface. This combination of practices should prevent blossom end rot.

Ken Eraas is horticulture assistant with NDSU Extension Service/Ward County. He can be reached at kendell.eraas @ndsu.edu.

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