Question
Thanks for the response. To fill in some details - I am growing in full sun. Other than milky spore how do I add nature predators and microbes to the soil? For thatch remover I used a machine that helped lift the thatch up and then I removed by racking. I do not apply weed killer I pull or spot spray if an area is bad. I do have some crab grass to deal with - any suggestions, does spring crab grass control also kill the microbes? My over thatch was due to dead areas of grass from the grub problem.

Thanks, Bob
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Followup To

Question -
I live in the south eastern PA area. I have been trying to revive my lawn for three years. The grass type is unknown, very thin and wispy. I have had 2 bad years with grubs. I just completed using a thatch remover and I would like to have a suggetion on TLC for the lawn including grub control and over seeding. Thankyou.

Answer -
Hello Bob, I have to tell you how much I admire the tenacity of some people when it comes to sweating it out for a good healthy lawn.

Thin and wispy grass sounds like a possible Bluegrass cultivar - can you confirm that you are growing your lawn in full sun, without trees or other shade source?  

It is much easier to grow grass when you have the right amount of sun.  Shade is another matter.  And you might need a different grass.

Grubs do not thrive in healthy soil, Bob.  

Reason being, there are natural predators that keep Grubs down to realllllly low numbers - if you don't kill the predators.  

Grub killer that you buy in the store will kill one season of Grubs, but it will wipe out all the natural predators, and the next season, they come back to Grub-friendly soil.  Then you're in trouble.

So you see it's really important to stop using those bags of grub killer, weed killer (which you did not mention but all symptoms point to at least occasional application of something like Weed And Feed, no?), and thatch killer.

Your soil may be a high clay content soil - lots of clay in your neighborhood?  That's a good thing.  It's packed with minerals and vitamins to grow terrific grass.  All you gotta do is stop killing all the microbes in the soil that make it healthy.

Start with a little Rototilling.  Not too much.  Just enough to break up the clay.  You want to keep as much of the soil intact, as hard as it may be, to protect the tilth you have.

Till in a VERY generous amount of organic matter.  Since it's autumn around the corner, you're in luck - leaves are perfect, along with grass clippings (which you may have to get from the neighbors), humus, kitchen compost and whatever manure you can dig up at the garden center.  

The plan here is to make the Earthworms under your compacted clay soil happy.  They will quickly transform your hardpan into beautiful, rich earth that will grow beautiful, green grass.

Pull up weeds that you happen to notice (since you have been applying weedkiller, I don't expect that is necessary) and throw down a healthy amount of Pelletized Lime to bring up the pH to a grass friendly level.  

These steps will mark the beginning of your new relationship with your lawn.

If you see grubs down there, keep a stiff upper lip, Bob.

For one thing, you don't have any grass to feed them, so you have nothing to lose.

For another, if you leave your soil alone and add that Humus and Compost that we mentioned above, you will be creating the perfect environment for those grub-killing pathogens in the soil.  

Sure, it may even take a season or two, sure.  Just wait and see.

There are lots of remedies for Grubs.  First, let's just get it out of the way to say that Grubs are the larvae - ugly little curly gray and white hatched babies - of beetles.  Beetles lay their eggs in the soil.  When the eggs hatch, the larvae live in the soil and eat grass roots.  If there are a few larvae, the grass roots are not really damaged.  The damage is so small that your grass does not feel any pain and there are no symptoms.

But if you watched some of those TV commercials, you'd think they were some kind of weapons of mass destruction, a threat to all mankind.  They're not.  They're tiny little white wiggly grubs.  In healthy soil, there's billions of bacteria and tiny organisms that absolutely LOVE the taste of beetle larvae.  They LOVE to eat grubs!

So we don't want to do anything to hurt those bacteria and grub-loving organisms.

And by the way, any grubs that escape the bacteria and organisms become BIRD and SQUIRREL FOOD.  Haven't you noticed how birds love to eat breakfast there?

They are eating grubs!  Robins GO CRAZY for grubs.

