On Sun, 13 Nov 2011 18:39:16 -0600, zimpzampzormp wrote:

I am in the northern midwest, zone 5 and don't have a lot of experience
with Zoysia, but I am a professional LCO and have only a couple of lawns
with partial Zoysia. I find it goes dormant in late Sept, does survive
drought better than ryes and blue grasses. Occasionally Nutsedge does
pop up in the Zoysia and does seem to thrive. It grows the blade much
faster than the Zoysia and reproduces through "nuts" under the turf. I
don't know if it would completely overtake the Zoysia but do know that
in my zone the Zoysia will not overtake the Nutsedge. The best thing I
have found to control Nutsedge is Sledge Hammer by Gowan and can be
purchased in a homeowner formula. It will need a spreader sticker and
will need several applications to do the job. I have found that in mild
infestations that if you pull it by the root, before June, that it can
be eradicated because it hasn't had the chance to develop the "nut" yet.

Thanks for your great information about the interaction between zoysia
and nutsedge. It was very interesting.

I'm staying organic, so the Sledgehammer is out of the question in my
yard, and I've been doing the pull-thing. I've pulled tons of purple
nutsedge blades so very few are visible now, but I expect to be pulling
more blades as they regrow in coming months. Hopefully the winter will
slow the sedge down. Right now things are looking aesthetically
pleasing in the yard with the sedge not visible.

Yellow nutsedge seems to be a lot easier to eradicate by pulling than
purple nutsedge.