Advice Needed

I have about 5000 sq ft of backyard on the CT shoreline (zone 6) used by 2 small dogs for potty and play. The house was built c. 1840. The back of my yard slopes down to a small Inland Wetlands area (not my property but still my responsibility) and was filled many years ago with rough fill  i. e. rock and poor soil. 

I haven't used any chemicals on the yard for the 12 years I've been here and the lawn keeps looking worse and worse.  The grass is sparse in spots, there are lots of dandelions and an infestation of their cousin the catsear. I tried  covering the latter to kill them and later learned that they like the dark and that they spread by rhizomes.  I pulled them by hand the past 2 years and reseeded those areas but the grubs are working against that.  In the past I've tried beneficial nematodes and also Milky Spore but the grubs are still there. The good news is there are lots of earthworms there, too.

I don't mind some dandelions in the lawn but want a thicker, healthier turf.  I don't leave the clippings when I mow because I think I'm sowing more weed seeds. I don't water the lawn but rely on what Mother Nature provides.

Here's what I'm currently planning to try this spring:

Iron-X (from Gardens Alive) to spot kill as many of the existing dandelions and catsears as I can.

Lime to adjust pH to a  non-friendly to dandelions level

Bioinsecticide (from Gardens Alive) to attack the grubs.

Two more things I've been considering are:

1. the Organica All Natural Lawn Care Program or

2. applying Corn Gluten now (either WOW Supreme  from Gardens Alive or Luscious Lawns from Bradfield Organics) to fertilize and hopefully suppress new dandelion/catsear seedlings from germinating.

Any advice about which is the better way to go?  Should I do corn gluten this year and then try the Organica 4 step program next year?

Thanks in advance for reading all this and for your help.

Before I post my answer, keep in mind that I'm from the Pacific Northwest, a Zone 6 environment also, but in many ways much different then your environment. 

Ok, that didn't work, so here's my real reply.

what I'm trying to say is that it sounds like your lawn is trying to revert back to what was there before people came along.  Mainly, a seashore meadow. 
No chemicals for 12 years is good, but remember that all the stuff you mentioned are just materials you are artificialy introducing into a natural seashore meadow. 

I'd just set my mower to at least 3", better still, 4", let the clippings lay and when my neighbors comment on the untidyness of mylawn, tell them it's a natural seashore meadow.

Oh, and the milky spore and nematodes are very temperature dependant, timing is everything with these kinds of controls.  The temps have to be right and the bugs have to be active for these to work.  It can be a very small window of opportunity.

Thanks, Hank.  Especially for the info about the temp dependent nature of the milky spore and nematodes.  I never knew that

My advice:

MOW HIGH and leave the clippings!

You don't need to buy all that stuff.  Maybe buy a little fertilizer and have your pH tested and then, maybe, buy something to correct pH junk. 

By taking away the grass clippings year after year, you took away the organic matter and the fertility.  So your soil slowly turned into a cement like dirt.

Fix that and everything else will fix itself.