Sorry - my initial post didn't include the pics from this spring. Here they are.

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I'm going to post pics of current conditions, tomorrow.

Mike,

I am in zone 6b in CT, and have had significant grub damage in the past. I also have a three year old son, and like you I wanted to try an organic approach to them, but my local agricultural extension office told me that milky spore and nematodes have shown relatively poor results up here, apparently due to the temps in this zone. Since you are in zone 6 I thought to mention that, but you will probably want to look into how well those products work in your specific area rather than rely on what I was told about CT.

After looking at all of the synthetic alternatives I could find that are available to the homeowner I decided on Imidacloprid (Merit, Grubex, other brands too, very easy to find), applied on or just before July 4 every year. If you look up the toxicity (google "LD50" and "imidacloprid") and take some time to weed through the results you might reach the same comfort level I did. Which is mildly uneasy, but basically comfortable.

Unfortunately you are right that the grubs have started moving deeper and are larger and more difficult to kill now. Imidacloprid won't do it this late, it is just too weak. Dylox might, but using that stuff is like dropping a nuclear bomb, and I am not comfortable using it, and would guess you would not be either.

If you decide to go with those other products I hope they work out. I am just concerned that they won't. I let most insect and fungus problems that I get go untreated, and the grass eventually recovers. But I am vigilant about grubs, they are just too destructive to ignore IMHO.

I don't have much advice on your overseeding questions, other than to suggest that if the 50% green grass around the really dead areas is pulling up like carpet, that grass is dead too, it just doesn't know it yet, so whatever you do I wouldn't waste any time hoping it comes back, and being TTTF it won't spread much anyway.

Sorry for the downer post, but I hope something in there helps!

Paul

Hi Paul, thanks for your advice. I appreciate hearing someone else having the same issues and concerns re: use of chemicals. I also double-checked my zone and find that I am also in zone 6b. It's probably hotter here in S. Philadelphia than in CT, so I hope the organic products may work better. I did find a link from our state agricultural program (Penn State Univ.), regarding Integrated Pest Management (IPM) approaches to grubs (see the bottom of this post).

I still haven't received my neem oil in the mail, so I may also order the nemotodes so I can try both.

Yesterday I took these lawn shots - it's depressing and aggravating that I worked so hard to get it nice and then these little b##tards are ruining my lawn.

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Here is a link that might be useful: Web site - Take Control of Grubs in Your Lawn - June 2007

Hi Mike,

I read that article, thank you for the link. Just my opinion, there is a lot of important information missing from it. Like that fact that milky spore takes at least a few years to get established (even where it actually works!) for one. And, unless I missed it, that milky spore only works against japanese beetles, and none of the other beetles that create new grubs. And that certain types of nematodes only work against certain species of other beetles, and not all of them. And there is some misinformation too - no synthetic grub control that I am aware of is recommended to be applied in early spring, as Ms. Niedermeier (sp?) suggests, so her arguments against those products make no sense to me.

It is certainly possible that there is some combination of milky spore and specific nematodes that will address your problem, over time. To figure that out I think you need to either identify your major beetle populations and choose products accordingly, assuming they are available, or contact someone with a skeptic's eye on the whole thing, maybe at your local agricultural extension office. I have no problem with the IPM concept, but in practice, and just IMHO, it is populated with folks more interested in reducing overall herbicide use than with actual pest management.

/off soapbox

Call your local extension office and actually talk to someone there, with your BS meter on, keeping firmly in mind that you never want a repeat of this sort of damage again. I mean, there may be times after pesticide application that you will want your toddler off the lawn. But he can't play on dead or recently renovated grass either.

Again not meaning to move you off of the organic approach, just hoping you are getting the right information for your area in order to make an informed decision, and that you get good results no matter what you use.

Paul

Neem oil does not kill grubs. Milky spore only works on Japanese beetle grubs, not masked chafer grubs, so you'd need to know what kind of grubs you have before you use that.

Nematodes will live in the soil, as long as the soil is moist, until the soil temp (NOT air temp) gets down to 50 degrees.

I understand your concern for your child, but could you keep your child off the lawn for a couple days until the grub killer is watered into the soil? And it would need significant watering or rain to get it down in the soil to work on the grubs.

Deanna

I applied two doses of neem oil (Grub Beater) and pulled out more dead areas since my last post. I put the neem oil on the grass on a very hot day, and I hope the grubs were close to the surface to suck it in. I know it won't kill them but it's supposed to mess up their instinct to eat. Two days ago I mowed the grass, dethatched and then watered it. Today I scalped it with the bagger on (my Black and Decker mulching mower sucks I'm now convinced - it seemed to have no power and kept stalling when I had it on the lowest setting - it could be that it was dusk though and the grass may have started getting moist). Tomorrow I am going to core aerate and then overseed it. I have a bunch of compost, a few new bags of Scotts starter soil, and some peat moss. I'm going to mix it together and put it down to level out the thin areas, and then overseed. The dead areas I will put new dirt and then new seed so that the new grass is level with the existing lawn. Then I'll water 20 minutes 2x a day and pray that my lawn comes back!