Hi Brizzy, Yes, I think the advice to "prevent" (meaning to kill the young ones) rather than kill (the established ones) is excellent, but I think someone gave you the wrong timing. These things hatch in late summer, and then you see the damage in fall and, to a lesser extent, spring. By the time you notice the damage in fall they have started migrating deeper into the soil and have stopped feeding on the grass roots, so it becomes very hard to kill them then, and besides, most of the damage has already been done so killing them is kind of pointless except maybe for the soothing balm of vengeance... They can do some additional damage in the spring when they come back up to feed a little more before turning into beetles and flying away, but spring damage is nothing like fall damage, and anyway at this time they are monster grubs and very hard to kill. The junkyard dog with the spiked collar. Just walk away... So the best time to get them is when they have just hatched, are tiny and vulnerable, and near the top of the soil. That is late summer, and that is what the "preventatives" like imidacloprid were designed to do. They call it "season long" control because if you kill them then, there just won't be any fall or spring damage because there won't be any grubs, or at least they will be few enough for the grass to tolerate.

Why did you mow at the lowest setting? Was that in prep for seeding? Dig around in the surface of the soil. You are going to take a census of the grubs. If you have fewer than 12 grubs per square feet, then the lawn should survive this year's grub attack. More than a dozen grubs and you should do something. Do you already see damage or do you just see the grubs? If damaged, can you post pictures? Timing for insecticide, seed, and fertilizer depends on what you use. If you use organic grub killers like beneficial nematodes or spinosad, you can apply seed the same day. Those two products cause a disease in the grubs and they stop feeding. If you use a chemical insecticide, then read the label regarding new seed. Timing for new seed is just right. Now is the time.

My Master Gardener agent teaches that the best time to treat the lawn for Grubs is in Mid August, when the new crop of eggs have hatched and they are most suseptible to the effects of the grub killer. He says the grubs are too mature in the spring and the grub killer is mostly ineffective if applied then. My lawn seems to agree with him. Here's What Ohio State recommends and they seem to agree with Indiana. "Chemical Controls - Insecticides The grubs are best controlled when they are small and actively feeding near the soil surface, usually late July to mid-August. However, with the development of new grub control chemistry (e.g., imidacloprid [Merit] and halofenozide [MACH2]), applications in June and July have sufficient residual activity to kill the new grub populations as they come to the soil surface in late July through August. Control of grubs in late-fall or early-spring is difficult, at best, because the grubs are large and may not be feeding. Only trichlorfon (Dylox) and carbaryl (Sevin) formulations are available for such rescue treatments. The key to good control is to make an even application and water thoroughly." Taken from The Ohio State University Extension Fact Sheet Here is a link that might be useful: Control of Japanese Beetle Adults and Grubs in Home Lawns

Sorry. This will be a long one. It always is with me. (blushing) I'm with the OP on this one. Even if no one but me ever saw my lawn, I would want it to be dark, rich green GRASS...and nothing else. (I'm known for wanting everything to be beautiful. I'm also a bit of a home body, and enjoy spending time in my yard. Many guests have remarked that, no matter where they look (on my property), there's always something beautiful. I'm always taken aback by those comments, since while that was MY goal, I never expected others to pick up on it.) Case in point about the intentional act of putting down grass, and not other (lower maintenance) plants. I own a small, remote island. I made the decision to create a lawn area and, once you include the slow-moving barge fees (3 days to get from its port to the island), labour, equipment, and materials, that lawn cost me $14,000. That obviously begs the question, why, on earth, would anyone spend a nickel putting in expensive, high-maintenance grass, only to let it be taken over by clover and other weeds??? My husband and I recently purchased a 19th century farmhouse in need of roof-to-foundation renovation. As such, I inherited a lawn that is EASILY 70% weeds, including clover so thoroughly interwoven, it would be impossible to pull by hand. I pride myself on my beautiful lawns and gardens, and can spend/have sent hours, each day, ensuring everything is healthy and how I want it. At my last home, I developed a bit of a reputation for being out weeding my lawn by hand for hours, plus how awesome my expansive lawn was. My point is, I want my lawn and gardens to be a certain way; plant the plants I want; pull the plants I don't want; unafraid to put-in the effort to achieve that. I prefer not to use any kinds of "chemicals", other than the ammonia and mild soap I include in my homemade fertilizer recipe. (My last home was a beach house. So, that only reinforced my desire to go chemical-free.) But this new-to-me house is demoralizing me...practically to the point of tears, much of it because of the state of the (laughing) "landscaping". Sure, mowing can cut off 60% of the sea of clover flowers that make my lawn look white (or dying...can't decide which). But there are still lower flowers that seem to sprout up to full height within the next 24hrs after a mow. These flowers last from late spring to fall. In short, I'm plagued by clover flowers throughout the entire season I want my lawn to look great. It's just such a shame the previous owners didn't nip the clover in the bud, when each plant was jut a little, round cluster. I love catching them early, knowing I've stopped additional infiltration. But I'm helpless, overall. Looks like I'll have to replace the entire lawn; start from scratch; do what the previous owners SHOULD have done, and pulled weeds when I first see them. I'm not really buying the whole "benefits of clover" thing, amidst a grass lawn. If I wanted a clover lawn, I would plant a clover lawn. Putting down and maintaining grass is an expense in time and resources. Clover is virtually free (since it shows up on the wind), and is seemingly mantenance-free. Since most sod and grass seed are sold with some guarantee of being weed- (and clover-) free, I just don't believe that most people who spend the money and effort to put in a grass lawn, are okay with losing any percentage of it to other, invasive, undesirable plants. I kind of liken it to suggesting that a Ferrari owner would be okay with someone switching it with a Cavalier, and just saying, 'They both get me from point A to point B, so I don't mind.' I can fully envision putting in other kinds of ground cover, and have considered it at past properties. Not being my first rodeo, I already have substantial plans to reduce the amount of lawn area, and increase planting beds. But much of this current property begs for a beautiful, thick, dark green lawn...of grass. No dandelions. No clover, but particularly no clover flowers. (I'd be more okay with clover, if not for the flowers.) The desperation was so great, I did something I thought I'd never do, and tried the iron-based WEED-B-GONE product. (Harsh, chemical herbicides have been banned in my area for years...resulting in public parks being taken over by weeds, for the most part. It's such a shame, in the sense that a healthy, well-maintained lawn is not only beautiful, but fantastic underfoot.) That is really my philosophy, beyond the aesthetic. A lawn should be cool, soft, and luxurious under bare feet. Weeds, even overgrown grass, also tend to make barefoot walking less than a joy. So far, I haven't found a way to get rid of mats of clover. The WEED-B-GONE did nothing I could notice. I'm at my rope's end on ths matter, and likely will have to pull up the entire lawn, to put down new, almost-weed-free sod, where I can physically manage pulling individual weeds as they appear. I guess I'd plead with people to pull unwanted clover plants when they're small... if not for yourself, then for the next property owner. Sure, it means time, every day, or every few days, combing the lawn, looking for weeds. Yes, it can be back-breaking and time-consuming. But that grass lawn didn't get there by accident. A grass lawn is intentional.