Those are true Dutch white clover. A lot of plants look like clover but that is the real thing. PULL THEM IMMEDIATELY, because clover seeds like crazy. Do NOT let the clover form the white flowers. St Aug is usually a dominant force in the lawn against grassy plants, but it is a little baby against broadleafed plants. Even really poor plants will shade out St Aug. Your best defense is to mow the St Aug at the mower's highest setting - always. Atrazine has a diminishing return when reused. I would not use it until at least mid spring. Wait for all the weeds to come back in full force and then blast them. And then don't use any more atrazine for a year. For now, it looks like your lawn is dormant. You might get away with spot-spraying some Weed-B-Gone Clover, Chickweed, and Oxalis. When St Aug is growing, the WBG will take it out, but when it's dormant, you might get away with it. To be more careful you could use cardboard as a shield so you only spray the clover.

With bermuda my unspoken idea won't work. Best left unspoken. RoundUp is a tough love approach. You have gotten the wrong idea about it from someone. RU kills the grass it gets on. It might take a few days for the grass to show that its dying but it is. Once it is dead, the surviving bermuda surrounding the weeds will be free to fill back in. Typically you can spray RU and the next week plant seed. But if your lawn is a sodded type of bermuda, then don't seed it. Is this hybrid (i.e. sodded) bermuda or common (seeded) bermuda?

St Augustine is different from other grasses when it comes to herbicide. On one hand it can handle lots of salt but it cannot handle the normal broadleaf herbicides tolerated by every other grass. So you cannot use normal Weed-B-Gone with it. The weed killer you need has atrazine in it. You can only use atrazine products one time per year, so be sure you're doing it right. Spectracide's weed product for St Aug looks like this... This particular bottle is easy to use. All you do is connect the hose and go. About a week before you spray, water the lawn heavily. Apply about an inch of water on Saturday and spray the herbicide on the next Saturday. Weeds dies best when they are fairly healthy. When you spray, stretch the hose all the way out to the farthest reach you want to spray and work your way, backwards, away from where you've sprayed. DO NOT walk through this stuff or let the pets on it. Atrazine is nasty stuff. All you have to do is mist the leaves, not drench the soil. And you might not see results immediately...or even in a week, but in 3 weeks, all of a sudden, you'll notice no more weeds. Now that I think about it, I would leave your current weeds the way they are and wait until spring to spray this stuff. Since it says to only spray once a year, why not spray to kill out all the summer weeds? I'm thinking late April would be good in most of LA. That will give the St Aug the rest of spring to refill where the weeds were and all summer to enjoy. As for fertilizer, I'm an organic guy. I haven't used a chemical fertilizer in 11 years. If you want a recommendation about organics, then apply alfalfa pellets (rabbit chow) at a rate of 10 pounds per 1,000 square feet now. In 3 weeks, apply again at 20 pounds per 1,000 square feet. That will take care of your fertilizer for the winter. If you are not mowing at your mower's highest setting, start that now. St Aug will always be weedy when mowed too low. And if you are watering more frequently than once per month this time of year, you should wean your grass from the frequent watering to watering much less often. When you do water, apply 1 inch as measured by tuna or cat food cans.

[set soapbox mode on] Okay now I'm taking it personally. You can check all the sources you want, but I can assure you it becomes baffling almost immediately, especially if you spend much time reading peer reviewed university journal articles. What we have here in this and other forums is hundreds if not thousands of peers reviewing what we do and reviewing it in much less baffling terms. The text that I copy and paste is my own, so I don't need to site sources. When I came to this forum I was doing almost everything wrong. I was convinced I was fairly correct because I attended a land grant university and took classes covering this stuff. After a few heated forum battles I tried some of the things these illiterates were writing. Lo and behold they worked for me. After that I looked back at other suggestions my "opponents" were making. Some seemed counterintuitive, so I looked into the science soil biology. From that and what I had learned of human physiology in grad school, I created the Organic Lawn Care FAQ, available on the GW Organic Gardening FAQ section. I posted that FAQ on several sites. Those sites with download counters registered well over 75,000 downloads each. Nobody in the forums seemed to be arguing against my work, so I guess you could call that peer reviewed. My lawn owner peers - perhaps not your ivory tower peers. As a result of that document I was asked to moderate three new organic lawn care forums at other e-locations. Again I am calling this a reasonable review of the concepts I set forth. I consider the Organic Lawn Care FAQ the first easy to read concept document on organics since J.I Rodale popularized it in the 1950s. His compost approach was nice until we got the technology to study DNA in the soil. With testing done in the 90s and 2000s we learned that compost wasn't a be-all, end-all magic bullet. Compost is little more than a collection of microbes and microbe carcasses. It works great as a mulch. But the benefit to organics comes from feeding real food to the soil microbes. Then you'll have to read Dr. Elaine Ingham's Soil Biology Primer to learn how that food gets processed into plant food. While that document is not trivial reading, it is readable to us unwashed. What I try to provide is best practices for low hassle lawn care. These practices have been reviewed in other lawn forums and tuned up over the years. Yes there are ways to make it harder and more expensive, but I don't want to work that hard myself. I even copy and paste some of the things I have written, because that has a lower hassle factor than recreating it again and again. Every now and then something new happens in home owner lawn care. Two examples that come to mind are leveling and sprigging. Several years ago Dave Proud brought us an illustrated and detailed account of how he leveled his bermuda grass lawn. Before that we never discussed leveling to get rid of a bumpy surface. It was an epiphany. The lights went on and we dug into that. I got him to join another forum for lawn nuts, and the process has been used a lot. That general topic fed into the question of why lawns get bumpy. Rototilling was discussed among homeowners and professionals. Rototilling seems to be the root cause, or at least one root cause. Another fairly recent homeowner discovers is sprigging a few dollars worth of very expensive bermuda stolons onto bare soil. This process came to us from R. Simon in Australia. It seems like he developed the process and made it work. On this topic I do not know if anyone else has sprigged successfully. I spend more time in this forum where there are more beginners than I do in the other forum, so they could be sprigging all the time over there. My point is that if and when someone has a better idea about lawn care, I'm going to bring it to the forums and discuss it. Generally those ideas do not come from peer reviewed journals out of the universities. But if, for example, you want peer reviewed evidence that shampoo will soften your soil, search the journals for "Cascade Plus, golf course, core aeration." Without the quotes of course. You'll find plenty of articles on the use of a concentrated surfactant called Cascade Plus being used to replace core aeration on golf courses. Shampoo is also a concentrated surfactant. I did not invent the use of shampoo, but when I tried it, and it worked like magic for me, I was all over it. Please go ahead and look at all the sources you want. Come back with your ideas and we can talk about them. I have reasons for not top dressing, not core aerating, not rototilling, and all the other oddball stuff I suggest. You don't have to believe them or agree. You are free to present your thoughts, but what irks me is when people refuse to spend $0.50 on shampoo but they will spend $75 to rent a back breaking machine that will not work nearly as well. ...all because they read a peer reviewed journal about core aerating. [set soapbox off]