Killing Weeds In St. Augustine Grass

A common question that I usually get is what’s a really good weed control that can be used on st. Augustine grass. As you know, St. Augustine is pretty sensitive to a lot of common herbicides.

I’m glad you asked because eveybody may need to use some weed control on their lawn sometimes. As for me, I just had to use it not so long ago, from a couple weeks after our initial planting and our initial shot of starter fertilizer and we’re in need of a weed control spray now.

No matter what precautions you take, you’re gonna get weeds in this grow. It’s just going to happen, there’s nothing you can do about it, because remember what we had here was a hundred percent salad bar.

Killing Weeds In St. Augustine Grass

There are probably bazillions of weed seeds in this lawn that have just been waiting to germinate. There was just other weeds in the way all these years. So now they’re having a party.

And we’ve done our part: we put down a good pre-emergent, we put it down on time, we got it down quick but there’s always going to be some escapees. There’s always going to be areas that just don’t take as well. I mean it is sandy soil and so it’s to be expected that with shifting sands, we’re gonna have some breakthroughs.

In addition to that, you’re watering a lot and the more you water,  the more it does tend to water through your pre-emergent. So basically, what I’m saying is all of this was expected, it’s now time to go on weed control. We’re going to do it with a really good product that’s going to give us some really good results. It’s going to help things keep going.

organic Weed Control

Factors To Consider When Killing Weeds In St Augustine Grass

We need to be selective about this and be careful. Because the one thing I want you to realize is even though this herbicide that I’m introduce to you is considered safe for st. Augustine, if it is over-applied, it can stunt growth and maybe even bleach it out a little bit.

The key here is to be methodical about this. Plant it out, walk a grid back and forth, and back and forth and keep your wits about you. Pay attention to what you’re doing, keep an eye on where you’re at and if you have to leave the area, make sure you mark it really well, because we don’t want to over apply it.

In fact, we don’t want to even hit our plugs if we don’t have to. So let me show you the strategy we’re going to use to go ahead and take care of this.

As for me, my plugs were installed 19 days ago. We are getting some really good runner growth. What’s interesting is the Palmetto is not quite as vigorous as the Bitterblue. This is all Palmetto and you can see the runners starting to shoot off. That’s going to be very important for you to understand and to pay attention to.

As we go and spray our weeds, the weed control that we’re going to use is okay for st. Augustine but it is not okay until the st. Augustine is established. Something to think about here is a plug itself is established. It’s got a full root zone and it’s got full top growth.

However, the runners that it sends out are not fully established, they are still in a fresh new state so to speak, and they can be damaged by herbicide. But you’re going to see that the weeds are intermingled around those runners. So we are going to get some loss. It’s a give and take, but again we’re going to use techniques to minimize the loss.

Things You’ll Need

How To Kill The Weeds

The first thing you need is a good quality pump sprayer with a flat fan tip nozzle, which is the key to accomplish this mission. So I got a three gallon sprayer and I did that on purpose and you’ll see later when it comes to our fill why I did that.

Once you’ve got your pump sprayer, go ahead and fill it 1/2 to 3/4 full with clean water. Then the two things you’re going to need are a surfactant, in which case I’m going to use the dishwashing liquid, and you’re going to need a herbicide called Blindside.

Blindside is not an inexpensive herbicide but it’s well worth the money because it’s extremely effective. And the reason I got a three gallon pump sprayer is because the mix right here is 0.15 ounces per gallon of water.

This is a tip and pour bottle or what I call a tip and sip, because it’s really hard to get 0.15 ounces tipped in there properly. It’s much easier to get point 4 or 5 ounces which would be the proper amount for 3 gallons and that’s why I went with a 3 gallon sprayer. Of course you need to wear your personal protective equipment like eye protection, long sleeves, long pants, rubber boots and rubber gloves.

Blindsides is a great herbicide, it actually gets inside the weed systematically in two different ways. It absorbs through the leaves or foliar as well as through group uptake. It also works very quickly, I’ve seen results within five days of spraying. The other thing about blindside is that it has some extended soil activity, so it can actually work as a pre-emergent in some cases. The two active ingredients are offenders owned and Metzl Fearon methyl.

Other Herbicides

Blindside is going to be a little expensive so what you can get instead is this MSM turf herbicide. What you’re going to get here is the metal fear on methyl which is again one of the active ingredients in the blindside. This works a little slow on its own and there are a few things that it won’t get but it is a very inexpensive alternative. It has extremely low use rate so if the blindside doesn’t work for you also, give this a consideration. In case you’re wondering, yes, both can be used on Bermuda grass too.

Tips For Killing Weeds In St. Augustine Grass

As far as spray technique goes now, you’re gonna literally paint between the dots, that’s the idea. What you want to do is spray it up and down the rows and avoid the actual plugs as best as possible.

Additionally, you may want to try to avoid your runners. This is not going to be possible in all cases because the weeds grow up around them. But the idea is to be careful and try not to get this product on the st. Augustine or on your new runners. If possible, some die back is going to occur.

After 5 days of application, you can see some of the runners have suffered but the weeds all around are dead. Key being this: the weed is completely dead but my plug is still alive and it can continue to send out more runners.

The ones that are stunted will probably come back themselves. This is why I said it’s a little bit of a give-and-take and you have to be careful. I walked up and down every single row and sprayed in between wherever I saw weeds.

In the cases where the weeds are grown up completely around the plug, you’re just going to have to go ahead and spray it. The plug itself will be fine but again you might stunt some of those new runners. The key here is to keep your sprayer pressured up to keep that fan tip nozzle doing what it does best. And that is putting down a really nice fan of product in a controlled way.

As a rule, you’d like to give this 24 hours to dry, so you wouldn’t want to water. But I use a surfactant which is going to help to stick a lot quicker. I’m going to go ahead and skip my morning watering, so I’ve sprayed this in the evening about 7:30, when I’m finished with my application.

Wrapping it up

St Augustine grass can be quite good at outcompeting many weed types. However, once a Saint Augustine lawn begins to lose some of its health and vigour, then many weed types can invade the turf very quickly and abundantly. Hope that the tips above may help you eliminate the weeds in your lawn.

Killing Weeds In St Augustine Grass

(2) comments

Add Your Reply