If you really think you must put something down, get yourself to Home Depot and pick up one of those blue cans of Milky Spore Disease.  This is actually a container of Fungus that makes grubs very sick!  If they are sick, they don't turn into beetles, and they don't lay eggs for making more grubs.  I sprinkled the Milky Spore Disease powder on my lawn a few years ago and now, 3 years later, I have very
few Beetles.

According to the University of Illinois Extension ewsletter, destroying grubs does not really lower the number of beetles the next year. As they explain it, the beetles fly all over the neighborhood. You can't fence them out.  So you just want to keep them under control.  And you can do that if you don't upset the balance of Nature.

Any Earthworms down there?  

Earthworms are Nature's underground soil builders.  If your soil is compacted, Earthworms will till it - gently - and build rich, thoroughly wonderful dirt for your grass.  They feast on microbes in healthy soil.  Earthworms are generally hailed by scientists as "the largest contributors to soil fauna biomass and key players in organic matter decomposition and soil macropore development."

You need high levels of Organics to support a healthy Earthworm population.  

And you want to avoid damaging that population by avoiding anything that will reduce the microbes and other factors that Earthworms count on - excessive disturbance of soil by rototilling, for example, or pesticides.

Night Crawlers (Lumbricus terrestris) take on the work of moving Organic matter through soil.  When you do less tilling, Organic matter collects at the soil surface, and Earthworms multiply.  

Since we're moving into autumn now, you also have the perfect opportunity to add microbe-friendly things like dead leaves and grass clippings.  The more microbes, the happier the Earthworms.

I'm not sure what thatch remove you used but I have to say again, healthy grass and soil do not get all thatched up.

Thatch is happily consumed and digested by Earthworms and microbes.  When they're finished, you have rich, healthy soil, free of chemicals, ready to build up your grass.

One of my favorite Organic Grass websites, Dirtworks
(www.dirtworks.net/Lawnfert.html_), puts it this way:

"Benefits of a biologically active soil include soil aggregation, thatch reduction, more efficient release of available plant nutrients, improved soil atmospheric respiration, systemic acquired disease resistance, antioxidant hormone production, improved water infiltration, increased water and oxygen holding capacity, deeper and more extensive turf roots, mycorrhizal associations, reduced soil compaction, and improved turf density with consequent weed suppression."

Sort of takes your breath away, don't it, Bob?

Just do everything you can to keep the Earthworms happy, and lay on the Compost.  Watch the pH (you don't want your soil pH lower than 6.5, which is the perfect pH for grass).

Earthworms will aerate. Birds will eat all creepy crawlers, including grubs. The sun will shine.  Life will be good.

Any questions?  Sorry for the long answer - but you sound like you're serious about your grass, and tha'ts what I'm here for.

Answer
Well Bob, That is TERRIFIC news - I have to tell you I am pleased as punch that you did not pour on the pesticides and the weedkillers.  Much to your credit, I stand corrected.

This means there will be no residual pesticide problem, at least that we know of, killing anything good you want to do for your grass.

Let's go down the list here.

Starting with your Thatch.

There is a very smart man named Robert Donnan - and No, I am not Robert Donnan - who runs a very good landscaping business in your part of the world, Pennsylvania.  And he has a website - with some very good pictures of a thatch problem.  In fact, I almost wonder if Mr. Donnan went over to your house and took a picture of your lawn (www.donnan.com/thatch.htm).

Granted, this photo depicts one doozey of a thatch problem.  But Mr. Donnan has a very good point.  He explains very clearly that over-fertilizing your Kentucky Bluegrass, which is easy to do because everyone wants to feed Bluegrass, will lead to excessive grass growth, which leads to thatch.  And thatch is a pleasant place to be if you're a grub.

You have a Thatch Problem with Bluegrass if the thatch is more than a half inch thick.  The lawn in the Doonan photo is practically a thatch blanket.  Thatched Blugrass just a half inch thick spells trouble.

Of course, there are several causes of thick thatch.  But this one on the Donnan Landscaping website looks so much like your thatch-and-grubs lawn, it's spooky.  The general theory is that grubs

Which came first, the grubs or the thatch?  We should keep this possibility in mind, shouldn't we?

