Firstly - Roundup: Active Constituents: 100g/L Glyphosate present as isopropylamine salt, if used correctly can be a very powerful tool, for those who like to keep their Common Couch home lawns, totally weed free.
Note: DO NOT apply if rain is expected within a 6 hour period. Do not disturb treated species for 7 days. And most certainly, don't use in windy conditions
Now there are 3 Full Strength recommended rates, and they are as follows:
1. Rate per 1 Litre of water - 20mL [used primarily for Annual Ryegrass, Buffalo Grass, Kikuyu, Nutgrass, Oxalis, Paspalum, Bindii [jojo], Sorrel and St. John's Wort et al.]
2. Rate per 1 Litre of water - 30mL [used primarily for Blady Grass, Couch Grass, Queensland Blue Couch, Paramatta Grass, Crab [Crowsfoot] Grass and, Onion Grass~All States except for S.A.]
3. Rate per 1 Litre of water - 40mL [used primarily for Blackberries et al.]
Note that the above rates will give you a Total Kill to the species mentioned along with many others, not mentioned.
So, how does it work on your Couch "Cynodon dactylon" lawns? The actual chemical itself is not a poison [nor does it have a Poison Schedule No.], in fact, it doesn't even have a UN number! I was once told by a very reliable source, that it works by tricking/preventing the plant/grass/weed etc., from photosynthesizing, and of course without photosynthesis, no above ground grown plants can survive. That is how you get the total kill effect. I have known of some highly regarded Golf Course Superintendents, in N.S.W, who have used this half-rate method on their Couch fairways, with amazing results.
All of this is possible, because most Couches on well established lawns are stoloniferous, and usually have relatively deep rhizomes, so, you can actually get away with using the chemical at Half-Rates, as per the table above, to end up with a weed free lawn.
In my case, I simply use a well cleaned "Weed 'n Feed" 5 Litre container, using the no. 2 option above, i.e., meaning I needed to put in 5 Litres of water and add 75mL of Roundup, along with a teaspoon [5mLs] of dish-washing detergent, which acts as a surfactant. I then give the container a very good, gentle shake, and go out and spray.
It is very important to remember that one application of this mixture [employing this half-rate method and whatever container size you use], will not be enough. You will need to do this 2, or perhaps even 3 times [depending on the infestation], to get the desired result [usually a week and a half between each spray & cut], and of course, you can only apply this method during the vigorous growing season, i.e., Early Spring-Late Spring-Very Early Summer. You should also be aware that your Couch, after the first application in some instances, may look a tad bedraggled. Just accept that, as things will quickly improve.
Below are a few pics I took today, after my first application of this mixture on our back-yard croquet lawn. You can clearly see the effect [i.e., the brown spots] this method has had in the weed eradication process. The lawn was double cut after a week and a half of the first spray, but it is going to need another application ASAP [and maybe even a third]. Finally, it is always a very wise thing to keep notes on when and where and what was sprayed, for future reference...
Once the end result looks good to your satisfaction and your Couch is "jumping out of the ground", spread some Shirley's No 17 Fertilizer [or whatever you use] on your lawn, water it in well and then when the time is right, [if you are using A SB 17" e.g.] start double cutting it [or however you mow], and your lawns will be the envy of all your neighbours.
I hope this post helps you, on how to use this excellent and powerful tool...
Here I have used GLY-4 [Round-Up] at half of the recommended strength with two results. This level is actually mention on the label for growth regulation of perennial grasses. Now for broadleaf control I use 2-4-D which also controls our wild garlic. Locals calls it wild onions but I know better.
Annual Grasses are reduced if not eliminated.
Second its acts like a growth on perennial grasses thus reducing the frequency of cuttings.
I was plagued by our sage grass which was taking my field of Tall Fescue. After the first year the sage grass was nearly gone and the second year pretty eliminated it. Of course there will always be few bunches around from wind blown seeds.
Here is one key thing the instructions are for one acre applications so just using a hand sprayer can result in horrible results as you can easily over apply it.
