View Full Version : weeds laughing at my roundup

07-21-2002, 12:39 PM
im trying to clear an area, it contains honeysuckle, english ivy, myrtle, and assorted weeds. ive been using a roundup concentrate mixed at 2 oz per gal of water, im getting some browning on the leave tips, but for the most part the stuff looks it isnt dying. i did 2 apps in the last 3 weeks. can i use something else? need to give it more time? im not used to this method of killing things, i usually clear an area by hand before landscaping, but this is too much. thanks for advice.

07-22-2002, 01:01 AM
If it is hot and dry, the plants will not take in the Roundup properly I have discovered. The dry heat causes the plants to sort of go dormant. Also, I use 3 oz/gal. on tough weeds like you describe, and I add a few drops of liquid detergent to every gallon to act as a dispersing agent on plants that have shiny leaves. I usually give it 10 days to two weeks to kill the weeds before I give up and spray again. Hope this helps.:)

07-22-2002, 01:02 AM
good luck with this heat, it is tough to kill weeds when its hotter than 85

07-22-2002, 07:24 AM
Too bad ya live in Jerzee. Mayby you can just try the Pro Dry.


Round Up Pro Dry. + Scythe

71% glyphosate 1 - 1.5oz dry packet
4 oz liquid Scythe (not for sale in MA, NY, NJ, CT, VT, HI, AK)
1 gallon water

treats about 500 sq ft , QUICKLY.

07-22-2002, 10:03 AM
No weeds will roll over & die when the growth has slowed like it has. Earlier in the season is best to take advantage of active growth.

For the record: RoundUp is not the most stellar performer on woody brush to begin with. Roundup is also not a very fast herbicide. But that's why it works so well. It takes time for the Glyphosate molecules to translocate (move) throughout the vascular system of a plant. The slower a plant is growing, the longer this process takes. Under the best of conditions, Roundup still isn't "fast" by most peoples standards. No matter what surfactants Monsanto has added (to date) either.

I just recently treated such an area behind my neighbors garage. My motivation was security & the Poison Ivy oils that will eventually get on my "outdoor cat" & potentially give to my son.

Working for a manufacturer/distributor means I have access to a LOT of different products. All the same I used the following cocktail:

Round Up Pro Dry @ 1.5 oz/gal (2%)
(there were grasses in the over growth)

Scythe Nonselective @ 4 oz/gal
(helps break through waxy cuticles, death in hours or days, & improved summer performance. A classic "burn-down" contact herbicide. Lightning fast! Not a complete kill by itself though, more like a weed wacker than a herbicide since it doesn't translocate.)

LESCO 3-Way Ester 2 @ 1.5 oz/gal
(2,4-D does a great job on woodies that Roundup has trouble with. Lends permanence via conventional systemic activity)

To this cocktail I might have added Dimension Ultra or Surflan or Sarhara or some other residual herbicide if I didn't want anything to grow at all. Since it's late in the year, I decided that wasn't an important issue. Plus the guy behind my neighbor values the trees in the area which may have been damaged by the Sahara. You wou

I may still have to retreat this area for the Poison Ivy in the fall. I doubt I got all the roots. But you should see what it looks like right now! After the first week there wasn't a trace of green left back there! And it's in partial shade. Were it in the sun, the Scythe would have burned down the foliage by the following day, with visual symptoms starting before I had finished spraying.

Hope this helps,

07-22-2002, 10:10 AM
Bob, I think, but am not sure, that if you read the label you'll find you need a stronger solution than what you are using. I thought bottom end concentration was about a 2% solutionfor soft annual stuff and up to 10% for tough perennial, woody, viney stuff. Of course some newer versions of the product can have different specs.

Weather conditions as stated by others make a difference.

Timing can make a difference. Some tough stuff is better killed in late summer early fall while others are easy in the spring. Soft stuff can be killed at anytime.

I've personally used Lesco 3-way and Trimec with a sticker spreader in late summer to fall to kill anything I didn't like other than grasses. Knocks the life out of poison ivy, virginia creeeper etc. Use at maximum mix recommendation and spray till wet.

07-23-2002, 10:58 AM
Adding an equal amount of 24D to the RU will give you better burn. Remember, both of those are topkills. Lots of tough stuff will come back.

07-23-2002, 08:23 PM
Round Up & 2,4,d are systemics and not top kills. They go to the roots.

