Question
QUESTION: Hi,

We live in Southern New Hampshire and have been trying to turn our plot Organic for about 1.5 years, ever since we moved into our property.  The previous owner was, unfortunately, not like minded and used chemicals and synthetic fertilizer -- most likely at excecive rates.
I've been very pleased with the lawn (about 15,000 Sq/Feet), except for one area.  About 5 weeks ago, an area of about 500 Sq/Feet just turned brown.  We have had a drought in the area this summer and its been extremely hot, and the area is generally exposed to sun all day long.  I thought the area just stopped for the season due to the conditions.  Yesterday we discovered that the sod just came off in huge lumps in this area (if I were to take a rake to the area, the sod would easily fall away, revealing dirt -- and grubs).  Looking closer we discovered a lot of grubs...in the order of 5-10 per sq foot.
So, obviously I don't want to put down chemicals (particularly imidacloprid, which is prevalent in most grub control products...which I understand has been linked to the killing off of bee populations).  

I've done some research on the internet and discovered a product, 'Milky Spore', that claims to be organic/natural.  I don't dispute that (but let me know if I'm not correct).

So...that was background...now to my question....sorry for the length in getting here.

So I have this 500 Sq/Feet of sod (very thick and dry to the bone).  I have this Milky Spore product.  It is just about October (late in the season).  What now?  Do I apply the product and re-seed?  If I do re-seed...should I remove the sod completely and sow the new seed in?  Should I just treat the area, leave the sod until spring and re-seed then?

ANSWER: Milky Spore is a terrific product, but it is not the magic bullet for your Grubs problem.  It is a great first step.  It has been very effective on my Lawn (it is very exciting to dig up a lawn patch and see a Grub with the milky white appearance that indicates it is infected with this bacteria).  But it takes time.  And it does not attack all Grubs.

5 to 10 Grubs per sq ft is generally considered the break point for a drought-damaged Lawn.  But my guess is that your Grass has suffered badly from the effects of drought and heat.  That alone will wipe out a Lawn.  Grubs being present is not a disaster.  Grubkiller companies like to make us feel like it is, but the numbers you are pointing to are very manageable.

You may find this page on Grubs by the Beyond Pesticides group informative:

http://www.beyondpesticides.org/infoservices/pesticidefactsheets/leasttoxic/micr

These are the current non-chemical methods of controlling a Grub problem.  Which, I should add, seems to surface almost always in a plot of land that was disturbed by new construction, tilling, etc.  It takes time to rebuild natural defenses in the Soil against these Grass predators.

I appreciate, and I really wish I could say it better, but it is so heartening to hear someone else talk about ways to put the birds and the bees first.  That imidacloprid is doing an awful lot of damage, and almost no one seems to want to acknowledge that.  They don't know, and they don't care.  So I think this will be my last question for the night, just so that I can go to bed thinking about this very nice question you asked and your concerns about our planet and our bees.

Milky Spore Disease is an easy, cheap, highly effective way of zapping these little beasties.  The spores live in the soil waiting for the gray larvae, then when one comes along the spores attack and the larvae dies.  No fuss, no muss.  

The trouble with Milky Spore is that it takes a year or two to get settled in your soil.  Next spring, contact Gardens Alive for beneficial nematodes, a parasite that also targets the Grubs:

www.gardensalive.com

I understand Racoons and Skunks like to make meals out of these insects.  They tear up your turf in the process of searching out dinner.  Organic, but unsightly.  Probably very prevalent in Southern NH.

Please look over your non-chemical choices and let me know your thoughts.  Thanks for writing.

---------- FOLLOW-UP ----------

QUESTION: Thanks for your response on Milky Spore and links to other organic means of controlling them.  I did however have a more critical question that was not answered.  What do I do now with the patch?  Please see last paragraph on my original post.

Thanks in advance.

Answer
I tend to be overoptimistic, so if this was my yard, I would apply half of the container of Milky Spore powder -- Bacillus popilliae -- liberally, then roll up and turn over the damaged turf and re-seed right away.  In the Spring, I would re-apply.  The weather may still be mild enough for your newly seeded Grass to become established in time for winter, although Kentucky Bluegrass may not be so lucky because it takes forever to grow at this time of year.  The powder can be used as long as the ground is not frozen.  Grubs will be heading deeper at this point.  When they surface next Spring, the B.p. will be waiting for them.

However, you should prepare to leave some other surprises for resident Grubs next Spring.

Bacillus thuringiensis ('B.t.') should be one of them.  This is a Bacteria commonly found in Soil that attacks a lot of different insect larvae and caterpillars: Gypsy Moths, Mosquitoes, Black Flies and others.  You can buy containers of it to use on your Lawn.

Nematodes are another very good surprise.  These are tiny parasitic worms that are said to be the second most common animal, behind arthropods.  There are more than 20,000 species of them, bad and good.  You want the ones that hunt down insects, invade larvae and inject a fatal bacteria.  The trouble with Nematodes is that they are incredibly delicate.  If you place an order next Spring, be sure to follow the directions exactly.  And NEVER let the Soil become dessicated; this will surely wipe out your Nematodes population, along with weakening your Grass and asking for more trouble from Grubs.

Use caution even when applying natural IPM techniques.  Make sure you are well versed in the product.  For example, a parasitic Fungus called Beauveria attacks a lot of insect pests; but it also attacks Fish and Honey Bees, so it should be avoided completely.

I could go on, but why don't you see if I have missed something and let me know if you have any questions.  Thanks for writing.