Preemergent is not magical dust and will not eradicate all weeds, just prevents SEEDS from emerging. So if you have renegade roots that still live in soil, p/e won't stop that. Also, wind and birds are constantly dropping unwanted seeds so p/e and weeding is an ongoing fight. Also must be conservative with p/e and follow instructions faithfully as excessive application can be counterproductive to growing plants you want. From your pics the p/e would have never deterred the weeds you show so I don't think it really failed as the rest looks pretty clean. With respect to those particular weeds? I hand pull after a rainy day with long tap root is easier to pull.

bossy, good post. Thanks. I wasn't sure if these were weeds that pre-emergent would suppress or not. Besides hand pulling and chemicals, is there a deterrent for these sort of weeds so they never grow to begin with?

If I knew I'd sell it and be a $$$$$. I am from the school that manual removal is the most effective but that may not be practical due to garden size, physical ability, time. I have learned to live grudgingly with some lawn weeds but fight like hell against the weeds in garden beds. I also think we forget that most, if not all, of the good cultural practices are good for plants AND for weeds and the only hope is that desirable plants outgrow/choke out the weeds but that sometimes does not happen. Weeds and the fight against them is part of being a gardener

I'm in Greenville SC, so not too different of a climate zone. Fall of 2014, I had a similar situation as yours, but much worse. Sodded Bermuda with a massive number of broadleaf and grassy weeds (maybe about 3x what your pics show). Battled those down all of 2015 and did a lot of reading and research to figure out what my weeds were and what was the best way to make the next year better. I went with an application of Prodiamine, which is the same active ingredient in Stonewall. I had planned to do a split application, but decided the 2nd app wasn't needed because of our mild temperatures. So, it was about 0.2oz/1000 sqft applied Sept 12th 2015 with my sprayer. I went with the liquid for better coverage. This was my first time using it, and I am very impressed with the results. I have almost no broadleaf weeds so far this year *except* right around the edges of the lawn where I probably didn't spray well.

In your 2nd pic, I believe the weed on the right is a Carolina Geranium, and the middle one is some sort of thistle (Creeping Thistle?). Not sure about that left one, however, Prodiamine should have fairly consistently knocked out those first two. That makes me think either the application wasn't enough, wasn't timed correctly, or wasn't spread evenly. So, if I had to suggest a change for next year, you might try the liquid instead of the granules, and apply about a month earlier. Target Sept 15th for our area, but with Prodiamine, it lasts a good amount of time in the soil, so earlier won't be a bad thing.

Thanks Brandon. Another good post. I have used Stonewall or Dimension in granular form in the past and have had pretty good results. The only thing that changed this year/last fall is I did a split application. There is another broadleaf weed that will start to grow about a month or so from now. It has shallow purple roots and is very easy to pull. I have struggled controlling that in the past and was hoping the split application would knock that out.

Back to my problem this year, I didn't know if the weeds were perennials which would mean pre-emergents wouldn't touch them or if there was an application issue. I'm getting mixed responses from you and bossy but the only thing I can control is application. I will definitely look at the liquid form. My other problem is I am very conservative in my timing. I normally don't put down a pre-emergent in the fall until I am completely done giving my yard nitrogen. I looked at the log I keep and I put it down September 25 last year. Who knows when it rained but I normally don't put something down unless I know it will get watered in fairly soon. I will target labor day or earlier this year especially since I plan on using a split application. Thanks again for the input.

My preM didn't stop the plantain from coming into my Bermuda with abundance this year... I had to do a spot spray this weekend.