07-23-2002, 08:53 PM
Yes, and Santa Claus ate my milk and cookies last Christmas Eve.
And those are not the same perennial weeds I sprayed 2 weeks or a month ago.
they're both great for what they do, but don't give them more credit than they deserve.

07-23-2002, 10:46 PM
There are better products out their than round up pro or Lesco knock off of round up.

Myself, I use a part round up and turflon of esther to get rid of Ivy. And yes, it is a mutiple treatment. Sometimes I'll mix in some trimec(2 4 d ) to nail what I'm trying to kill wether it's Ivy, poison Ivy or Poison Oak.

Shawn Burns
07-29-2002, 09:44 PM
Wouldn't using Round-up and Scythe at the same time be counter productive? I have had this discussion with several other lco's and we haven't come up with a good answer yet, maybe you can help.
My thought is, that the contact burn of the Scythe will slow down the growth of the affected plant, thus slowing down or eliminating the translocation of the round-up. Also, if you back off the rate of the Scythe to allow translocation of the round-up, you will not get the desired "burn" on the plant, making it usless in the mix. Adding more Scythe to get the desired "burn" only makes the problem worse with translocation.
B.T.W., i have been told that the new round-up (don't remember the trade name) that advertises weed kill faster than before is just round-up with a shot of spectraside to give it the same "burn" that we are talking about.
Any thoughts would be appreciated.

07-29-2002, 10:14 PM
i never have particuarly liked scythe. when ued in backpack, or handheld sprayer, it needs constant agitation, to mix with the round up. if you are wearing a backpack sprayer, and some spills on you it tends to burn on your kin, specially in hot weather.

i only use scythe when weeds need to be given that burned dead look as fast as possible.

BTW, i think that 2oz per gallon roundup is too weak a mixture to be effective. at least in my experiences with it that is the case.

07-31-2002, 03:00 AM
we use round up dry and scythe and have had great success with this mixture, we however have only mixed it at a 2oz/gal rate. unlike the the 4oz/gal tremor perscribes . he however knows quite a bit more about this subject than we do, so he may be correct on the formulation. we havent had any problems as of yet..

07-31-2002, 08:59 AM
English ivy (thick, waxy cuticle)+hot weather (plants going dormant)+roundup (not as good on broadleaf as grass weeds) =
unsatisfactory results.

Mix in some 2,4-D with your 2oz./gal roundup

Make sure that you read the 2,4-D label in reference to hot weather applications, as some formulatiopns are more volatile and thus possibly hazardous to any desirable plants in close proximity to the weeds.

07-31-2002, 01:51 PM
I did use an ester based 2,4-D only for it's ability to penetrate the cuticle. Heat wasn't a big deal that day & the only ornamentals nearby that were worthy of consideration was Silver Maple roots which in this case, were not an issue.
High temps would require the use of Amine based 2,4-D formulas (regardless of maker) if there are ornamentals nearby that could be damaged by the volatile vapors.


I've had this same arguement with several colleagues myself. Everything about gylphosate tells me to do anything possible to encourage the salts to move as far as possible in the loger viney & woody plants. Everything about Scythe tells me that it should limit glyphosate movement. Yet that hasn't been the case on vines & brush in my customers experience or my own.

Another popular use of Roundup around here is erradicating Bentgrass & sometimes Zoysia for complete renovations. Since Bent has such long stolons (when cut at rotary heights) between the nodes, I never recommend adding anything to Roundup. Ive seen single app's of Roundup fail too completely erradicate the bents too many times. If anything, I advise the LOWEST rates for Bents. Then verticut, fertilize, & water like mad. Wait a few weeks for the previously unsprouted nodes to leaf up, then hit them with Roundup Pro at 3 oz. to make sure they're all gone prior to seeding.

So It seems that the targeted weed & the conditions present will help us decide on the proper approach. An eye on the longterm result is mandatory too.


John DiMartino
08-01-2002, 12:34 AM
Bobby, the plant isnt growing or taking in much,so it will be a slow kill.The only other thing i can think of is your water.The Ph plays a role to a point on the performance of the herbicide.I had trouble with roundup being ineffective once,it turned out the waters PH was 7.6,once i used different water with a ph of 7.1,the performance(and kill) improved.

08-02-2002, 09:18 PM

08-04-2002, 01:13 PM
Try Reward (A.I. Diquat) with 2%RU. Weeds die before you get the sprayer in the truck. Well---- almost that quick.