Miscanthus Weed Control

[Spiider]

Before planting my staggered rows of M x G this spring, I had sprayed the lane early with Gly, tilled it up a couple weeks later and planted them. Then right after planting I put down some Atrazine and Gly. That worked great for about 1.5 months but now the weeds are coming on strong. Even though the MxG is anywhere from 3-5' now, I'm wondering if I just let it go for this year, then control the CSG's again next spring? Or if I should try something else to control weeds all summer and into fall?

And on that topic, I've read 2, 4-D also works as a post-emergent. Should I treat these areas any different in the 2nd growing year?

 

[*Hawaii5joe*]

Would tree mats work miscanthus? I might give them a wirl. I've got hundreds laying around from a bulk order 4 years ago.

 

[Spiider]

Would tree mats work miscanthus? I might give them a wirl. I've got hundreds laying around from a bulk order 4 years ago.

Good thought but no, the rhizomes that are planted spread from year to year. So this year I've got 1-3 stalks per rhizome growing, next year should be around 7, and the 3rd year around 25!

 

[Bill]

I had the same thing going on. I applied 2-4 db. Same as 2-4 d but it won't kill clover or alfalfa and hit it with more Atrazine. Don't know the results yet. The dosage per acre limits on atrazine are so you won't put down enough to hurt next years crop. I figured since I wasn't having a next years crop a little extra wouldn't hurt.

My problem is going to be volunteer sorghum which may be atrazine resistant.

 

[Spiider]

I had the same thing going on. I applied 2-4 db. Same as 2-4 d but it won't kill clover or alfalfa and hit it with more Atrazine. Don't know the results yet. The dosage per acre limits on atrazine are so you won't put down enough to hurt next years crop. I figured since I wasn't having a next years crop a little extra wouldn't hurt.

So you've used both 2,4-db and Atrazine? Just want to be sure. I guess my worry about applying either one is that it's too late in the growth of the MxG, or that I'll hurt/kill it at this point. Or should that not worry me? My rows of MxG are on the outside edge of my Egyptian Wheat/Sorghum screening.

I also downloaded the document from here for reference:
http://sustainability.uiowa.edu/ass...s-information/Mxg-weed-control-ISU-PM3055.pdf

 

[Bill]

In early June I sprayed the combination of atrazine and 2-4 db diectly on and around second year plants. It had no effect on the emerged Miscanthus. 2 weeks ago I sprayed the same combination on first year plants. 4 days later some of the weeds were curling with no change in the miscanthus. I'll be heading back next Wednesday and will be able to let you know if that is still the case.

Based on what I have read it is atrazine resistant so atrazine should not affect it. 2-4 d or 2-4 db will not hurt it as this is a broad leaf herbicide that won't harm any grasses.

Over spray on your sorghum may pose a problem to it. I say may because it is safe pre emergent on sorghum that has been treated. Most seed is treated.

Egyptian wheat ? I don't know anything about it other than it is a type of sorghum. I've never used it.

 

[Spiider]

In early June I sprayed the combination of atrazine and 2-4 db diectly on and around second year plants. It had no effect on the emerged Miscanthus. 2 weeks ago I sprayed the same combination on first year plants. 4 days later some of the weeds were curling with no change in the miscanthus. I'll be heading back next Wednesday and will be able to let you know if that is still the case.

Based on what I have read it is atrazine resistant so atrazine should not affect it. 2-4 d or 2-4 db will not hurt it as this is a broad leaf herbicide that won't harm any grasses.

Over spray on your sorghum may pose a problem to it. I say may because it is safe pre emergent on sorghum that has been treated. Most seed is treated.

Egyptian wheat ? I don't know anything about it other than it is a type of sorghum. I've never used it.

That sounds very promising, I'm going to try it. Now, for hopefully the last question... I don't see any rates/acre on the information books that came with the atrazine or 2,4-db that talk about Miscanthus... What mixture/acre did you use?

 

[Bill]

That sounds very promising, I'm going to try it. Now, for hopefully the last question... I don't see any rates/acre on the information books that came with the atrazine or 2,4-db that talk about Miscanthus... What mixture/acre did you use?

I used what the label recommended for corn. But there was some guess work on my end as its hard to calculate for a hand sprayer. I'm sure I was a bit heavy, no water ways near by so I didn't see a problem with run off.

