Right this moment we’re going to take a look at publish emergent weed management for heat season lawns. A “publish emergent” weed management is one that’s designed to kill weeds which have already proven themselves within the garden. If you happen to’ve been right here for some time, you already know that I additionally speak rather a lot this time of yr about pre-emergent weed controls. These are ones that cease weeds BEFORE they present themselves. In my methods, we use each.
In case you missed it, right here is an article I wrote on the pre-emergent weed management I like to recommend known as prodiamine, and the way it works.
St Augustine grass, Bermuda grass, Bahia, Centipede and Zoysia
For publish emergent weed management, I all the time suggest that DIYers attempt retailer purchased weed controls first. It’s because retailer purchased stuff isn’t as concentrated as “skilled” formulations which leaves you extra room for error.
Moreover, skilled formulations usually are not usually obtainable in small batches or small bottles. As a DIYer with a 5,000 sq ft garden, you might not want a whole gallon of weed management that may cowl an acre or extra. As an alternative you want a quart that’s large enough so that you can do 1 or 2 functions and not using a bunch leftover to retailer within the storage.
DIY vs Skilled Weed Management
Right this moment we’re going to take a look at two weed controls which are going to shock you if you get to the tip of this text. They’re Picture for Southern Lawns (DIYer formulation) and Avenue South herbicide from PBI Gordon (skilled formulation).
Consider, these are “selective” weed controls which implies they solely kill choose crops (broadleaf weeds) and never the garden.
Picture Southern Garden Weed Killer focus is available in a quart and prices $14.18
Avenue South Broadleaf Herbicide for Turfgrass from PBI Gordon is available in a gallon and prices $152.87
Do not’ get sticker shocked! Maintain studying and study – I promise you’ll get some good information right here that may enable you to make higher selections on your price range going ahead.
Picture Southern Garden Weed Killer
That is Picture Southern Garden Weed Killer (purple label) and you will discover it at Lowes and House Depot in most southern states the place heat season turf grows. It’s obtainable in a hose finish sprayer possibility and likewise a focus. The focus is what I usually use and I combine it in water in my backpack sprayer. I’ll be making a video right here quickly on my YouTube channel exhibiting you easy methods to combine and spray it. Subscribe right here.
Within the meantime, let’s take a look at the energetic substances and their concentrations, then I’ll evaluate that to an expert formulation with the exact same substances and we’ll make some comparisons and draw some conclusions from it. I guess you the outcomes can be stunning to you!
Lively Components for Picture Southern Garden Weed Killer:
On the entrance of each weed management you purchase, down within the backside nook, would be the checklist of energetic substances. On the Picture for Southern Lawns, they’re:
Penoxsulam………………………………………0.14%
Sulfentrazone…………………………………….0.14%
2,4-D, dimethylamine salt…………………….1.46%
Dicamba, dimethylamine salt ……………….0.41%
The chances you see subsequent to them point out the focus. For instance, the focus bottle is 32 oz. Of that 32 oz, 1.46% is 2,4-D dimethylamine salt. Meaning there may be actually .47 ouncesof that chemical energetic ingredient in the complete bottle.
Verify the mathematics:
32 ouncesbottle
1.45% 2,4-D
32 x 1.46% = .47
Dicamba can also be an auxin herbicide and it represents .41% of that 32 ouncesbottle. Meaning there may be actually solely .13 ouncesof dicamba in the complete bottle. That’s it!
I’m drawing your consideration to this as a result of I would like you to know that these are extraordinarily environment friendly chemical substances! It solely takes a finite quantity of them to kill the goal plant. Simply wait till we dilute it in water (mixing within the sprayer) and then you definitely’ll REALLY see what I’m speaking about. However till then, let’s learn the way these artificial auxins kill as a result of it’s fairly cool.
2,4-D and Dicamba are Artificial Auxins
Artificial Auxins (Group 4) will also be known as plant progress regulators however not in the best way most of you concentrate on it. In our neighborhood, we regularly consider “plant progress regulators” as chems that decelerate the garden’s progress. Guys with bermudagrass particularly will use them in order that they don’t need to reel mow each single day. “PGRs” are used alot on low lower lawns, however that’s a totally totally different class of chems.
The auxin progress regulators we’re referring to with 2,4-D and Dicamba do the alternative. They velocity issues up past the crops’ skill to outlive.
Auxins are systemic herbicides which implies they get contained in the plant both by means of the leaves or the roots or each, and work their approach up, down and throughout the inside of the plant. They get in and velocity up and disrupt the plant’s inner processes.
Broadleaf weeds uncovered to auxin herbicides principally develop so quick they blow up from the within out. At larger concentrations, you’ll see weeds twisting, curling and cupping, typically just some hours after the applying is made.
Image it this fashion: do you bear in mind the scene from Raiders of the Misplaced Ark the place Belloq and Toht’s heads soften and explode when the wrath of God will get into them? It actually appears to be like like that when the broadleaf weed dies. The one distinction is that the weed could take every week or extra to utterly blow itself out however alongside the best way, it appears to be like similar to that clip from Raiders; simply inexperienced and yellow as a substitute of pink.
