Preemergence Herbicides

wdrake – posted 15 August 2001 05:41

I would like to understand how preemergence herbicides work. I realize that timing is critical and applications have to be made immediately prior to weed seed germination; however, it isn’t clear whether the herbicides “kill” the seeds, keep them from germinating, or prevent them from taking root. If seeds are not “killed” will they remain dormant until next year and then germinate? If the mechanism of control focuses on altering root growth, will the herbicide also damage turf with a root disease? My objective is to (begin) controlling crabgrass and goosegrass in (BitterBlue) St Augustinegrass that is ailing with of Take All Root Rot

Bill DrakeNiceville FL

tdkx – posted 19 August 2001 09:17

Pre-emergents work by destroying the radicle of a seed in the process of germination. Pre-emergents will have no effect on established plants. To control crabgrass in warm season areas you must apply a pre-emergent at least once a month. I’m not certain of your St. Ausustine grass’s reproductive mode. Make sure it is a perennial. If it is, then feel free to apply pre-emergents on a regular basis. Gallery is the best pre-emergent on the market right now(expensive) Balan and Barricade are two very good pre-emergents as well.

TDKX