said:

On Aug 21, 11:30 am, z wrote:
On Aug 21, 6:01 am, Eggs Zachtly wrote:





Richard Thoms said:

Quote: JL wrote on Thu, 16 August 2007 23:28
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I had a section of lawn that had crabgrass in years past.
This spring I used a product that contains Dimension (thanks ahlg).
It worked great. I have some stray crabgrass plants
that I deal with spot treatment.

Will I ruin my Dimension for next year if I de-thatch
this fall/next spring? That is, how long do I have to
wait for the crabgrass seeds to finally die before I'm
able to dethatch?
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I'm just curious. Why would de-thatching interfere with the pre-emergent?

The pre-emergent creates an invisible "barrier" that the weeds can't poke
through. Any distruption of that barrier renders it useless.

--

Eggs

Two can live as cheaply as one, for half as long.

Hmm. That's what about.com says as well.http://landscaping.about.com/od/weed...crab_grass.htm
I'm a little surprised; I don't know about the commercial stuff, but I
use corn gluten as a preemergent, which just inhibits root
development, so I never thought about whether "puncturing" it would be
a problem.- Hide quoted text -

- Show quoted text -

It's the same concept. Neither one forms a physical barrier that
crabgrass can't grow through. What they do is establish a top layer
of soil that crabgrass can't germinate in. If you disturb that layer
by dethatching, aerating, etc, you lose the protection.

The plants, themselves, also aid to the destruction of the barrier. Each
one pokes a miniscule hole in the barrier, then dies. After millions of
holes are poked, weeds start getting through. It's inevitable. Hopefully,
there's not enough time left in the growing season for those plants to
reach maturity. =)

--

Eggs

After heat killed bad germs, where do they go? Obviously not in heaven,
since they've been bad. Surely then can't go to hell, for the heat would
kill them again(?)...