You’ll discover these two auxin herbicides in cool season garden weed killers too, albeit in several concentrations.
These two herbicides 2, 4-D and Dicamba are very efficient in opposition to broadleaf weeds however they don’t carry out alongside on this combine. There are two different energetic substances driving alongside on this combine that assault the weeds another way.
Sulfentrazone is a PPO Inhibitor
This energetic ingredient (Group 14) represents simply .14% of the whole however it brings a totally totally different mode of motion to the combination. PPO inhibitors are extra contact sort herbicides relatively than systemic. They principally burn the surface of the leaf tissue turning it brown.
Penoxsulam is an ALS Inhibitor
Penoxsulam is a Group 2 herbicide and its mode of motion can also be known as an amino acid synthesis inhibitor. What it does is shut off the plant’s skill to supply a particular enzyme, acetolactate synthase. With out that enzyme, the plant can’t produce amino acids that are the constructing blocks of cells. This herbicide works systematically and is absorbed by means of the leaves of the plant.
Picture for Southern Lawns – a Triple Menace
So we now have 4 energetic substances spanning 3 modes of motion. “Mode of motion” means “how the chemical kills.” As a result of we now have 3 distinct modes of motion within the Picture for Southern Lawns, we now have a broad vary of weeds that we are able to goal and that’s superior for these of us within the south the place there are seemingly a whole lot of various weeds we face.
On the label of Picture, you possibly can see the checklist of weeds that it’ll kill. It’s not going to be 100% efficient on all of them with only one utility, however often with 2 apps, you will get management of most issues that you simply’ll have come throughout.
A few of the widespread weeds I face and have used it on are:
Clover – does very properly right here, however will take 2 functions.
Chickweed – knocks it out quick
Dayflower – for positive takes 2 apps on the excessive charge
Dollarweed – for positive takes 2 apps on the excessive charge
Chamberbitter – does very properly
Doveweed – works for those who get on it early, however received’t do a lot on mature doveweed
Florida Pusley – Florida Snow – knocks it out quick.
Nutsedge (yellow, kyllinga) – doesn’t work properly in any respect
Oxalis – works good and quick
Spurge – works properly, could take 2 apps
Notice: the label says you could depart 30 days between functions. That tells me that not less than considered one of these chems has some residual results that final some time.
How A lot Picture For Southern Lawns to Use
On the label you’ll discover totally different use charges for every grass sort. For St Augustine grass the speed is 5.2 – 8.6 ouncesper 1,000 sq ft. For bermudagrass, bahia grass, zoysia grass and centipede, the speed is 6.2 – 8.2 ouncesper 1,000 sq ft.
Right here in Florida, I like to make use of the best charge for every utility. For my St Augustine grass, that charge is 8.6 ouncesper 1,000 sq ft.
I make the functions utilizing my 4-gallon backpack sprayer and I put 34.4 ouncesof focus into 4 gallons of water and that blend covers 4,000 sq ft.
Final week I made a video the place I talked about among the requirements we use when spraying a garden. A kind of is that 1 gallon of spray combine covers 1,000 sq ft. If you happen to’re confused a little bit on this half, watch that video and also you’ll perceive a lot better!
How A lot Chemical is within the Combine?
Okay so let’s do some extra math. Bear in mind above we talked about percentages of energetic substances? Let’s take a look at that now as we combine it into our 4 gallon backpack (with water) and canopy 4,000 sq ft.
Whole Focus: 34.4 oz – covers 4,000 sq ft
Penoxsulam………………………………………34.4 x 0.14% = .05 oz
Sulfentrazone…………………………………….34.4 x 0.14% = .05 oz
2,4-D, dimethylamine salt…………………….34.4 x 1.46% = .5 oz
Dicamba, dimethylamine salt ……………….34.4 x 0.41% = .14 oz
Consider, this is sufficient to kill weeds throughout 4,000 sq ft. So for example, there may be solely .05 ouncesof Penoxsulam within the combine to go throughout 4,000 sq ft. Are you able to see now how focused these chemical substances are? There’s hardly any happening but it’s nonetheless killing all these weeds you spray.
It Doesn’t Take A lot!
This goes again to the chemical substances being scary to some folks. I wrote about this in depth final week on the weblog. A technique to consider that is what I name “kilos on the bottom.”
As new chemistries have been developed over time, scientists have discovered energetic substances that work properly with VERY little precise “kilos on the bottom” wanted, or mentioned one other approach, a little bit can go a LONG approach. This leads to a lot much less whole chemical output within the garden.
If you happen to take a look at it this fashion, you’re actually not spraying that a lot chemical in your floor. It’s principally water. Certain, you possibly can odor the chemical substances. Weed controls have a particular aroma, however there may be solely .05 ouncesof Penoxsulam in a whole 4 gallons of water. (4 gallons is 512 oz).
