Is it normal to have crabgrass growing in my new Zoysia sod already just 6 weeks in (lawns, lawn)

[Strongasabear]

It is now 6 weeks since our Zoysia sod was put down. It greened up very nicely. The only concern is we are seeing quite a bit of what looks like crabgrass, especially on the devil strip. Is this normal? After spending the money for sod this is a bit disappointing. As I mentioned before, they did not kill what was previously there....they rototilled and raked and then added topsoil and sod. We are fully prepared to put down pre-emergent in the fall and winter, but is it safe to use a crabgrass killer on the sod now with this heat? Thanks.

[Strongasabear]

I am very nervous about what we spent to have this sod lain and seeing crabgrass/weeds already. What is the lack of prep beforehand, not killing off the existing grass/weeds?

[chorne65]

I had it during the first year... It will go away.. The zoyzia will thicken up and choke out weeds and other grasses. Just spot treat as needed.

[h2ohzrd]

Wait until the Zoysia is established before applying a postemergence herbicide (be sure to read the use directions carefully). I would refer to NC States website for more details on this and other turf problems.
TurfFiles - Turfgrass Information for North Carolina

[scottsheehan026]

This is completly normal. I have put down many Zoysia lawns and every time there has been a problem with crab grass. But in the end with a little help the Zoysia wins.

The crab grass came from the sod farm. The seeds are in the sod and when you water the sod to get it established you germinate the crab grass seeds.

The way I have learned to control it. It is to late for this but it will help others. After you roll your new lawn. Spread corn gluten it should keep the majority of the crab grass from germinating.

After this just pull the crab grass when you see it. You don't want to leave the crab grass ther to grow. It will drop more seeds you have to fight next year. If it gets too out of control then treat it with a post emergent. Post emergents include triclopyr @ 1 per acre and fluazifop @ 0.09 per acre. Mix these 2 together and they should have minimum effect on the lawn. Your crab grass won't know what hit it. After this just treat your lawn 2 times per year with the corn gluten once early spring and again early fall.

[lifelongMOgal]

Sometimes you just have to be vigilant and pull the crabgrass immediatly after you water the sod so as to get most of the roots. The zosia is not strong enough/established enough to choke it out at this point. It will be. Weeds only really grow in zosia when there is a weakness (bug infestation) or bare spots.

[Strongasabear]

Under the direction of the person who did the sod for us, he said to use a post-emergent for crabgrass. I did that (Ortho) early last evening after having watered the lawn early in the day. Today the grass is looking dry and slightly faded in some spots, but the crabgrass seems unaffected. I read on the web to avoid watering for 24-48 hours. Is this correct? Temps here during the day are in the upper 80s. I am getting a little worried.

[scottsheehan026]

Assuming the post emergent you choose to use versus what I told you won't kill your Zoysis it is fine. The crabgrass won't look any different at first. But you will notice over the next few days it will start to turn a purple color. If you notice no ill affects from the Zoysia just respray the post emergent once a week till all the crab grass is gone.

Do not water within 24 hours of spraying and don't mow the grass for 2 days before or 2 days after you spray.

This process should take about 3 weeks.