On 6/13/2012 11:41 AM, Dr Mike Oxgreen wrote:
Frank;961561 Wrote:
On Wednesday, June 13, 2012 10:05:35 AM UTC-4,
wrote:-
On Jun 13, 8:19*am, Frank wrote:-
On 6/13/2012 1:21 AM, Dr Mike Oxgreen wrote:




-
'mike[_8_ Wrote:
;961511']I've had some small success mixing detergent with roundup
and using a brush to paint it on individual blades of offending
grass.
Hi mike...-
-
Thanks for replying!-
-
Unfortunately I've got large areas of grass that are dominated by
Yorkshire Fog; at a guess I'd say at least a quarter to a third of
the
lawn, in large patches. So it won't be practical for me to be so
selective with the glyphosate. I think my choice is between nuking
large
areas and reseeding, or finding a long-term cultural regime that
favours
the fine grass at the expense of the Fog.-
-
Something I didn't mention in my opening post was that I did
glyphosate
some of the very worst patches last year, where the Fog had formed
particularly dense tufts. I then reseeded with fine grass. So I now
have
patches of very fine grass mixed in with the patches of very coarse
grass, which admittedly looks a bit daft but at least it's a step in
the
right direction!-

There are some new herbicides available. *Google them up. *They may
just
hit the course grass and leave the good stuff alone.- Hide quoted text
-

- Show quoted text --

Being in the US, I don't know about Yorkshire Fog,
but undesirable grasses are a big problem and share
many of the same issues. The biggest one is that
for many of them, there is no selective herbicide.
I'd do what Frank suggested, ie google and see if
you can find one. The next issue is that many of
those are regulated, not sold to consumers, or if
they are they come in sizes and costs targeted for
commercial use.
The real problem here is that, well, it's a grass.
So, it's a lot harder to make a herbicide that will
kill the undesirable, but not the desirable grass.
If you can find one that will work and that you can
get, it's going to be your best solution.

The other unfortunate thing you're usually up against
is that the undesirable is a rough, tough grass, grows
fast, etc. Meaning in a war between it and the turf
grass, the undesirable is usually going to win.
Another factor is how that particular grass spreads.
If it's via rhizomes, even more trouble. In short,
I have not had much success in trying to deal with
it in any way other than killing it with herbicide.

In my experience, if there is a substantial infestation,
the best course is to kill it off and renovate. It's
not that hard. Essentially you kill it off with glyphosate
in very early Fall. Then when it's all dead, mow it
short, rake up debris. You could core aerate at this
point. Then rent an over-seeder, which is a gas
powered machine that cuts grooves in the soil and
drops the seed. Apply starter, keep it constantly
damp and in 2 months you'll have some decent
cover. It won't look real good though until Spring.

If you have just a few spots, you can do the kill
on just those, again, I'd do it in early Fall.-

I had googled out of curiousity and did get hits indicating such stuff
is available in the UK. Did not have the time to look at the details.
I've been in a situation with Japanese Stilt Grass here and going
through same type stuff. In this case, outside of Round-up the only
thing that works are pre-emergents. Older crabgrass killers with
arsenic would have worked but are now banned. There is a newer crab
grass killer that also takes out about 200 undesireable grasses and
weeds but a call to Ortho said not the stilt grass. This is another
potential avenue for our UK inquirer, is to call the big herbecide
producers and ask them about his problem.

A couple of weeks ago, I did find an online reference to a selective
herbicide that targets coarse grasses but leaves fine grasses intact.
It's called "Rescue", and is obviously intended for golf course
managers. It sounds very exciting, but unfortunately it costs about £350
(about $540) for a one litre bottle (about a quart) treating 10,000
square metres (about 2 and a half acres). I'm not sure if you can even
buy it unless you have a licence. It's very new, so I'm guessing the
manufacturer is at the "make as much money as possible before the patent
runs out" stage.

Let's hope that this product becomes available in a quantity and
strength that's more suitable for the home gardener. But for the moment,
it's a bit out of reach.

I think I will probably do as some of you are hinting: kill off larger
areas and reseed.

Depending on how the stuff propagates, you may need to kill it ALL.
I get a lot of weed influx from my neighbor. Only long-term solution
is to nuke her yard.

At least I have established some confidence at this,
because the small patches I reseeded last year are looking quite good.
If I do spray glyphosate a couple of weeks before I do my planned
renovation work in September (scarify, aerate, maybe top-dress and then
reseed) then the scarifier will do the job of removing the dead grass
for me.