Crabgrass is an annual plant that dies when the cold weather hits. Right before that, it sends up the seeds. You don't say where you live or what your other grass is, so I'll guess and sort of lay it out. If you live in the south, there is a cure for crabgrass without killing St Augustine. If you don't have St Augustine, then you can wait it out and do what you are doing in the front next year. If you get some control over your watering, try to water only once a week during the heat of summer and more like once a month the rest of the year. That will keep most weeds out. Mowing at your mower's highest setting works to keep weeds out, too.

Hi, kimmsr, Thanks so much for replying. I got a soil test in 2012, but I've added some organic matter since then. The pH was 7.7; the organic matter was 3.2%. When I dig a hole to plant a tree and fill it with water, it drains at what I imagine to be an average rate. I can't remember exactly, but it didn't seem super fast or slow, I think a hour or two to empty. It holds water pretty normally too. If I water 1 to 1.5 hours one morning, the next day the very top of the soil looks bone dry, but just underneath or within a half inch there's plenty of moisture. There seems to be an earthworm under almost every weed I dig up. Once the lupines get going there are bees everywhere, and I see ladybugs, ground beetles, and little spiders every so often. The soil smells great, in my opinion. It's good-looking soil, nice and black when wet, with a good texture, not too crumbly or too sticky. A layer of reddish-brown clay becomes prominent about 10 to 12 inches down. I haven't noticed hardpan. In the soil test, nutrients were (in ppm): nitrate-N 8, phosphorus 45, potassium 167, magnesium 294, calcium 2099, sodium 25. Soluble salts 0.2 mmhos/cm. Per their recommendations, I added elemental sulfur to the vegetable garden, but I haven't amended the flower beds. By the way, there's an underground irrigation system, and I just paid a guy to come out and replace the heads along the fence with "shrub heads" 16 inches tall and move some of them closer to the fence. Thanks This post was edited by myrmayde on Thu, Jul 24, 14 at 14:30

It can be very difficult to hit a target amount of clover in the lawn. I wouldn't mind some, but it's not in the cards...the lawn chokes out any invaders. One thing you can do is feed properly. If synthetic, Memorial Day, Labor Day, and October first, then winterize when growth stops but the lawn's still green (probably early December in NC, but that's going to vary). The nitrogen hands the advantage to the grasses and, with overseeding, should slowly increase the grass' dominance. Organic feeding schedule differ a bit--May 1, August 1, September 1, (optional) October 1, and then winterize. Theoretically, for larger areas, wiping the deck with Round Up and reseeding the fescue with a measured amount of Dutch clover would work. That's also a LOT of work, very annoying, and means you have to restart sections of perfectly acceptable grass. Proper watering--which you're pretty close to--will also help hand the advantage to the lawn. Clover is more drought-tolerant than any lawn, so watering enough to keep the grass happy is critical. For existing grasses, mow long as well. 3" at minimum is best, both to shadow out any excess clover (and other weeds) and to make the grass a little less water demanding. If you do all that and still can't get any control over the situation, soil test with Logan Labs. It could very well be that there's a resource shortage (extremely common) that's limiting the health of the lawn.

Picture #1: If you think that dead spot is from a dog, scatter some table sugar on the area. I've never seen a spot that big from dogs, so I'm not sure what the rate would be. Excess sugar is harmless, so I'd probably put 'several' cups of sugar on that area. Moisten afterwards, but don't wash it away. Give that 3 weeks before you do anything else in that area. The grass might come right back. If it does, it will be greener and faster growing that the adjacent grass. Sugar is not a fertilizer, but it will stimulate the microbes in the soil to go into mass production of organic fertilizer. Picture #2: Yes that was clover and yes, the herbicide kicked in. Although I've never seen Dutch white clover that did not have a white shadow ring through the middle of the leaves...like this. In any case, it's going away soon. Picture #3: If you decide to reseed that area, I would do a full renovation. Oops! I just remembered something about RoundUp from your initial post. I guess you can't do what I was going to suggest. The renovation approach I like involves two rounds of Round Up, one week apart with lots of shallow watering during the process. If you don't like glyphosate then that's out. So instead, tell me about your watering schedule. How often and for how long do you water the lawn? I think I'm going to suggest a change to that and see what happens.