GasganoFJ60

Heres one for all you terf and lawn care professionals.

I work for the housing department of a university and we have run into an infestation of Johnson grass around one of our apartment buildings. The sprinklers have been inactive most of the summer due to water restrictions but now I got them up and running again and everything is bouncing back real nice, except for Johnson grass! Its sprouting up everywhere! We're a low budget grounds team and I was wondering what can be sprayed that wont harm St. Augustine and Bermuda but knock out that Johnson grass.

Ive googled around for answers but I just cant find any straight forward answers.

Ill take any tips or advice you guys got.

justagoodolboy

Stuff Called MSA will take care of that problem. I spray my place about once every couple of months for that same reason. You can get it at just about any feed store. Just be sure to mix it right.

Grayzone & 24d will do the same, but its a little more likely to kill all the grass than just the junk grass. I have sprayed with 24d before and killed thistles, johnson and bahia grass and my native bermuda grew like crazy. but it took me an hour to read the booklet that comes with it to make sure I mixed it right!

AggieJustin

Are you referring to MSMA? If so, it will also take out your St. Augustine.

I've used it on my lawn to treat my Dallis Grass, but I have to steer clear of my St. Augustine or it will kill it.

Purplezr2

Gordons Trimec Plus is what we use in the Golf Course business, not sure if its for prchase to home owners.

GasganoFJ60

Yeah, thats what I'm afraid of but the former grounds keeper told me that anything with MSMA will kill the Johnson grass and it will yellow the St. A. and Bermuda but only for a week or so then it will come back. He said its all in how well you apply it.

But I dont know. Thats just what he has said but I wanted to get some more opinions.

Anyone else have any experience with it?

justagoodolboy

Yep, MSMA - funny, after posting yesterday I went into my shop and saw the bottle and realized I left out a sylibol. I use it exclusively for control on Johnson & Bahia grass in my bermuda pasture/yard. It does not seem to affect the bermuda. Not sure about the San Augustine though.

I've got a friend thats a horticulturist - let me give him a ring.

GasganoFJ60

Yes, would you please call a professional? It would be much appreciated.

Break Away

Crossbow does a excellent job on crabgrass---does not harm fescue.

SolarExpress

Spade works nicely. If aimed just right it wont do a thing to the St. Augustine. I have 2 ac. that only gets fertilized maybe once every two years. No weed and feed. I noticed that a nice thick St. Augustine will choke out just about any weed.

justagoodolboy

Talked to my buddy. He said there is a product called Cimarron, which is generic Ally, that will kill bahia and crabgrass but not harm bemuda. He is not sure if it will kill san agustine or not. He said thats something you'd have to check out on the label - he could not recall for sure.

He said it will probably be hard to find something that will kill johnson/crabgrass and not kill san augustine. He's calling another friend to check on something else plus confirm about the Cimmarron. The problem is most of the chemicals that kill weeds are designed to kill just that, but prosper a production type coastal grass like bermuda/alicia, and with him being a farmer, he's not to up on whats good on turf type grasses.

Thought I'd share an update. We'll see what he comes back with.

GasganoFJ60

Thanks a lot. Its much appreciated.

I checked on that chemical called Trimec and its sold at our local Tractor Supply, pretty cheap too, but a license is required to purchase it.

Hmm...what to do, what to do.....

AggieJustin

The problem is that anything meant to kill grassy weeds will probably knock out St. Augustine, carpet and centipede grasses. Plenty of stuff to kill broadleaf weeds in those grasses, but hard to find anything to work on grassy weeds.

king d

the deal with johnson grass is it is a mother to kill.even if you pull it up it can and usually wil redelevope a plant from what minor part of the root system is left.the more you mow it the bigger the roots get trying to get more nutrients moisture ext...the best way to get rid of it is to selectivly once it heads out clipp the seed head off and trhow it away.you can use a low rate of glyphos say 4-6 oz,it will take out the crab grass and the bermuda will be fine,however the st augustine may not like it..shouls make the johnson grass awefully sick as well

king d

2-4-d is not a grass killer.it actually inhibits any grass killing product applied at the smae time due to its antagonistic nature.by grayzone do you mean gramoxone?if so this is a paraquat product whci is great for small weeds but for grasses it burns so fast they come back rather quickly.

GasganoFJ60

I appreciate all ya'lls help with this. Im really not to worried about the St. Augustine. After walking the apartment complex this passed week I noticed only some, very few, areas have St. Augestine and I figure for those areas I can continue hand pulling those small spots. But Id say 80% is Bermuda with spots of crabgrass. Someone was telling me that for the best results with crabgrass, I'd need a spray that will be absorbed by the roots, not the leaves. Is there any truth to this? Is there a difference with most OTC sprays?