White Grubs in Georgia Lawns and Garden Beds: When to Act

The plump, C-shaped larvae found in the soil are often beetle grubs. They feed below ground, but their presence alone does not prove they caused a struggling lawn or perennial. Check moisture, roots, and the pattern of decline before deciding to treat.

Check the lawn in several spots

Lift a roughly one-square-foot flap of turf at the edge of damaged grass and count the grubs in the upper few inches of soil. Repeat in several places and average the counts. Look for turf that feels loose or lifts easily because roots have been eaten. UGA Extension notes that the level at which treatment may be warranted varies with irrigation and lawn conditions.

• Brown turf with moist soil and missing roots deserves a closer look
• A few grubs beneath otherwise healthy turf call for monitoring
• Check nearby healthy turf too, so one digging spot does not drive the decision

What about hostas, ferns, and other beds?

When grubs turn up in every planting hole, note how many you find and whether plants are wilting despite adequate moisture or have damaged roots. The lawn sampling thresholds do not transfer directly to mixed planting beds. Hand-pick grubs exposed during planting and watch the plants before considering any broad treatment.

Timing and treatment

Late summer and early fall are useful times to scout while many grubs are feeding near the surface. Preventive and curative products have different timing, and a turf product is not automatically labeled for ornamental beds. Identify the pest, read the exact product label for the site and plants, and follow its watering directions. A local Extension office can help confirm an uncertain identification.

For a bed with many grubs and plants showing root damage, document what you find now and recheck in a week or two. That gives you a sound reason to act, rather than treating every part of the landscape on sight.