Jimmy, the grass didn't "poke through the fabric;" dirt has settled in the
cracks (on top of the fabric) and seeds have taken root. Two of the
reasons why the grass has not grown from under the fabric: no sun to
encourage germination, not able to grow through the fabric (providing you
didn't damage the fabric when laying the bricks).

The "young ones" are different seeds that were ready to start when you
sprayed; Roundup does not affect anything that has not sprouted; it acts
on the foliage.

Cement would have helped quite a bit but not eliminated the issue since
cracks soon start happening and soon the weeds are there to greet you.

This is a time to use your tea kettle. Pour boiling water wherever you
see the grass appear.

Another solution is vinegar.

There are other things also but are either toxic and/or harmful to the
soil; some would have worked if applied prior to the fabric and only for a
year.

The big thing people miss when using landscape fabric, bark dust, etc., is
that the current vegetation might be addressed but there is dust/dirt that
accumulates on top and settles down for a place for seeds to take root.
Weeds are successful because they can grow in minimally "desirable"
conditions. Surely, you have seen something growing in a crack on the
side of a building and definitely in the cracks of sidewalks.

If all trace of dirt/dust/soil could be kept out, those common weed seeds
would have no place to take root. That is qualified with "common" because
there are plants which need no dirt.

Of course, you could let them grow to tall enough to pull them, water the
bricks to loosen the soil and pull the weeds by the roots - a solution for
someone with more time on their hands than most of us have and certainly
as exciting as watching snails race.

Keep pouring the boiling water which will be more effective than the
sprays; it will cook the about-to-sprout plants as well as those sprouted
and perhaps cook the seeds as well. Unfortunately, the problem will be
ongoing as dirt will collect and seeds will be scattered. We welcome it
with our lawns and hate it with our sidewalks and drives; contrary lot are
we humans.

Good luck. I feel badly for you, all that work and now the weeds; it
stinks!

Glenna


writes:
I am really struggle how to "permanently" eliminate
this type of weed on my brick patio.
Using the weed killer called ROUNDUP
does not really work --- it only makes some of
the leaves turned yellow, and then the young ones come back in a day or
so.

What is interesting is that I actually put some landscape fabric on
before we laid the bricks. It sounds like the grass pokes thru the fabric
!

Please see the image on the link below:

http://tinypic.com/537zqsm.jpg

http://tinypic.com/6767nl1.jpg


Does anybody in this forum know a better way to solve
the problem?

Thanks in advance


JIMMY