Weed B Gone for St. Augustine Grass
 

I have a small yard in my courtyard villa that has St. Augustine grass (sometimes called crabgrass by others). Last year I started getting a weed problem, so in the off season, I pulled every weed I could find. This year the lawn came up green and lush and I thought I had beat the Florida weeds for once. No such luck. Now I have weeds spread all over the lawn, some of which attach their seeds to our dog every time she goes out (several times a day). In the early summer I bought Weed B Gone for St. Augustine grass and applied it as directed. No obvious change. I applied it again last month. No obvious change. The weeds are thriving. I’m about to use Spectricide Lawn and Weed Killer which will kill everything, and I can lay sod on the dead areas in the spring. But before I take that drastic action, does anyone know of a product that actually works? I think plain water would work as good as Weed B Gone.

go talk with Tommy at the Wildwood Ace Hardware first... he can make great suggestions for the correct stuff to use and when.

Assume you mow your own yard? If not, that could be the source of your weeds from others yards when the contractor mower jumps yard to yard to yard.

Thanks, I do mow my own lawn. I’ve always mulched it but this year I’ve used the bag to minimize seed dispersal.

Thanks. Which Ace Hardware?

This is not the time to kill weeds in your lawn. Wait until early spring then use Scott's fertilizer with pre-emergent weed and crabgrass control suitable for St. Augustine grass. After that what ever weeds come up use a granular weed and crab grass killer and problem will be solved.

Most herbicides are only effective during an active growing season. Try again in spring. Your lawn and weeds should be pretty much dormant now anyways until then.

I've found that the "Roundup for Southern lawns" is an effective product for weeds in St Augustine grass, but what the OP was using was probably fine in the first place.

Is there any way to get a load of dirt? I don’t know kind of grass we have now, actually it’s brown and almost non-existent, but we are planning to put down St. Augustine. But my husband wants to put down dirt first because he says the ground is all sand, but I don’t know where to get a load of dirt.

Dirt Cheap, Summerfield

Dirt Cheap

I found that a herbicide called Atrazine works well for broadleaf weeds and does not harm the St. Augustine. I buy it online at Domyown.com. Mix in a hand bottle sprayer for spot treatments. And I use a pre-emergent in April and Nov as I was instructed by the UF agriculture extension agent (Master Gardener) at Sumpter County to prevent new weed seeds from sprouting. Comes in granules and spread like fertilizer. My lawn is doing much better now.

I attached a lawn care guide that the UF lady sent to me.

RoundUP
 

Do no use RoundUp on lawn grass. It kills ALL vegetation....weeds, grass, any living plant. Don't do it!

I hired TrueGreen to take care of our small TV lawn. But when we lived on acreage I used Atrazine.. It works well for broadleaf weeds and does not harm the St. Augustine, or other grasses.

In the spring use a weed and feed fertilizer. Don't forget to treat your lawn with a pesticide. This area has a huge problem with chinch bugs, and it will also help keep bugs out of your home.

As others have said go to Ace and ask for advise to buy these products.

No weed problem is “solved.” Better controlled but not “solved.”

Pay attention to what the original quoted post said "Roundup for Southern Lawns." It is a variation specifically meant for weed killing, and does not harm St. Augustine grass.

However, Atrazine is a much better choice, and is also safe for St. Augustine grass.

Since the pre-emergent didn't work sounds like your weeds are perennial. For St Augustine Provista use glyphosate 41% to kill the weeds. Tractor Supply and Rural King are the only places around here that sell glyphosate. If your lawn is not actively growing then mix the glyphosate at 50% or wait until spring to apply.

Most it with water then sprinkle baking soda over it. A kitchen sifter works well for this. Sounds crazy but kills weeds. May yellow grass but not kill it. .

You can also buy Hi-Yield Killzall which is 41% glyphosate. They sell that at all the home improvement stores and Ace and also Amazon.

I was told that I have Floratam St Augustine by the original installer but all my neighbors say they have ProVista. I bought some Killzall and tried it on a test area in my backyard and it worked great. It killed crabgrass, Bermuda grass and torpedo grass but didn't harm the St Augustine so I must have ProVista.

The Lawn Care Nut utube channel does recommend Roundup for Southern Lawns and Image for Southern Lawns for winter weeds in Florida. They have the same herbicides but with different application rates.

I have my lawn treated. My neighbors on either side of me do not. They have weeds that find their way onto my lawn. How would you deal with that?

Are they round shiny and flat about the size of a silver dollar? If so that’s dollar weed and special weed killer needs to be used.

Recommended by a lawn care professional
 

image southern lawn weed killer. 6-8 oz per gallon. Then Scotts for southern lawns with pre-emergence. The bad news, I'm not sure it's recommended this time of the year.

Well be careful. If you live south of 44 most but not all St. Augustine is Provista variety which is glysolphate tolerant which was the active ingredient in the old roundup and will kill anything but the Provista. Always mix it with a surfactant for better results. Atrazine is also very good for broadleaf weeds in any type of grass, post and pre emergence.