Proportion smart it appears to be like like this:
4 gallons = 512 oz
.05 / 512 = .000098 % Penoxsulam within the combine.
See how finite that’s?
Of that 512 ouncesof spray combine, .0000098% of it’s Penoxsulam chemical.
And but it will probably kill weeds in your garden even at that very low focus. Science is fairly superior proper?
Simply consider, it’s not doing this by itself. There are nonetheless 3 different energetic substances in the identical combine however they’re additionally at VERY low concentrations. As a result of they aim crops (weeds) are being hit from 3 totally different modes or websites of motion, you will get away with an excellent low focus of every. That’s good!
Skilled Weed Management – Avenue South
I hope you had enjoyable with all that math as a result of subsequent we’re going to take a look at an expert formulation of the exact same energetic substances. This formulation has a band title known as “Avenue South” and it’s a very fashionable weed killer used {many professional} spray companies.
Listed below are the energetic substances with their concentrations:
Penoxsulam. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.70%
Sulfentrazone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.70%
2,4-D, dimethylamine salt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.28%
Dicamba, dimethylamine salt . . . . . . . . . . . . . . . . . . . . . . . . . . 2.06%
Instantly you’ll discover the concentrations of every of the energetic substances is sort of a bit larger. Will this get higher outcomes? Presumably, however we don’t have sufficient info to find out that but. We’ve to learn additional on the label and study what the advisable utility charges are from the producer, PBI Gordon.
For St Augustine grass they’re telling me that the “excessive charge” is 1.8 oz / 1,000 sq ft. That’s fairly a bit lower than the 8.6 that’s advisable because the excessive charge on Picture for Southern Lawns. So let’s do some math to see if we web out at the next quantity of chems.
In my 4 gallon backpack, I’ll want 4 x 1.8 = 7.2 oz
That interprets to:
Avenue South
Penoxsulam. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . 7.2 x 0.70% = .05 oz
Sulfentrazone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.2 x 0.70% = .05 oz
2,4-D, dimethylamine salt . . . . . . . . . . . . . . . . . . . .. . . . . . . 7.2 x 7.28% = .5 oz
Dicamba, dimethylamine salt . . . . . . . . . . . . . . . . . . . . . . . . 7.2 x 2.06% = .15 oz
Right here’s how that compares to the max charge combine in Picture for Southern Lawns:
Picture for Southern Lawns
Penoxsulam………………………………………34.4 x 0.14% = .05 oz
Sulfentrazone…………………………………….34.4 x 0.14% = .05 oz
2,4-D, dimethylamine salt…………………….34.4 x 1.46% = .5 oz
Dicamba, dimethylamine salt ……………….34.4 x 0.41% = .14 oz
They’re the identical!
What’s Extra Costly?
Picture for Southern Lawns vs Avenue South Herbicide
Understanding this, now we are able to decide solely primarily based on value. Since they ship the very same quantity of energetic ingredient with every utility, which considered one of these is cheaper? Is it the DIY/house owner focus from Picture or will or not it’s the skilled formulation Avenue South from PBI Gordon.
Let’s have a look.
Picture for Southern Lawns Focus
Measurement: 32 oz
Value: $14.18
Software Price: 8.6 ounces1,000
Protection: 3,720 sq ft
32/8.6 = 3.720
$14.18 / 3.720 = $3.82
Value per 1,000 sq ft = $3.82
Avenue South Herbicide Focus
Notice: within the pics right here I present a small pattern bottle of Avenue South. That isn’t obtainable for retail sale. The smallest you possibly can truly purchase is a 1 gallon jug. That’s as a result of this product is marketed to garden professionals who usually combine in giant tanks for truck mounted skid sprayer functions
Measurement: 128 oz (1 gallon)
Value: $152.87
Software Price: 1.8 ounces1,000
Protection: 71,111 sq ft (an acre is 43,500 sq ft)
128/1.8 = 71.111
$152.87 / 71.111 = $2.15
Value per 1,000 sq ft = $2.15
Conclusion
Within the case of Picture for Southern Lawns vs Avenue South, for those who can afford to purchase the gallon up entrance, you’ll lower your expenses in the long term. Nonetheless, you even have to think about the scale of your garden. When you’ve got a 5,000 sq ft garden within the suburbs and you buy the Avenue South, you’ll get 14 functions from it. And that’s if you must utterly blanket spray.
1 gallon covers 71,111 sq ft
5,000 sq ft garden
71,111 / 5 = 14.2
Virtually talking, I extremely doubt you would wish to make that many blanket functions over time. You’re in all probability going to finish up blanket spraying 1 time per yr and spot spraying the remaining which implies this 1 gallon jug will final you greater than a decade. That’s additionally in all probability for much longer than the shelf lifetime of the product itsel.
So my suggestion for DIYers is to stay with the Picture for Southern Lawns obtainable to DIYers at any large field retailer.
I’ll see you within the garden!
