Thank you for your question.
You'll need to use an herbicide product such as Roundup, Kleenup, or
Weed and Grass Killer. These products will contain the chemical
called glyphosate. Glyphosate is the name of the active ingredient
and it's a non-selective weed killer.
Zoysiagrass is a warm climate grass and is extremely difficult to kill
but it can be done!
Follow the directions on the product you buy. Basically, if you have
a very large area you'll want to buy the concentrated form and mix it
with the proper amount of water.
Here are the steps you'll be taking to completely eradicate Zoysiagrass:
1. Buy a 2 gallon pump-up sprayer container for application and use
the fan tip for large broadcasting. For the sake of this discussion,
we'll assume you've purchased Roundup.
2. Pour the recommended amount of Roundup into the spray pump
container and then add the recommended amount of water. (Make up a
large amount because you'll be applying this more than once!)
3. Never apply on a windy day and try to go out in the morning after
the sun is out and when the weather is going to be nice and warm.
4. Broadcast the Roundup. Spray liberally and then leave the area.
Until the area is dry don't let animals or children out onto the lawn.
5. Wait about 2 days and then water the area liberally.
6. In a few days and you'll start to see some dead grasses.
7. Rake them up and throw away.
At this point, you'll again perform step 3 through 7.
Do the same steps as mentioned above repeatedly *all summer* long.
Eventually you will see more and more results.
It might take another warm season where you'll need to perform the
process again and again.
It can be done, it takes persistance and in the meantime you'll have
nothing growing where you're applying Roundup to the ground.
The reason you want to water liberally, is to get the herbicide to
absorb into the grasses and soak way deep in the ground where it
affect the roots.
Remember to store your product and the spray pump away from animals and children!
Roundup Weed Killer Popular with Gardeners
"One of the most popular weed killers for home garden use is a
material called Roundup. Sold under various trade names including;
Roundup, Kleenup and Weed and Grass Killer, the common chemical name
of this product is Glyphosate, which will always appear as the active
ingredient on the product label. Roundup is a systemic herbicide. This
means that it is absorbed into the plant and is carried internally
through the plant. Because of it's systemic character, Roundup is
applied to green leaves and green stem tissue. It is absorbed and
moves through the entire plant, killing it, roots and all. This is
especially beneficial in controlling perennial weeds. When the roots
are dead, the weed will not regrow.
Roundup is most effective on perennials including weedy grasses such
as wild Bermuda grass and broadleaf weeds like plantain. It is
"nonselective", meaning it will kill virtually any green herbaceous
plant it comes in contact with. It can be used to spot treat weeds in
the lawn, edge trees, control weeds in shrub beds, and eradicate weeds
that pop up through patio blocks and gravel driveways.
Unlike many weed killers, Roundup has no effect on the soil and is
safe to use to eradicate weeds prior to sodding a new lawn or planting
a landscape bed. Applications of Roundup must be made carefully. Any
green plant tissue will absorb this product, not only leaves but also
green twigs and trunks, like those of Palo Verde trees. Sprays must be
directed to avoid contact with desirable plants. The best time to
spray is in the early morning when the air is calm. When spraying in
"too close for comfort situations", use a piece of cardboard to shield
desirable plants from the weeds you intend to spray. Tall weeds in a
shrubbery bed can be bent over and sprayed on the ground.
After applying Roundup, give it time to work! Because it is a systemic
it must be absorbed by the leaves and moved down within the plant to
it's roots. All this takes time, usually about 7 to 10 days. Plants
will begin to yellow up and then die. Do not pull or hoe the weeds out
until they are completely dead. If weeds are emoved before the
chemical can move into the roots, they will just regrow.
One final precaution, Roundup, like all other pesticides should always
be used according to label directions. Use the dosage recommended. The
adage "if a little is good, a lot is better" does not apply with
pesticides including Roundup. Overdosing will cause the tops of weeds
to die before the Roundup is moved into the roots. Roundup
(glyphosate) is available for purchase in several formulations of
varying concentrations. The most concentrated forms contain 41%
glyphosate, while the least concentrated premixed and ready to use
products contain only .5%. If you are planning to use the product
frequently, a more concentrated form would be the best buy even though
the initial cost is more."
HOW TO ATTEMPT TO KILL A ZOYSIA LAWN:
"A Glyphosphate such as Roundup is your first weapon to kill out zoysia.
You need to make sure the zoysia is growing juicy and lush and green,
before spraying. Very critical when trying to kill any of the warm
climate grasses, to make sure they are actively growing or else the
plant will not absorb much of the Glyphosphate. Most people
think they are trying to kill the grass, so watering and feeding it is
the last thing comes to their minds.
But, if the zoysia is stressed for water and fertilizer or it is too
early in the year so it is not growing much, the spray is a waste of
money and time as the grass plants will not absorb the poison spray
while they are semi- or fully dormant.
And, even with all this, it is still most likely they will need to
spray two or more times to get full kill.
Spray once and leave the grass alone for a week or two to allow full
absorption and transfer to the roots of the poison. Then rake and
mow off the dead grass, and immediately water well and deeply to see
if any is left alive to regrow. Repeat as necessary. Once any
remaining stems green up and are lush again, spray again on those
patches and repeat the wait period. This is usually enough to wipe
out any persistent warm climate grass.
Some extension agents recommend (and I have heard this from turf care
professional also) to add some fertilizer to the spray tank, and also
some sort of a surfactant. The liquid fertilizer (even dissolved
Miracle Grow works) stimulates the grass plants to absorb more poison,
and to continue active growth so the poison can act more effectively.
The surfactant (a few tablespoons of liquid dish soap is a cheap
substitute) will allow the spray to spread and stick on the leaf
surface, rather than just beading up and running off before it is
Last thought, and this is based on success that Bermuda seed growers
have when they are discontinuing an old field and converting it to
lettuce, etc. production. They till the field up in mid winter and
leave the soil clumps and roots and rhizomes exposed. Any winter
freeze will help knock the grass and kill more of it. Then usually
they will till the soil a couple of more times in winter to keep
exposing new portions of rhizomes and crowns.
BOTTOM LINE: Is that Zoysia because of its deep and persistent root
system (Rhizomes) is VERY DIFFICULT to get complete kill on. Good
"To get rid of Zoysiagrass, you must kill it all with an herbicide
such as glyphosate (Roundup, Kleenup, etc.). As an alternative, you
could try to smother it by covering the entire area with black plastic
or by piling leaves on it for several weeks."
"We are tired of Zoysia looking dead for half the year and crowding
out our green grass nearby. Will Roundup kill the zoysia? And if so,
what do we do after that? CAn we just dig it up and plant other seed,
or do we need to put in sod? We've dug out the zoysia down to about a
foot, three times. It just comes back and chokes out the new grass we
"Roundup will kill zoysiagrass and should really be used before any
excavation. Because it's easier to get penetration when there is
plenty of zoysia leaf canopy on the surface to take up the Roundup
Also, one application of Roundup isn't enough to kill zoysiagrass or
other perennial grasses such as bermudagrass. Plan on three good
applications to get about 99% of it. Then excavate the rest."
Plus personal knowledge