How often should you treat your lawn for grubs?

Why bother

Grubs eat the roots, then the lawn peels up like a rug. A thorough-tier job. Skippable when life's busy, worth it when it isn't.

Why it's a range

Once a year is the sensible reminder, but treating is optional. Most lawns don't have enough grubs to bother, and healthy turf shrugs off a fair few. If last summer brought no patches and no diggers, you can skip the bag and just keep watching. Where Japanese beetles or European chafers are thick, once a year is cheap insurance.

What the job involves

1. Time it before the eggs hatch. Standard preventives (imidacloprid, clothianidin) go down late May through early July; a chlorantraniliprole product like Acelepryn goes down earlier, April to May, since it's slower to move through the soil.
2. Spread the granules evenly across the whole lawn with a broadcast spreader at the bag's rate. This isn't a spot job, the beetles lay eggs anywhere.
3. Water it in straight after with about half an inch. The active ingredient has to wash down to the root zone where the grubs feed; left sitting on top it does nothing.
4. Watch through late summer for wilting or browning patches and check them. Healthy turf tolerates plenty of grubs, so only escalate to a curative treatment if real damage shows.

Do it yourself, or pay someone?

Yourself, easily. A ~$59 bag of something like Scotts GrubEx covers 10,000 sq ft, goes down once with a broadcast spreader, and gets watered in. That's the whole job. A pro preventive runs roughly $75-$100 for a typical lawn, often folded into a lawn-care plan. Hire out only if you don't own a spreader or you want it bundled into a full-service program.

What skipping it costs

$400-$7,500 (skip cost: ~$400-$2,000 to corrective-treat plus slice-seed light damage; $4,500-$7,500 to renovate a destroyed ~5,000 sq ft lawn). Treatment itself is cheap by comparison: ~$75-$100 professional preventive, or a ~$59 bag of GrubEx DIY. Grubs feed on the grass roots through late summer, and once the roots are gone the turf dies in patches that peel up like a rug. Then the skunks and raccoons come digging for the grubs and finish the job. Light damage means a corrective treatment and slice-seeding the bare spots. A lawn chewed to the dirt means reseeding or sod, which is where the thousands come in.

Signs it's overdue

• Brown or wilting patches in late summer that don't green up after watering, and turf that lifts away easily like a loose carpet because the roots underneath have been chewed off.
• Skunks, raccoons, crows or moles digging up or rolling back sections of the lawn at night, hunting the grubs.
• A spongy, soft feel underfoot, or more than about 10 white C-shaped grubs per square foot when you peel back a flap of sod.

When to start thinking about it

Give yourself about 14 days' notice. That's when Grumpty starts grumbling, so it doesn't land on you the day it's due. Mark it done and Grumpty sets the next one, every 12 months, so you can go back to forgetting it exists.

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