I can only assume that you are talking about USA Roundup labels containers in your post.
I'll try to explain, the basic meaning of my post,
1. Using the rates I provided, will have a detrimental effect an most grasses that have a fibrous root system. These include Poa annua, Lollium perenne, Sporabilis africanus, Digitari didactyla, Elusine indica, to name a few.
2. The same rates will also have an effect on most flatweeds, such as Hypochaeris radicata, Trifolium repens, Cyperus rotundus, although several sprays will be reqiured for this one, Soliva sessilis, Plantago lanceolata, Daucus carota, Taraxacum, Oxalis corniculata and many more.
If you are talking about the instructions for 1 acre applications, I refer you to the statement I made regarding some N.S.W. Golf Course Surerintendents, that have used this half-rate method on their Couch Grass fairways [or the U.S.A term for that is I believe Bermuda Grass], in which the correct amount of water and Roundup were added to the spray tank, after the spray nozzles output were calculated and pre-set to ensure the unit and speed of travel, as such, were set to deliver exactly that was required to do the job.
Having said that, my post was aimed for folks who have a backyard & front Common Couch lawn, who just want to get rid of any weed infestation they might have, using any container they can connect their hose to, using the guide in my post to work out their rate. Note: There are not many of us who have one acre properties in the urban regions of Sydney, although I could be wrong about that...
My humble apologies to you all, for my eagerness in posting the Botanical Names only of the Grasses and Weeds, in my last post. I wish to rectify that, by listing the common names for all, so you can understand what is what.
Firstly, Grasses:- Poa annua~Wintergrass, Lollium perenne~Perennial Ryegrass, Sporabilis africanus~Paramatta Grass, Digitaria didactyla~Queensland Blue Couch, Elusine indica~Crabgraass or Crowsfoot Grass.
Bear in mind that these are only a few, that can get into your lawn, however the Roundup Half-Rate trick will knock most of them, with the only exception being Nut Grass [Which produces a network of creeping underground rhizomes and small tubers], and will usually require the chemical to be applied via. a small paint brush, at full strength.
An update on my lawn. It has had three sprays [at half-rates], and today I double-cut it, [West-East], then spread some No. 17 Lawn Food over it, followed by a through wash in. Mind you, that will still not stop me from giving it a good drink in the early morning of tomorrow.
The two photo's in this post, clearly show the effects of the treatment [chemical wise], and we are due for rain and Electrical Storms in a couple of days time, along with the heat, so it will be interesting to see the results in a week or two's time, when I'll do the first double-cut, then most likely "Top-Dress" it, followed by "The Rub-In".
The eradication of unwanted Grasses:- Poa annua~Wintergrass [Especially, as it was a bad infestation & will definately need a pre-emergent spray, such as Endothall e.g., just before the Couch goes into hibernation], Lollium perenne~Perennial Ryegrass, Sporabilis africanus~Paramatta Grass, Digitari didactyla~Queensland Blue Couch, is complete, as are the Weeds:- Hypochaeris radicata,~Cat's Ear/False Dandelion, Trifolium repens~Clover, Taraxacum~Dandelions, Oxalis corniculata~Creeping Oxalis and most importantly Solvia pterosperma~Bindii/JoJo.
BTW: I am going to be in a constant battle to keep my lawns free of all the grasses and weeds mentioned above, due to the fact that they thrive on almost all of my neighbour's "Council Strip Verges" which are outside of our Properties and are between the property boundries and the road itself [and very probably, their own lawns too]. The majority of these are mowed at the Owner's/Renter's discretion, and in some cases, not at all. And, with that in mind, don't forget that Mother Nature has many ingenious ways of seed dispersal.
Footnote: Have you ever wondered why, after Electrical Storms, your grass, or your local Footy Ground, or Golf Course e.g., looks greener the day after? The reason for that is because every lightning flash gives all plants a brief 100% Nitrogen [N] boost, as it is the initial start of the Nitrogen Cycle.
Thanks for reading this, and I'll keep you up to date...