You have not mentioned fertilizing, but you have not mentioned not fertilizing either.  People who are devoted to their lawn often fertilize it - right?  Would you say that you've done that?  If not, we can turn the page and discuss the next possible root of your thatch problem...

And if those delicate strands are Kentucky bluegrass, it means you have grass that is naturally inclined to thatch up.  Which just means you have to be a little more careful when you're growing Blugrass.  Perennial Rye and Tall Fescue have different growth habits and do not form thatch.  Healthy Bluegrass in healthy soil does not thatch up, either.  

You want a soil pH as close to perfect as possible - which as I mentioned yesterday is around 6.5.  That's because thatch rises as soil pH decreases, because as you lower the pH, and as the soil becomes more acid, biological activity in the soil begins to slow down - and thatch stops decomposing.  A nice Pelletized Lime treatment WILL certainly help.  Fungicides, pesticides, herbicides and now even Fertilizer WON'T help.

If you really want to get down to business, you could either core aerate or roughly till - remember, don't mix it too much, you're not making a cake and you don't want to upset the Earthworms - and topdress with something called TechnaGro, if you can find it, Earth Blend, Earthlife (from a Maine company called Coast of Maine (plug your zipcode into the website box to find that line in your area (www.coastofmaine.com/dealers.shtml)), Comtil compost ("CMS"). If those aren't available in your area, organic Manure, Humus, Compost, etc., will also literally put new life in your soil.

Whent he soil is finished, you can put down some more Kentucky Bluegrass.  This time, aim for a cultivar that does not tend to thatch up.  Although most people figure grass is grass, incredible sums of research dollars are spent inventing better grass.  You may as well get some of that.

The weeds that are annuals, you don't have to worry about.  Next spring, when the Forsythia is blooming and the whole countryside is yellow, you put down the Corn Gluten Meal and stop the weeds from germinating.  The new grass you sow this autumn will be ready to spring into action.

Let's take another look at your Grubs problem, since you brought it up.

The truth is, Milky Spore Disease does not work overnight.  It's slow, very slow.  But it works.

There are other ways to fight the battle of the grubs.  I've done several.  But my favorite is Milky Spore Disease, because it is so easy to do, relatively inexpensive, and long term.  And contrary to my posting yesterday, where I think I may have referred to it as a fungus, it is a grib-loving bacteria.  Never give advice while very tired without checking it twice.

There are several other ways to make grubs sick and die.  I've used them all.

Certain tiny, parasitic worms called Nematodes are sold for mixing with water and pouring on garden or lawn soil.  Some are better than others, but they are all good, and I always like to choose "all of the above" when possible because why wait?

There are also a few special kinds of flying insects that are called Wasps, but seem closer to Flies and do not sting.  These seek out grubs to lay their eggs; when the eggs hatch, the Wasp larvae eat the grub they're attached to.  End of grubs.

These are easy to purchase from Gardens Alive! (www.gardensalive.com), which is one of my supply standbys.  Their website explains the behavior of these predators in full.  You may even like their approach to de-thatching your lawn.

Your grubs problem may simply vanish once you get your thatch problem under control.  Grubs are not generally considered the cause of thatch.  So I think you should entertain that possibility.  

I know, I know, you're thinking, But the grass died as a result of the grubs!

It is possible of course that they did kill so many Bluegrasses - the grubs just saw your address as the Land Of Opportunity and staked a claim on your house - and thatch followed.  

Or it is possible the thatch appeared, after which the grubs saw your address as the Opportunity, the streets paved with gold, and moved in then.  

Whatever the truth may be, you can get rid of your thatch and your grubs.  Now's the time.  Strike while the iron's hot, to use a phrase from Meet The Parents.  And now that you have the weekend to work on it, you can order your grass on the internet (www.seedland.com), get a reservation on your aerator or tiller, order those amendments, the sky's the limit.

Next time, I will be sure to number the chapters.

Day is done.  Any more thoughts on any of the above?