Question
This spring my son thought he'd help out by fertilizing the lawn while I was away (it was a nice thought which I did appreciate!) but unfortunatly, set the spreader so the fertilizer came out and covered the lawn like snow. The grass turned brown and was almost completely dead. I threw out some grass seed on it and it took, but now most of the lawn is INFESTED with either crab or quack grass (I can't tell which). Did the ph level change cause this? And how on earth do I get rid of it?! Please help! Our lawn was beautiful and now looks just awful.

Answer
Hi Jackie;
What the fertilizer did was it killed all the beneficial microbes that enrich the soil.
It just wore out all the nutrition in the soil.
Fertlizers don't enrich the soil, they feed the vegetation that grows there,including the weeds.
I am going to copy off the answer I just wrote to a questioner about using organics.
I have not used anything on my lawn for 8 years except sugar.
The nice thing about organics, besides the fact that all the products are non toxic.
Her problem was a brown patch, but as i was answering that, I got into my organic program, and suggested a website for her to check out. It would apply pretty much to your problem too.
chemicals don't STOP problems, they CAUSE more than they correct.
Hers is the text.

The watering every morning is probably the culprit.
Too much watering causes fungus, and it sounds like you have brown patch, a fungus.
Shallow watering causes the roots to come close to the surface to get water, and that exposes them to heat, cold and drought damage.
Watering deeply, to a depth of at least 6 inches, encourages roots to go deep, and that gives them protection from these damages.
I water deeply, and only have to water once a week, even in our hot Texas summers.
Your neighbor probably waters with soaker hoses, so you don't see water spraying, and don't know they are watering.
Watering with sprinklers wates water.
When the temperature gets up to 90, the water can evaporate 20 to 40 percent, accordimng thew the climate you have, the humidity, winds etc.
When it gets up to 98 tp 100+, it can evaporate 50 percent or more.
You pay for all that water resgistering on your meter, but your lawn isn't benefiting from it.
for the fungus.
I use 1/4th cup baking soda disolved in 1 gallon of water.
Maybe 2 gallons would work.
I can't find exactly how much baking soda you are supposed to use, so I have just used 1/4th cup,per gallon of water, and it worked, so I stayed with that.
Be sure to saturate the ground and grass well.
Rake off the dead grass in a few days, and I recommend going on a totally organic program.
With organics, there is no need for chimicals at all.
Baking soda for fungus, moss etc, sugar for feeding the beneficial microbes that enrich the soil, and watering deeply.
There are other things you can do to enhance the results you get. There are a lot of organic fertilizers, available, and alfalfa meal, corn gluten.
these things have been researched thoroughly, and probven to work well.
As long as i used chemicals, my lawn was mediocre, and I worked myself to death, and spent a small fortune.
Since I have been on the organic program, I have a much better, weedfree lawn, and work about an average of 2 to 3 hours per week. That includes planting new plants, pruning my roses and shrubs etc.
All I do for the grass is, put down 1 pound sugar per 250.sq.ft. of lawn, and water to a depth of t least 6 inches once a week.
My husband mows and edges.
That is all we do.
I am amazed at what the organic program has done for my lawn and garden.
The beneficial microbes enrich the soil, and weeds cann't thrive in rich soil. they like poor soil.
any weeds that do come up in my yard, don't live long enough for me to see them.
It took about 3 or 4 years for it to become weedfree.
I put down the sugar. In a couple weeks there were about half as many weeds. Each week, there were less of them. By early summer they didn;t sho at all.
The next spring some came up, but started disappearing right away, each year fewer came up, until about the 4th year, none even showed. My lawn has been weedfree ever since.
Yellow cornmeal even works on fungii.
I has some tiny green moss on the surface of an indoor plant, sprinkled some yellow cornmeal on it, watered it, and it did do away with the moss.
Howard Garret recommends an agricultural cornmeal, but so far, I have not been able to find any of that.
I joined Howard Garrett's ground crew.
That means I paid my yearly dues of about 25 dollars and I get full access to his site. the videos and all the furums.
There is more than a ton of information on that site, and it is updated all the time.
The web address is    www.dirtdoctor.com
Howard Garrett is a scientists ad well as having a degree in agriculture and some others.
What he doesn't know about organics isn't worth knowing.
You can go to the site and read about his test laboratory, and the things he has done nationwide.
Then decide if you want to join the site to learn more.
Charlotte

 Hope this helps you too, Phyllis.
Feel free to write any time you have questions you feel I can help with, or if you need clarification for any of these statements.
Charlotte