General mix rate for Roundup / glyphosate 41%

What kind of mix rate should I be using (in ounces per gallon of water)?

The instructions reference all kinds of weeds and relates the ratio to what you are trying to kill. I’m not a botanist, I just want to kill weeds.

I’ve been using 2 ounces per gallon, which seems to bring on a good kill within about 7-10 days.

Now today, I read somebody talking about 4 ounces per gallon and the logic being this ratio kills every thing and is so powerful it minimizes the chances of allowing any weed to build up resistance. That seemed very high to me.

I don’t know if this ratio is even allowed per the instructions, but it just got me thinking is my ratio even right? I don’t know where I even got that ratio from. I’ve just been using it and don’t remember where I came up with this 2 ounces per gallon.

What’s the “general grass/weed” recommendation?

Grouse

For spraying plots I also use 2 oz per gallon and it works very well. The only time I go stronger is when I have very mature weeds or spraying thistle or buckthorn, then I go to 3 oz per gallon. For a normal kill of weeds 2 oz per gallon is perfect.

Are you adding anything but gly to the mix? Last year I started adding Hel-fire form Helena chemical company to the mix. It speeds up the kill time, makes the gly stick to the weeds better and helps with hard water issues. Some guys use AMS(ammonium sulfate) for the same reasons, but I have heard it’s hard on the sprayer.

Sticker, appreciate the confirmation that I’m not out in left field on the mix ratio.

I’ve been buying either the Tractor Supply 41 gly with surfactant already mixed in or the Rural King brand, also with the surfacant. Rural King had the 2.5 gallon jugs on sale for $30 last year, which to me seemed like a pretty good price. I probably should have bought more, maybe tractor supply will have a sale.

Grouse

For spraying our plots we use 1.5 quarts per acre. I can’t tell you the exact amount per gallon, but it takes roughly 25 gallons of water for me to spray an acre. This may be a little lower than 2 ounces because the roundup we use has 53% active ingredient and I’m assuming yours has 41% active ingredient.

the 2-4oz/per gallon is about right. Key is to have a mixture strong enough to kill the worst of the weed problems. Grass and other wimpy stuff will die off easily with 41 @ about 1.5 oz / gallon with a light spray.

I run into a lot of Sowthistle, Leafy spurge, Canada thistle, Prickly lettuce, and Spear Thistle. Some of these take multiple sprays to kill off when using the minimal applications. So we changed our ways and went with the much more expensive stuff. We buy it through our local co-op and get a reasonable rate. I think it is in the 50+% of active ingredients and we mix at 3oz/gallon and apply at a pretty high application rate (don’t remember the qty/acre). In 3 days, there is no doubt that EVERYTHING is dead.

TheFamousGrouse wrote:

Sticker, appreciate the confirmation that I’m not out in left field on the mix ratio.

I’ve been buying either the Tractor Supply 41 gly with surfactant already mixed in or the Rural King brand, also with the surfacant. Rural King had the 2.5 gallon jugs on sale for $30 last year, which to me seemed like a pretty good price. I probably should have bought more, maybe tractor supply will have a sale.

Grouse

$30 for 2.5 gallons is a steel!!! If you see that price again PLEASE let me know. I usually get it from my fertilizer guy for $35-40 for 2.5 gallons but this year it went up to $43 for 2.5 gallons.

Randy, with that ratio and strength of spraying do you only need to hit it once a year, or do you still have to go back for a second application later in the year?

Related question:
Are the suggestions for using 2-4 oz/per gallon on weeds only or can I use that same application rate for spraying my RR beans and corn?

First time I’ve planted them and never sprayed them.
I was planning on using 3 quarts in 50 Gallons of water. Covering about 2-3 acres.

also, I think I need to wait until the corn is about 8 inches high.

Am I in the ballpark or missing the plate completely??

Oh by the way, last year I asked about planting beans/corn with a grain drill.
I put dividers between openings and blocked off a couple. Corn is about 30″ apart and the beans are in-between corn rows. It’s a little spotty in places where I dug up virgin(weedy) ground but for a food plot…it worked good.

Yes, 2 oz per gallon is what I spray my RR corn and beans with. No need to wait for the corn to get 8″ tall. Spray when the weeds are 2-4″ tall. You are not going to hurt the corn or bean plants no matter how small they are. But the sooner you hit the weeds the easier they are to kill/control

I only spray once. The first couple years was so-so results because of the huge abundance of weed seed in the ground. Now that I’m a few years into this on these plots, no significant issues with weeds.

Keep in mind that round up and equivalent products are applicable for maturing plants. Generally, the seed isn’t affected and won’t be killed until exposure after it has germinated. If I can find my old pics from I killed off these plots I’ll post them

sticker wrote:

$30 for 2.5 gallons is a steel!!! If you see that price again PLEASE let me know. I usually get it from my fertilizer guy for $35-40 for 2.5 gallons but this year it went up to $43 for 2.5 gallons.

Keeping in mind with Rural King, there’s shipping as well. So it’s about the same as you’re paying or maybe a little less as there’s no tax.

But that was still significantly cheaper than I could get 1 gallon jugs for at TSC or other places, so it was a relative good deal to me.

Grouse

I just checked Rural king for 41% gly and it’s $35 for 2.5 gallons or $47 with shipping. I am going to order 2 of the 2.5 gallon jugs for a total of $86.30. Thanks for the tip on Rural King Grouse!! The cheapest I can find it around here is $60 for 2.5 gallons.

sticker wrote:

I just checked Rural king for 41% gly and it’s $35 for 2.5 gallons or $47 with shipping. I am going to order 2 of the 2.5 gallon jugs for a total of $86.30. Thanks for the tip on Rural King Grouse!! The cheapest I can find it around here is $60 for 2.5 gallons.

Yes they have good prices if you order enough to justify the shipping costs. They have some good sales on stuff if you watch the site.

Grouse

I just looked at the Rural King site. What is the name of the stuff your are ordering? Can it be sprayed the same day you plant and not mess with the seed? I can’t get up there to spray before I will need to plant.
James

here is the link. Yes you can spray the day you plant, it won’t hurt the seed, just kills stuff that is green. But if you disturb the stuff you sprayed it could knock the spray off and make it less effective.

gly

Just ordered the 2.5 gallon jug of Gly and having it shipped to my buddies up by Roseau. The plan is to have him spray before I get up there. Right now I’m scheduled to go up over the 4th of July weekend to plant. Can I spray a second time when I plant my seed? I will have to move some dirt so weeds could grow back.
DT

Gly will only kill green stuff and has no residual affect. It is basically sterile once it hits dirt. If the weeds aren’t growing to spray again would be a waste of time and money. If I understand correctly you want to disc or till, then plant, then spray gly?

Most of the plot just has to be sprayed and drug and it will be ready. There is a new plot that will need to be turned over. I just didn’t know if it would help to spray after we ran the disc over it.
DT

OK, no don’t spray after you disc. You will just be wasting the chemical. If you get a good kill with the first spray before you turn the dirt you should be alright. You will get some new weeds from the seed you expose but the majority of weeds will be killed all the way to the roots so they wont regrow.