If you’re digging in the garden or removing sod, you may encounter a creamy white, worm-like creature with a dark head and tail. If it keeps curling into a C-shape and has 6 legs, that creature is most likely a grub or a grub worm.

Grubs are the larvae of beetles. The most common grub in north Texas is the June beetle (Phyllophaga species) larva. Other names for June beetles include June Bug, May beetle and May bug.

Grubs feed on the roots of plants just below the surface. They prefer the roots of turf grasses, but also eat the roots of other newly germinated plants. High numbers of grubs feeding in your soil can kill turf in a short time. Grub-damaged turf can be rolled up like a rug. Grubs can also leave seedlings or young garden transplants lying on the ground, having been cut at the base of the stem by the grub worms.

Grub sightings peak from April through September. Most adults emerge between the end of May and early July in North Texas. They retreat deeper into the ground during winter for protection. Homeowners may not even realize they have grubs in their landscape until they wake up and find damage caused by hungry armadillos rooting into the soil to find their grubworm dinner.

Anyone concerned about grub damage can spot check their property by digging square-foot holes about six inches deep in several locations. If there are fewer than five grubs per square foot, they are unlikely to cause significant harm to plants or turf grasses. Low numbers may even benefit plants by improving soil aeration and permeability as they burrow. Some turf types can tolerate up to 15-20 grubs per square foot if the moisture and light requirements for them are met. 

Integrated Pest Management (IPM) strategies are the best options to control grubs, allowing for the least environmental harm while protecting turf and plants. IPM methods are generally recognized as safe (GRAS) to use in food-growing spaces and provide localized control. Grub infestations tend to be in small areas, allowing efficient application of IPM. Some people smash or drown grubs as they find them. Others gather grubs and place them in a feeder or a shallow pan for birds, toads, or lizards. Some choose to carefully follow directions to apply a specific beneficial nematode, Heterorhabditis bacteriophora, to kill grubs. Providing a welcoming environment for scoliid wasps that lay eggs inside the grubs, which feed their larvae, helps limit grub numbers, too.

Correctly timing IPM or the application of other grub controls is critical. Chemical controls are most susceptible to early larval stages. Gardeners choosing chemical grub control have better success by applying a chemical control about five weeks after the peak June bug emergence.  

Resources

“Integrated Pest Management” Gardening Basics Series, Denton County Master Gardeners Association

https://www.dcmga.com/garden-basics-integrated-pest-management-ipm/

Grubworms” Gardening Basics Series, Denton County Master Gardeners Association (accessed 11 January 2025)

www.dcmga.com/wp-content/uploads/docs/garden-basics-solve/gb-grubworms.pdf

Happy Gardening!

The Denton County Master Gardener Association