JS said:

I have a major problem controlling this trouble weed on my backyard.
I have sprayed the whole area with the liquid weed control I bought at
my local Home Depot two times but it did not appear to work.
Perhaps,
I did not use the right one.

Could some body help me indentify the type of weed and hopefully
advise me what kind of weed control I should use.

Thanks in advance,

Here are link to the images I took:

http://i284.photobucket.com/albums/l...vong/weed1.jpg

http://i284.photobucket.com/albums/l...vong/weed2.jpg

http://i284.photobucket.com/albums/l...vong/weed3.jpg

I'm not convinced you have crabgrass (an annual grassy weed).
You have one or more types of coarse, grassy weeds growing in your
yard. Stong possibility: quack grass (especially pic #2). Other
coarse perennial grasses that might fit your pictures include
orchard grass and various non-lawn type fescue and rye grasses.
(I'm basing this on problem grasses in northern areas like mine,
as you don't appear to say where you are located.)

Since these grasses grow taller than the your more desirable lawn, it
should be possible to spot treat them with glyphosate by applied with
some sort of sponge or wick (so only the weedy grass contacts the
herbicide). Use extreme caution, as this will any other plants it comes
in contact with, including your desirable lawn.

They next thing to do would be to pump up your lawn by mowing
it taller (and being sure to use a sharp blade!), core aeration followed
by an application of a slow release fertizer and proper watering for
your soil conditions. (Sandy soils need more frequent, but shorter
duration waterings than clay soils.)


--
Pat in Plymouth MI ('someplace.net' is comcast)

After enlightenment, the laundry.