Question
QUESTION: I live in Columbia, SC and have a St Augustine lawn.  Many weed products for southern lawns are for St Augustine turf, but say do not use on Floratam.  How can I identify the variety that I have?  A second question I have is that in the spring my lawn seems to get infiltrated with Poa/Poannua grass.  Any suggestions on how to prevent it?

ANSWER: There's no real way for a non-professional to tell Floratam from other St. Augustine varieties. I couldn't do it myself. It would really take a botanist in a laboratory to figure it out. My suggestion is to pick a few random patches in the yard, and treat them with the product in question. Then wait to see what happens. If the grass survives fine, you should be in good shape! If not. Well, now you know.

Poa Annua can be wiped out if you wait for the season to get really hot and dry, then do NOT water at all for about 10 days. Let the lawn get all crispy. Then turn on the water again and soak it for a few days. The Poa will not survive the hot drought, while the St. Augustine should bounce back just fine.

Good luck!

-C.J. Brown
www.TheLawnCoach.com

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

QUESTION: Thanks for the advice on the Floratam.  I know the Poa dies back during the summer, but is there a way to prevent it from coming back in the spring?  It seems like it would have already dropped seeds by the time the hot weather gets here.

Answer
You could try using preemergent herbicides in the fall before the new annual bluegrass infiltrates. I only caution you to understand that there is already a huge abundance of seed in the soil, and breaking the chain of events won't prevent any future outbreaks. It's a common misconception that stopping a seed producing weed like this will prevent future growth by stopping seed production. Unfortunately, the seed's there, and it'll keep trying to grow in.

Still, a well times application in the fall could give you some relief for that season.

-Good luck!