On Nov 30, 6:27*pm, Gordon wrote:
Some background:
So I bought this house two summers ago. When I moved in it
had been empty for over 6 months. *The lawn was a mess.
There were weeds growing that were taller than my 7 year
old son. My wife and I spent the better part of 3 days
just pulling weeds. *When the lawn came into it's own,
there was a lot of dirt. The back part of the lawn behind
the house was used as a dog run and was covered with wood
chips and pine needles. *A huge (and ongoing) effort is
going into raking and disposing of pine needles and wood
chips. I've managed to regain about 2/3rds of my back yard.

I have been trying to encourage the lawn to establish and
spread naturally.

Lawns don't spread and establish naturally, unless you let
them go to seed. Clump type grasses, eg tall fescue, is
one plant. The plant can grow larger if it has empty space
next to it, but it isn't going to grow from a 6" plant to fill your
back lawn. Bluegrass can spread via rhizomes but it would
take forever to fill a backyard that is bare.

I'd also consider what exactly you have there. You know you
can't make a silk pursue out of a sow's ear, right? If it's some
crap grass, poor texture, poor color, poor wear tolerance, etc,
would you want it to be your lawn?



I don't want to tear it up and re-sod.

Why? If cost is an issue, you could re-seed inexpensively.
Better and cheaper to do it right once, instead of screwing
around. Depending on the soil condition, it could be as simple
as killing it off with Roundup, core aerating, then using an
over-seeder to put down the new seed.


So I have been happy to see any grass growing. *But now I
see that I have crab grass in my developing lawn. ARrrggg!
A bunch of it was next to a part that I had re-seeded
this summer and the crab grass was invading the new grass.
So I spant an hour yesterday with a cultivator hoe digging
into the crab grass patch and pulling it up along with
it's long stringy roots.

You sure it's crabgrass? Crabgrass grows in the heat of summer
and dies off in early Fall. In Portland you have temps in the 30s at
night no? I'm in Coastal NJ where it's barely gotten down to
freezing and all the crabgrass has been dead since mid Oct.



Several of those roots ran into
the patch of new grass and came up with sveral tufts of
crab grass attached. I don't mind tearing up this patch
of crab grass since there appears to be no good grass in
here. *But I also see that there are patches of mixed
good/crab grass around the lawn.

Seems you're hell bent on doing everything the hard way.
Let's say you have a 6000 sq ft lawn.
In late Aug/early Sept I would have:

Sprayed the crap that is there with Roundup. 1 hour
Wait about 10 days until it;s all dead, mow short 1 hour
Rake up the major part of the debris 3 hours
Rent a core aerator 3 hours
Rent an overseeder 3 hours

Cost: $250

With an appropriate, quality grass seed, you'd be looking
at a half way decent lawn now and a mighty fine one by
summer.



What I wonder is: Should I try to uproot the crab grass
in these mixed patches? Or would it be better to just
sprey it down with crab crass killer?

It's been in the low 40s, or 30s at night for how long by you?
Crabgrass?


Also; It is probably too late in the season to think about
reseeding the bare patch where I uprooted the crab grass.
Would it be a good idea to mulch the patch with leaves for
the winter to keep the weeds out?

You're learning the big problem with pulling weeds. It
opens up the soil and allows a spot for more weeds to get
established. Forget about doing anything at this point.
Except maybe testing the soil and liming if necessary,

Depending on what you have there now and if you can
tolerate it another season, I'd either get through another
year and re-seed in the fall, or else re-seed in spring.
Fall is by far the best time. But then you're in OR with
plenty of rain and more moderate summer, right?
Main problem with spring seeding for you will be
competition from weeds. But if you keep after it, it
can be done.

As Frank suggested, the best solution with crabgrass
is to put down a pre-emergent in Spring. It's usually
sold together with fertilizer. BUT, if you do seeding in
the spring, make sure you use one of the pre-emergent
products, eg Tupersan, that is suitable for seeding, new
grass, etc. The conventional, most common ones
can't be used with new seeding. Another reason why
seeding in fall is better.




Locational info: I live in Portland, OR and we are going into
a dry cool spell. *Looks like no rain in the forecast for
the next few days.