Roundup: Should It Kill Poison Ivy?

mix 50 / 50 round up with poision ivy killer. that works fast and is 100% effective.

heck i kinda felt bad for the poision ivy.

the plant is actually attractive, if it wasnt for the itch:(

Same here. I use 50 / 50 glyophosphate with brush killer (usually 2,4D). Mix both to the highest concentration listed on the label. It still takes a week before the leaves start to curl and up to a month befor they go brown.

The Enlist system mixes 2,4-D and glyphosate. That's for fields where weeds could be resistant to either because both had been used extensively.

For poison ivy, I don't see the advantage of mixing. If after a week, I don't see results, I assume it didn't absorb enough. I spray again.

That didn't seem to work with some Spectracide 2,4-D stuff I got for buckhorn plantain. Seeing no results after a week, I'd spray again. There seemed to be fewer after I sprayed, but I didn't know why I never saw any shriveling or dead plants.

After a couple of years, I quit spraying and began cutting roots with a sort of forked bayonet. I had to bend over thousands of times, but it's fun when you get used to it, and it worked.

I haven't seen poison ivy resist repeated spraying.

Both are good brush killer and effect for your front yard. if you are interested to know more about the different check out the here:

Weeds like poison ivy laugh at roundup. It may knock the leaves off but it will be back. You are far better off with a Triclopyr based product, preferably mixed with a "sticker". Diesel works great. You don't need a lot. A little spritz will kill weeds like PI dead. It is what we use on Brazilian peppers, air potato and Ear leaf Acacia.

You sure have some weird s*it down there.

This is the sub tropics and our worst weeds are from the tropics. With a 12 month growing season things can get out of control very fast. Most of those little plants you see in a dish garden will just go nuts here if they get loose. The worst part is, like most exotics, someone brought them here as ornamental plants. The animals are usually escaped/released pets. (Pythons, Lion fish, Iguanas, Tegu)

Even roundup works a lot better on poison ivy if you add a bit of diesel as a surfactant

Roundup is still just a defoliant more than a systemic herbicide. That is why you can spray it on your dormant zoysia grass in the winter.

Diesel? Fuel?

Yup

A problem in discussing this is people just say Roundup without specifying what concentration. I mix it, generic, at 2% to kill common broadleaf weeds. If I have poison ivy, which is not frequently, I mix it 5%. And it has a surfactant. It works. But if you have a lot of it, then a brush killer product is more effective and surer. It's also temp dependent. When it's hot, Roundup works extremely well and fast. If it's 45f, not as effective and takes much longer.

Yup. It was the original recommended surfactant for Garlon 4. This is not something you are squirting out of an airplane. You just need to get some leaves with a few drops each and the plant will go belly up in a week or two and never come back. I typically treat an acre and a half with a 16 oz Zep bottle and have plenty left.

Good to know. I've been using industrial Roundup which works well but they always return awhile later. I end up just pulling the roots. I'll do the diesel this summer.

Thanks

On 2/14/2020 9:57 PM, snipped-for-privacy@aol.com wrote: ...

"Glyphosate is a broad-spectrum systemic herbicide and crop desiccant which acts by inhibiting the plant enzyme

The only reason it doesn't kill zoysia dead is that it's dormant at the time.

Similar issues with application at times is hot and dry and stuff isn't actively growing.

Like most other herbicides, against well-established wood brush it will undoubtedly take multiple applications or combinations to kill all the roots so it won't re-establish.

I have not used Roundup for a while, but have used other brands that have the same Glyphosate in them. They cost less for the same concentration and have other chemicals in them. Mainly something to help make it stick to the leaves. That is the only place on the plants that the glyphosate is absorbed. Poision ivy is slick and most sprays will just slide off. It usually gets rid of the poison ivy without any trouble if sprayed on during the growing cycle.

You can probably also spray it on cool season grass in the cold of winter and it won't kill the grass too, for the same reason, the chemical is not readily absorbed and transported. I know when I decided to kill my lawn and reseed, I got delayed and didn't apply the Roundup until Oct. Even though the temps were still moderate, I wasn't counting on how long it would take for it to kill it and for it go brown. I guess I probably could have just proceeded to reseed and the old grass wouldhave died, but I wasn't sure it would kill it. Instead of a week, it took maybe two and a half weeks for it to go brown.

Don't know why it should not work and I have killed poison ivy with all purpose broad leaf killers. I cleared up all the English ivy around my house a couple of years ago with glyphosate a couple of years ago. It did take a couple of applications.

I am sure that you have to spray the plants during some cycle of their growth depending on the chemical used.

Many people just buy something and put it out with out reading the directions and complain that it does not work. Like the preemergence weed and feed. It does no good after the seeds have sprouted and started growing. The feed part really feeds the weeds..

For some reason in the area I am in (central NC) many yards have been taken over by what many are calling chick weed. This has been a warm winter and lots of rain. I don't think we have had a full week where it has been below freezing which is unusual. Last week we were almost 70 deg F in the daytime. Seems like there has not been a full week with out rain.