Couple things first jangell.
A. I can't get the thread you are referencing to work. GW says "opps!"

B. Spend a little time researching "poa annua" Studies have shown that it is mainly a winter annual that germinates in fall, once soil temps drop below 70 degrees. However, they are also finding strains that germinate in spring, again when soil temps rise into the 50's. So really, it is a two headed monster. There is a lot of info out there to be read, this is just an example - http://www.grounds-mag.com/mag/grounds_maintenance_taking_control/

To answer your questions:

>"1. Dimension - Can this be purchased in the western part of the US (NorthWet - Seattle to be exact) What brand name is it sold under? "

I believe so, why not? Look on the labels of the bags for the herbicide named Dithiopyr. Scotts does NOT use Dithiopr, although house brand names at Lowes and Home Depot do.

>"2. Granular vs liquid"

It is available either way.
Home owners will use granular because of cost.
Pros will buy liquid which comes in LARGE quantities. We're talking $700 for the smallest container.

>"3. Aerating - Before or after putting down dimensions"

(sigh) ...It is my belief that weed problems, such as a poa annua infestation are caused by core aerating. When you read my link above or research further, you will learn that poa annua seeds remain viable under the soils surface for YEARS. Aerating brings this hidden soil with the viable seeds to the surface - then they receive the moisture, warmth and sunlight to germinate. I believe in "let a sleeping dog lie" and not aerate ... not disturbing the soil at all.

So to answer your question - if you feel you really must aerate, then aerate first and then after irrigating the core plugs, apply the pre-emergent herbicide. Hopefully whatever junk you brought up to the surface will not germinate because of the herbicide ... maybe. I personally refuse to aerate because this risk out weighes the rewards.

>"I want to desperately control the spread of the POA and can use some help."

Do a split application then. Concentrate on poa annua's germination time frames. Apply early spring (disregarding crab grass germination time frame, ie drop earlier) and then again in late summer, just before it begins to cool down.

FWIW, out on the east coast last year, they had a VERY cool and wet June, and poa annua germinated then. For this reason some are planning three applications this year. It's all about the soil temps.

I hope this helps.
-Gary

Excellent Gary...Many thanks for your advice.

I will be getting on it this weekend!