On 5/31/2010 12:56 PM, Eggs Zachtly wrote:
Kate said:

On 5/31/2010 8:13 AM, Eggs Zachtly wrote:
Kate said:

Does anyone know what to use to kill Johnson Grass (a noxious weed)
in my lawn?


There's nothing I know of that you can purchase (as a homeowner), that you can
spray on Johnson Grass (Sorghum halepense) in established turf, that will kill
it and not harm the turfgrass.

Are you *sure* you've positively identified it as S. halepense? What color is
the midvein in the blade?

S. halepense spreads by rhizomes (making pulling the established plants next to
impossible), as well as seed (not letting it set seed will eliminate thst
possibility). It also prefers very wet areas. If this is the case, your best
recourse may be to remove all of the turf in that area (making sure to get all
of the rhizomes out), and re-grading the low area (or providing some other form
of drainage, such as a French drain). Don't just till the area, you'll end up
with possibly thousands of more plants (from segmenting the rhizomes). *REMOVE*
the infected area, completely.

Hi,

I should have given you more information.

I had a very bad case of Johnson Grass when I bought this home. The
first year I did not have time to deal with it. The second year I did
not know what it was, so I diligently dug each weed out by hand. little
did I know that the rhizomes spread like crazy and I was not
solving the problem.

I got two professional opinions and both told me it was Johnson Grass.

Some people consider the "big" lawn care companies such as Tru-Green to be
"professionals". I hope you chose someone with a degree in turf grass
management, such as a golf course superintendant to provide the opinion.

I'll ask again, what color is the midvein down each blade of the offending
grass?

I killed 3/4 of my lawn with Roundup, which they recommended.
This is a five-year process. While I have reseeded, and am constantly
on this awful weed, I am gaining the battle. This will be my fourth
year fighting it.

The patches I killed last August - October are now filling in nicely,
however, come late summer, I know I will be spraying more areas.

What I do is hand paint the leaves of this stuff, and for the most part,
just the plant dies. But, there is some dead grass that has to be
reseeded the next year.

A painstaking method, but I admire your diligence. =)


It does get better each year, but I was mostly reaching out to find out
if anyone else has had experience with this monster, and what they used
to fight it.

We fight it on creekbanks, but it's not an established turf-area. Simply keeping
it cut to the ground level will keep it from
A. developing seedheads, and
B. photosynthesizing, causing the rhizomes to eventually exhaust their food
stores, with the plant eventually dying.

On the rare occasion that it invades a turf area, the area is usually re-sodded,
though there *are* products on the market, available to professional
applicators, that show promise with good results. You, as a homeowner, can't
purchase them
.

I also keep my lawn mowed very short,

Mowing your lawn "very short" can contribute to weed issues. Allowing the
turfgrass to grow a bit taller, and thicker, keeps the sunlight from reaching
the low growing weeds, which eventually die. S. halepense plants that have
already matured are tough though, and will stay with the grass no matter the
height. This will keep them from going to seed, eliminating one way of it
spreading. The height of the grass is also dependant upon what variety it is.
What type of turfgrass are you trying to establish? Fescue? Bluegrass? Zoisa?

and I don't over water it.

Regardless, if it *is* S. halepense, it prefers wet locations. If it's prominent
in an area of your yard, you have *some* kind of drainage issue that should be
addressed. It's also possible that it's been mis-diagnosed by the
"professionals" you contacted. =)


Thanks, and sorry if I mislead you.

No worries. You didn't mislead, rather you left out some information. That's
what discussions are for. =)

Some photos of the plant and areas, posted somewhere online and linked here,
would be quite helpful! There are quite a few that lurk here, who are quite
knowlegable in turf care. =)

Hi,

One of the two professionals I called to look at my problem has a degree
in this type of stuff. He actually owns a weed and feed type store, and
we are so fortunate to have him in our small town.

I don't have a lot of patience, but painting the tips of these weeds is
no big deal, as I don't have that many. My neighbor is doing the same
thing, (thank Goodness or this problem may never go away)and has a good
handle on it.

The stems of Johnson Grass are solid with prominent swollen nodes. The
mid vein is white. I have friends who are farmers and they have tons of
this on some of their land. I imagine the wind and birds create this
nasty problem.

Despite the bald spots I get toward the end of summer, from applying
Roundup (although not as noticeable now as I feel I am getting rid of
the weeds), I still get plenty of compliments on my lawn.
I use a pre-emergent in early March, and the lawn greens up beautifully.
Weeds are not a problem except for the Johnson Grass.

I was just hoping a farmer, or somebody, would know of a secret fix.

Thanks again.

Kate