Anyone use Grass b Gon?

10 years ago

I'd like to know if anyone has experience with using Ortho Grass-B-Gon around your bearded iris. I don't want to damage the iris, but this grass that grows naturally on the hillsides around here is crazy bad!

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davidrt28 (zone 7)

10 years ago

Actually, the chemistry of Poaceae (grasses) IS different from other monocots. That's why Trimec can kill onions quite well in a fescue lawn, without killing fescue. Even though both are monocots. (just did it myself, to a slew of onions. I have so few now I just spot treat rather than use my broadcast sprayer)

At least one over-the-top does list Iris as an acceptable background plant. That being said, I would still be *very* cautious. I have sometimes sprayed with Triclopyr around various monocots like Daffs, Irids and Yuccas to control things like violets. Generally, it has been fine as long as you minimize the amt. of spray hitting the foliage. However, I saw some delayed minor injury on some Gladiolus papilio some time later for which I cannot rule out the herbicide. (OTOH, could have just been a response to drought or changeable weather, which we got a lot of in the summer) The oddest thing is there's a whole paper somewhere from a southern university saying that triclopyr will control the hideous native Smilax vine. But that hasn't been my experience at all, even using plenty of surfactant. (which is the only way to get roundup to kill it) But even though Triclopyr minimally affects most monocots, it supposedly suppresses bermuda grass in a fescue lawn, although I'm a bit skeptical of that.

Here is a link that might be useful: http://www.garden.com/ContentFiles/Associated_Content/OrnamecOTT-SL%5B1%5D.pdf

This post was edited by davidrt28 on Sat, Apr 26, 14 at 14:23

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Comments (9)

sandyslopes z5 n. UT
Original Author
10 years ago
No one? All right, if I try it I'll let you know.
gardengal48 (PNW Z8/9)
10 years ago
I doubt you will get very happy results :-( Iris are monocotyledons, just as are grasses and herbicides - with the exception of the nonspecific, broad spectrum potions like RoundUP - target either the monocots OR the dicots. Herbicides can't tell the difference between what we consider a weed or a valuable plant. Their only ability to differentiate is based on plant type - broadleaved plants (dicotyledons) or grassy, blade type plants (monocotyledons). Grass -B-Gone targets monocots.......and that would include iris.
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jmcdmd
10 years ago
I've heard of something called "Over The Top". It comes up on Google.

I remember seeing or hearing that that can be used directly 'over the top' of iris plants.

Please don't take my word for it. Do research.... But it seems I heard of it on "Victory Garden" or maybe in this forum.....It's been a few years back..

I'm getting back into iris again (was frustrated by all of the weeds, grasses, etc.) so I need to give this OTT a try myself.
davidrt28 (zone 7)
10 years ago
Another very strong example of that is Sedgehammer/Halosulferon-methyl. I had weedy sedges growing right in the middle of some Fargesia 'Green Screen' divisions. There would have been no mechanical way to get them out without destroying the divisions. Sedgehammer completely killed the sedges (monocots) without bothering the bamboo at all.

This post was edited by davidrt28 on Sat, Apr 26, 14 at 14:25
sandyslopes z5 n. UT
Original Author
10 years ago
Gardengal and David, thanks for your replies. I appreciate the logical approach and admit I don't know much about these chemicals. You're both talking over my head a bit, but I'm always glad to learn new things when it comes to my plants and gardens. I have anxiety over using any herbicides, but I'm that overwhelmed with grass to consider this.

The label on Grass b Gon lists "iris" as being safe to use around, and I was hoping someone might have tried it already. I sprayed some of my variegated iris the other day, so we'll see how that goes.

jmc, thanks for the suggestion of Over the Top. I've never heard of that one before, and I did find it on google. I haven't noticed it in any stores near me, but now that I know there's another option, I'll keep an eye out. I wonder if either one of them is considered safer than the other when it comes to birds, insects, and nature in general.

I know there are iris lovers who are cringing at the thought of an herbicide near any iris. So I want to let you know that I did successfully free one patch of bearded iris from catnip, motherwort, and lemon balm. I do my best to weed it out by hand, it's just that this grass....ugh!
harryshoe zone6 eastern Pennsylvania
10 years ago
I have used it the last two years with some success.

I'm not even sure which weedy grass I am treating. Maybe Bermuda grass? Its got long runners beneath the soil which are impossible to pull out. The coarse grass is visible in March and can be sprayed before desired plants have leafed out.

It takes a few weeks, but the grass eventually fades away.
sandyslopes z5 n. UT
Original Author
10 years ago
Thanks, harryshoe! That's what I wanted to know. The grass grows underneath and in every little crevice, so that's why I'm resorting to this method. Glad to hear it hasn't hurt your iris. I just sprayed so haven't seen any results yet. "grass eventually fades away." ....That is music to my ears!
ginnier
10 years ago
I used it but don't really have a comment on how well it did...It was such an odd summer, but I THINK it worked on the edges of my flower beds.
My comment really is about how it evaporates out of the container! So then I wonder about the concentration of the remaining product! I had a brand new bottle and it lost at least a third into the air of my garage!! The first bottle was really down too, anybody else have this issue??
I know my garage is hot, but yikes!