"Pam" wrote in message
...
Preen works exactly as it is intended to - it is a premergent herbicide
that will prevent seeds (any, not just weeds) from fully germinating. It
has no effect on existing weeds, which must be removed prior to
application. The effects can last upto 4-6 months. I would avoid combo
products - they tend to be counterproductive and often the timing is off
for one of the applications.

pam - gardengal

Wouldn't plain old crabgrass preventer have the same effect? And a bag of
this is a lot cheaper than a box of Preen.

-al sung
Rapid Realm Technology, Inc.
Hopkinton, MA (Zone 6a)