 

[Bill]

Also, and I could be wrong, I think I remember the label saying not to mix atrazine with 2-4 db. To be safe you could spray them separately a few days apart.

I mixed them.

 

[Bill]

Sorry I'm slow this morning. I used the rates recommended for alfalfa on the 2-4 db.

2-4 D won't have that recommendation.
Not really sure other than to say go with what it says for your lawn.

Also be careful with the crop oil / sufficant. That might burn the Miscanthus. I used very little.

Replace it with a few drops of dawn dish washing soap if you want to play it safe. The dish soap will help as a sticking agent.

 

[Spiider]

Gotcha, thanks for all the info. Yeah, I think I'll start with the 2,4-DB (I was mistaken when I omitted the "B" initially) since it's pretty much broad leaves I'm after. And good point on the Surf, I'll try the Dawn alternative with this, I'd rather play it really safe with these. And same here, I'll be using a 4 gallon backpack sprayer for this application, which is going to be maybe 300' long by 4' wide total sprayed area, which will make calculating that out tough for me. Thankfully I've got a former mechanical engineer and MIT graduate for a wife who can figure it out for me :)

 

[homegrownbucks]

I am gonna try some oust, atrazine helps but always seems to end up weedy by the end of summer. I have a planted 1500 plugs and rhizomes and very little of it looks good. The stuff with weed control looks better than stuff without, but I think something to really keep the competition away will help. I don't know if I have seen anyone use oust but it works for switch so I will assume it works for GM, but I am not gonna do a huge area in case it doesn't.

 

[Bill]

I am gonna try some oust, atrazine helps but always seems to end up weedy by the end of summer. I have a planted 1500 plugs and rhizomes and very little of it looks good. The stuff with weed control looks better than stuff without, but I think something to really keep the competition away will help. I don't know if I have seen anyone use oust but it works for switch so I will assume it works for GM, but I am not gonna do a huge area in case it doesn't.

I'd try just a few first. Hate to see you loose them all. Let us know if it works. If it works it would be a good way to prepare a site the fall before planting.

 

[klee7013]

gonna keep a eye on this thread. Got two strips of MG and the one i sprayed looks decent the other one. pretty rough. full of weeds

 

[OakSeeds]

Attached are photos showing why weed/grass control is so important to the development of hearty Miscanthus plants. The first photos show how a little grass can stunt a plant ... in the photo the plant 4th from the right should be as large as the plant 2nd from the right ... the 2nd photo shows the relatively small amount of grass that caused the problem. In photo 3, you will see a nice Miscanthus Gracillimus plant in 2013; and the harmful effects of competition in 2014. Finally, I will share 2 photos of Miscanthus Varigatius ... before and after flopping.
With my editing, the last photo shows the two Miscanthus Gracillimus plants about the same size last year; now the one on the right (it is on the left in the stunted photo) is much smaller than the one on the left because of some grass (see base of single plant in photo 2 / left to right - top row).

P.S. Notice the large amount of wood mulch; I believe these plants must be protected from competition on a regular basis if we want them to thrive.

 

[dipper]

Any updates on the oust? I've got over 40 cuttings in the ground that I harvested from my parent plants. I've got them tight up to quack grass, with roots already surrounding them. It would be nice to cut those nasty quack roots off.
Just like most of you guys starting a my screen, I want to start as close to the edge I can. Due to having A good screen of sorghum Sudan going. I'm only working with an acre, so I need to save every inch I can get at this point.

 

[Dbltree]

1
Oust XP kills most grasses, the only reason (I believe ) it doesn't kill NWSG is because the root's go so deep. It will kill seedlings however which leads me to believe that Oust will kill miscanthus because their root's are shallow, or at least appear to be.
I was always going to test it but never got around to it, I hope I am wrong because Oust provides excellent grass control ;)

 

[OakSeeds]

Miscanthus in full bloom; beautiful rust colored flowers.

 

[Spiider]

Just thought I'd bring this to the front as some will be planting these, and others cleaning up a little for 2nd year plantings.

 

[Bill]

Yep, I'm to late for gly/atrazine so I plan on hitting them with the atrazine/2-4 D when I get back.