Lawns - Brown spots/dallisgrass/broadleaf - best way to approach?

I've been hit with these problems at the same time. I've got dallisgrass appearing in some patches in the lawn, broadleaf in other areas, and some brown spots. I'm looking for any advice on the best way to attack all three without creating additional problems.

I'm located in Northern NJ, and the lawn is kentucky bluegrass.

I had started leaving the grass a little longer (about 3") just prior to these problems appearing. I thought I was doing some good, but after reading a number of articles saying that kentucky bluegrass should be cut to 1.5-2.5", I'm wondering if I caused more harm than good.

Can I address the dallisgrass and broadleaf at the same time, since they are in different areas. I plan on spraying each with the appropriate version of Ortho Weed B Gone.

The brown patches started off small, but have expanded a bit. They appear to be at the apex of where the lawn slopes are. Nothing extraordinary, but a slight peak in the lawn. Is this possibly due to insufficient water retention in these areas? They are getting watered, and the rest of the lawn is a nice dark green. Would SummerGuard help this? Could Summerguard be applied to the whole lawn while I spot treat for the other problems I've discussed?

I did a lot of work last fall to replace the lawn, by soil and seed, and was extremely happy with how it came in this year. I don't want to lose this!

Thanks in advance.

Hi Whales,

I'm not one to use the Ortho products so I can't give you much advice on those. I do have a calendar that might be helpful about applying herbicides for cool season grasses.
http://www.ext.vt.edu/pubs/turf/430-523/430-523.pdf

For the dallisgrass here's some helpful info.
http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn7491.html

You mention other broad leaf weeds. Though this site is based in California I find it has wonderful info, especially when considering environmentally friendly ways of dealing with problems.
http://www.ipm.ucdavis.edu/PMG/selectnewpest.landscape.html#WEED
http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn74113.html

As to the brown spots, it would be best to see if you can id the cause. Take a look here.
http://www.extension.umn.edu/projects/yardandgarden/diagnostics/mainturf.html

I have found this site very helpful when it comes to the needs of turf types. It says that Kentucky blue can be mowed as high as 2" to 2 1/2". Lots of other helpful info including the diseases it's prone to.
http://www.turf.uiuc.edu/turfSpecies/tourseason/CoolFrames.html

Here's some sites on organic lawn care that should be helpful.
http://www.organicgardening.com/feature/0,7518,s1-5-18-142,00.html
http://216.109.89.116/backyardwildlifehabitat/organiclawn.cfm

Newt