I'm wanting to kill some clover and other stuff in my st augustinegrass. It's still brown / dormant I'm assuming. Can I spray roundup on it without hurting the grass?

NO!

I was looking to kill some of it today. There used to be a weed and feed fertilizer that you spread with dew still heavy, and the theory was that it would dry on the leaves of the clover and broad weeds, and it would kill it. No need to water it in.

I got up this AM looking for it at Lowe's and they don't have it anymore. I used to spread this stuff just for this reason this time of year.

Do NOT broadcast or spray round up even if the St.Augustine is dormant. The grass may be dormant, but the Roundup will still find its way to the roots.

I have the same problem this year. I put out winterizer, but the neighbor doesn't do anything, so his yard has spread to mine.

It is safe to weed and feed when the grass is still dormant?

Option #2:

Roundup your neighbor's lawn?

Weed and feed is a BAD idea, especially right now. You would only be "feeding" the weeds due to the grass being dormant, and probably putting way too much herbacide down.
http://www.ci.austin.tx.us/growgreen/weedandfeed.htm

Spot treat selectively with a broadleaf herbacide. You can also use 10% vinegar on sunny days, and it's still legal to pull them by hand.
http://aggie-horticulture.tamu.edu/plantanswers/turf/publications/weed2.html

No, St. Augustine never goes truly dormant. If you had a Bermuda lawn, then you could spray anything you wanted as long it it was dormant, but NOT on a St. Augustine lawn.

you can.....but only if you want to kill the entire lawn.


your choice

use 2-4d to kill broadleafs in St. Augustine

You can usually get 2-4d products at Lowes or Home depot in a hose in sprayer bottle. Works great on clover and other broadleaf weeds.