Question
QUESTION: What is the best month to fertilizer the lawn with a pre-emergence weed fertilizer? I live in south Jersey.
      Thank you.

ANSWER: Pre-emergent Corn Gluten Meal is applied at the same time as traditional Chemical Weedkillers.  The concepts are the same, the results don't wipe out your Earthworms and Bird populations.

Pre-emergents attack new sprouting Weeds ONLY by interrupting the germination cycle.  The schedule varies by USDA Zone, but it can also vary on a very local level.  The Soil and air temps that trigger Weeds to sprout also launch the blooming of Forsythia, those Yellow bushes in yards across America.  As the first blooms open, the Pre-emergents go down.  If you wait, most Weeds will have gotten too established to be felled by any Pre-emergent.

Established Weeds -- any perennial Weed that was around last year (Dandelions, for instance) -- are not affected by Pre-Emergent Weedkillers.

Best thing is to be ready with the spreader and the Pre-Emergent so that you can get it down right on time.

Got that?

---------- FOLLOW-UP ----------

QUESTION: What month is the application? I heard late February or earl March. Is this true?
         Thank you.

Answer
You're right USUALLY -- late February/early March are mild enough in Southern NJ for Forsythia buds to break ... and annual Weeds to germinate.

But don't generalize when scheduling this work.  It's not like putting down Fertilizer.  Pre-emergents ONLY interrupt the germination cycle; they don't affect growth after that.  Erring on the EARLY side is better than using it too late; any pre-emergent will linger in the Soil long enough to zap a good number of Weed Seeds effectively.  To be safe, I'd shoot for Early February.

Now, if your Soil is healthy, it doesn't need Nitrogen.  Besides pushing blade growth over the top (leaving it vulnerable to Fungus attack), overdoing chemical N Fertilizer ALWAYS raises the Salt level of your Soil -- Bad for Grass and everything else down there (almost).  Besides, why pay for something when you don't need it?  If you are going to use a chemical Weed Killer, pick one with the smallest amount of N as you can find.

I always recommend Cornmeal Gluten products over the mass market Chemical Weed Killers, as you probably know, because they don't come with any ill side effects and break down into a slow release Nitrogen fertilizer all Summer long.

Thanks for your question.  I hope I was clearer this time!  Sorry - still recovering from the holidays. :)