Invasive plant - Ask Extension
This plant appeared 6 weeks ago in my front yard and is spreading. Want to get rid of it. How do I treat to get rid of it?
Knowledgebase
Invasive plant #878257
Asked July 22, 2024, 1:03 PM EDT
This plant appeared 6 weeks ago in my front yard and is spreading. Want to get rid of it. How do I treat to get rid of it?
Montgomery County Maryland
Expert Response
Hi,
Unfortunately your photo is too small for us to see clearly enough. Can you try to resend them at a larger file size? We need photos to be at least 1MB so we can zoom in on them.
Regardless of what it is though your options are either to hand pull/dig or to use a systemic herbicide to kill it. A non-selective systemic like glyphosate or triclopyr will kill the turf grass around it. To use a selective herbicide it would be better to know what the weed is, so the photos will help us.
Emily
Hello. Same pics in higher resolution i hope this helps. Thank You.
On Monday, July 22, 2024 at 02:31:52 PM EDT, Ask Extension <<personal data hidden>> wrote:
Thank you for the larger photos. This is a grass (our initial first impression was a sedge), though it's hard to tell which species as fine structural details that we can't see here are used to separate grass species. (Examples include ligule, vernation, sheath, collar, and root structure, examples of which can be viewed in a grassy weedy ID publication by Ohio State.) Flowers and seed heads also help to narrow-down and confirm ID for grasses, though we would not recommend allowing this weed to get that far in development so it doesn't spread further from seed.
In your photos, the off-center midvein to the leaf, the reddening of the leaf tips, and the aggressive spread suggest Cogongrass, also known as Japanese Bloodgrass (Imperata cylindrica). If so, it is an invasive perennial species. We're not certain from the photos alone, though, so you may need to use a magnifying glass and make comparisons to the ID traits of this species mentioned in the link above. Virginia Tech has an online grassy weed ID key as well that might be useful, which encompasses many grass species found in Maryland as well, though for some reason Cogongrass isn't in that database. Alabama Extension also has a web page listing ID features and makes comparisons to several other similar-looking native and non-native grass species.
Whether this is indeed Cogongrass or not, any perennial weedy grass will need either physical removal (digging it out, making sure to get all spreading roots) or spot-treatment with a non-selective systemic herbicide. One of the most common systemic ingredients is glyphosate, which is one of only two ingredients known to affect Cogongrass (though it's fine for other weedy grass species as well). More than one application may be needed to be fully effective, and follow label directions regarding any interval to wait between applications. (Likely once in fall, and again in spring.) Such sprays are going to damage any other vegetation they contact, so spray carefully and use a shield like disposable cardboard to keep a spray from drifting onto any nearby desirable plants like other perennials or shrubs.
Since Montgomery County has lawn pesticide regulations, we don't know if Cogongrass, being a federally listed noxious weed (not on the state noxious weed list), would be exempt and permitted to be treated with a synthetic herbicide like glyphosate. You may need to inquire with county government for clarification, as the website doesn't indicate that.
Miri
In your photos, the off-center midvein to the leaf, the reddening of the leaf tips, and the aggressive spread suggest Cogongrass, also known as Japanese Bloodgrass (Imperata cylindrica). If so, it is an invasive perennial species. We're not certain from the photos alone, though, so you may need to use a magnifying glass and make comparisons to the ID traits of this species mentioned in the link above. Virginia Tech has an online grassy weed ID key as well that might be useful, which encompasses many grass species found in Maryland as well, though for some reason Cogongrass isn't in that database. Alabama Extension also has a web page listing ID features and makes comparisons to several other similar-looking native and non-native grass species.
Whether this is indeed Cogongrass or not, any perennial weedy grass will need either physical removal (digging it out, making sure to get all spreading roots) or spot-treatment with a non-selective systemic herbicide. One of the most common systemic ingredients is glyphosate, which is one of only two ingredients known to affect Cogongrass (though it's fine for other weedy grass species as well). More than one application may be needed to be fully effective, and follow label directions regarding any interval to wait between applications. (Likely once in fall, and again in spring.) Such sprays are going to damage any other vegetation they contact, so spray carefully and use a shield like disposable cardboard to keep a spray from drifting onto any nearby desirable plants like other perennials or shrubs.
Since Montgomery County has lawn pesticide regulations, we don't know if Cogongrass, being a federally listed noxious weed (not on the state noxious weed list), would be exempt and permitted to be treated with a synthetic herbicide like glyphosate. You may need to inquire with county government for clarification, as the website doesn't indicate that.
Miri
