In my personal pond I have some sort of grass growing up among the marginal plants. The grass has sharp edges if you run your hand from blade bast to tip. Currently it is around 18" tall and will spread from stolons. No idea what species and I went to the Purdue Pond Seminar near Bass Lake last Sat and they had no idea what it was either. It has not started to set any seed heads.
Anyway, I am looking for a herbicide that will kill the grass and NOT the other marginal plants (Pickerelweed, Arrowhead, Blue Flag Iris and a few species of Sweet Flag).
I have not found a herbicide that is grass specific that is labeled OK to use around water.
So, does anyone have any suggestions? I cannot use glyphosate because the grass is growing among the marginals I want to save and is starting to shade them out. No way to separate the plants to just only spray the grass.
I called my chemical supplier and he was stumped but he was going to make some inquiries.
Phragmites I'm guessing is your problem . It is taking over down here in southern Indiana in most of the wetlands. All but impossible to control. You can kill it, but it is expensive and it will probably be back. I don't know of any chemical that will kill it and not you other plants that you want to keep. A Round Up and Imazapyr mixture will kill it. Alligare SL or Arsenal are a couple of brands that have imazapyr as the active ingredient and it is expensive, about 50-60 bucks a quart. Good luck I have fought this plant for years trying to keep it out of Peabody Coal mitigation streams and have had limited success.
What the heck??? I had wrote a reply yesterday and thought I had posted it. O.K., lets try this again.
I think it is a plant called "Cut Grass", either Zizaniopsis miliacea or Leersia hexandra but looking at the NRCS location map the Leersia hexandra is not supposed to grow here. I will have to grab a stem and bring it inside to match it with the description on the computer. There are no seed heads yet, so I can't go by that. Phragmites don't have sharp edges. Definately not Horsetail Rush nor Dwarf Umbrella Palm, I have Phragmites australis at a customers property and it's a pain to control too. I like to hit them earlier in the year to keep them from forming seed heads, and hit them again in the fall when they are taking a lot of nutrients back to the roots to store. I've found that by using a good surfactant helps get the herbicide into the plant. I don't like using Imazapyr due to it's propensity for whacking off target plants.
Like I said before, I'm not 100% sure whether it's Giant Cut Grass or Southern Cut Grass. I use Texas A&M Aquaplant frequently Aquaplant to ID plants, I don't know of another site that is like that. I recently heard that Purdue is supposed to be building one, and I have to check to see if it's on-line yet.
The one stand-out identifying feature is the "sharp edges" that feel like you are being cut if you run your hand from base to tip of the leaves, or walk thru it in shorts.
I know of 3 grass specific herbicides, but none are listed as being OK to use around water. 1 of them says "This product is toxic to aquatic organisms. For terrestrial uses, DO NOT apply directly to water or to areas where surface water is present or to intertidal areas below the mean high water mark", 1 says "Do not apply directly to water, or to areas where surface water is present, or to intertidal areas below the mean high water mark. Do not apply where runoff is likely to occur" and the last one says "is of relatively low toxicity to birds and mammals, but can be highly toxic to fish and aquatic invertebrates. Bluegill sunfish (96 hr LC50 = 0.53 mg/L) Fluazifop-p-butyl is not registered for use in aquatic systems.".
Look at the Arrest Max label. If the active ingredient is Sethoxydim, Clethodim or Flazifop then it can't be used where it can get into the water.