It's mid-summer, and I'm wondering what to do at this point. Do I let it run its course and use what I've learned to prevent it next season. Or is that asking for trouble? If the suggestion is to use post-emergence crabgrass killer, should I do it right away or after the summer heat?

My lawn is about 15,000 sq ft. About a third of it is crab grass free. Another third of it is really bad (shown in the picture) and the last third looks okay but I see small specs of bright green crab grass starting to sprout.

Did you reseed at all this year?

How high/low are you mowing?

How often do you water and for how long?

I usually mow at 3". I had a problem with my irrigation until recently, so I've only run the sprinklers twice so far -- trying once per week, 1" of water.

What do you think you've learned about preventing crabgrass for next year? I'm curious to see what sinks in and what doesn't.

Your lawn needs a lot of work. What do you want it to look like? Do you want it to be the yard of the month or is 'just green' good enough? If you want it to be the yard of the month, get a professional soil test from Logan Labs. If just green is fine, you can skip the soil test.

There is a chemical post emergent for crabgrass. I'm an organic guy and don't know what it is. Look around for crabgrass and post emergent.

Your lawn is in poor shape. You can start fertilizing now with organic fertilizer. Organics is the fast track to success in the summer. Try this with chemicals and you'll have a dead lawn in a week or two. The fertilizer of choice for this year is alfalfa pellets. Cost and performance wise, this is the one. Apply the first time at 10 pounds per 1,000 square feet. That is sort of an announcement to your soil that you are going to be applying more. If you overdose at first, the soil will not be ready for it and you'll get a little stink going on. You don't want that for a couple reasons. So start slow. Then after a month goes by, you can apply more at 20 pounds per 1,000. And after another month you can apply at 30 pounds or more depending on your wallet. 20 pounds is generally plenty but some people get really excited when they see the results and want MORE!!! Once you awaken the microbes in the soil, you cannot over apply. When you apply alfalfa pellets (rabbit food), you should moisten them immediately. The reason is so the birds cannot come in and carry them away. Moistening them makes them swell and burst open. It doesn't take much water.

Over seed early in late summer or early fall. When the evening high temps start to fall, then it is time. If you don't have any Kentucky bluegrass in the lawn, that makes a good grass to fill in when you get weak spots in the fescue. KBG must have full sun, and it will go dormant in the winter cold. Other than that, it is a great turf grass.

Here is a picture of the effect of alfalfa pellets. This is a zoysia lawn fertilized in May 2011 with a few handfuls of alfalfa. The photo was taken in June. Note the improved density, color, and growing height. This is what we're looking for in your lawn.

Regarding what sinks in around here for next time around -- well, a tall thick lawn would solve a lot of my problems. I'll be sure to mow high, water deep and infrequent, and throw in some pre-emergence herbicide to help.

As for right now, I'm following your advice. I've applied some post-emergence herbicide for the crab grass, and the next step is to buy some alfalfa pellets.

Thanks so much for taking the time to help me!