Peter Pan wrote:

The stuff I put down from Scotts says "Turf Builder with Crabgass
Preventer".. Is this a pre-emergent or do I need to get away from Scotts
and get something else?

the product you mention contains a component that will prevent
the crabgrass seed in the soil from germinating. that particular
product will not kill crabgrass that has already germinated and
sprouted, nor will that product have any effect on the various
other types of undesirable broadleaf weed seed resident in your
soil. pre-emergents work by stopping the seed from germinating.
since crabgrass is a hot weather weed, usually the first frost
begins the process of killing the living growing crabgrass. next
years crabgrass crop is the result of the previous years crop
having left seed in the soil.

post emergent selective herbicides are required to kill undesirable
living growing broadleaf weeds. the general rule is not to apply
liquid post emergent selective herbicides after the ambient daily
temperatures have exceeded 80 degrees F and don't apply under drought
conditions.

I use Lesco products on my lawn and in my lawn care business.