Roundup for lawns is very effective

How is the Spectricide or any other chemical going to work
out for your dog ? :(

Get rid of the St. Augustine and replace with Zoysia. St. Augustine is a weed!

https://i5.walmartimages.com/asr/01c...c3fedd26d.jpeg

This stuff actually works

"Roundup For Southern Lawns" one of the all time great love stories.

I have a new home in the Village of Shady Brook. The landscaper hired by TV told me on the phone I had Floratam St Augustine grass and to NOT put Roundup on the lawn. My new lawn service told me the same thing.

I use a produce called Q4. Mix it as directed and follow the directions about mowing and your weeds will be gone. It won't be over night but it works. It's not inexpensive but great stuff.

First, make sure your lawn weed killer is safe for the variety of St Augustine grass we have here, which is Flortam. Then make sure the weed you want to kill is listed for your weed killer.
Look for a product called Image for St Augustine grass and Centipede grass at Lowes

I've lived in Florida for 40 years and the Empire Zoysia I have here is the worst grass I've ever had. Wish I had St. Augustine.

If you want to learn from some experts, and not simply take random suggestions from neighbors, read the material from Florida based horticulture experts. The first offers a broad view of weed management with very specific recommendations. The second dives deeper into how herbicides work, along with detailed descriptions of almost all herbicidal products.

Especially: Weed Management Guide for Florida Lawns
and: Turfgrass Herbicides: Mode of Action and Resistance Management

BTW. I would rather hear from these academic specialists, than from the lawn care professionals who only want to sell their own service, or the random guy at the store who probably doesn't have enough background, Tommy at Wildwood Ace Hardware excepted. :)

You can buy bags of dirt at Home Depot.

Go to Ace Hardware (or online) and buy Roundup for Southern grasses. For the first application, use the lowest recommended rate. If that doesn't stop the weeds, make the second application at the highest recommended rate. At the higher mixture rate, the St. Augustine may show some "yellowing", but it will survive.

I always used Scott's BONUS S...It's a little expensive but works for the weeds and doesn't kill the grass....It's a granule and you just need a spreader to apply it to your lawn...It always works to take away the weeds for me.

NOT True!
 

Wildwood

Hi,

The best defense against weeds in St Augustine grass is thick, lush, well fed St Augustine grass. Everyone mentions weed killer, but the real answer is feed, feed, feed the St Augustine grass. The grass will smother out most of the weeds. Here’s some suggestions:
1- I use a combination of Scott’s for Southern lawns and Sunniland organic. For the first year alternate these products EVERY MONTH! Yes, every month.
2- your St Augustine needs 1-1.5” of water EVERY WEEK. The only time I vary from this is when temps drop into the thirties. St Augustine does not go dormant here unless we have freezes. I water twice a week, 1/2 x3/4 “ of water per water cycle. ( set out a dozen tuna cans to measure each irrigation zone)
3- Mow your St Augustine at NO LESS THAN 4”! Always! Then mow so you remove only 1/3rd of the grass blade. Yes, during the warm weather, that means twice a week.
4- I use Scotts weed and feed for Southern lawns in the fall and early spring. I hand-pull the weeds as needed throughout the year. The ONLY time I use a “ weed killer” is to spot-kill stubborn weeds like dollar weed.

The thriving St Augustine will smother a majority of the weeds. Here’s my schedule. I have the thickest, healthiest, deep green lawn in my neighborhood.

February- apply Sunniland at the bag rate + 30% ( Sunniland organic will never burn and is also great for plants and trees.
March- Scotts weed and feed for southern lawns at the suggested bag rate
April- Sunniland organic at the bag rate +30%
May- Scotts fertilizer for Southern lawns at the suggested bag rate
June- Sunniland organic at the bag rate + 30%
July -Scotts fertilizer for southern lawns
August - Sunniland organic bag rate + 30%
August - Scotts fertilizer for southern lawns
September- Sunniland organic bag rate +30%
October scotts weed and feed for southern lawns
November-Sunniland, double the bag rate!

Done feeding the lawn until February. It will take a solid year and aggressive feeding before you see results. All of your hard work will pay off. Your lawn will be thick and lush and mostly weed-free. At this point, you can feed a little less to maintain. Rather than alternating your feedings every month, go to alternating the Scotts and Sunniland every 6 weeks.

I haven’t mentioned fungicides ( scotts disease X or pest control) do your homework on these too.

Right now, December 1st, my St Aug is thick, green, and lush, cut at a minimum height of 4 “, and relatively weed-free. Most people who ask me what I do are not willing to do the work and end up with mediocre lawns with weed problems. Do the work and reap the benefits!

Good Luck
PS: "The poof is in the pudding". You are welcome to private message me and see my lawn if you want. I would be happy to meet you. I live south of 44 in the Village of Linden.

To kill the weed growing in my grass, I use Spectrecide "Weed Stop For Lawns", which comes in a BLACK bottle. If used in the prescribed dilution, it won't harm your grass. I use a pump-up sprayer and spot-spray the weeds in the grass. After several "spot treatments", over a 1 or 2 week period, you will only need to spend a few minutes a month doing future spot treating to keep the weeds at bay.

Crabgrass and St Augustine are NOT the same thing…not even close. Get Scott’s Weed & Feed for St Augustine (purple bag); apply as directed. Done deal.