Water Hemp

[andersont@maccray.k12.mn.]

I tried spraying about an acre of old cattle pasture to plant switchgrass for additional bedding cover. Water hemp took over the area and none of the switch grew. If I let this area go will other briars, broadleaf, trees and some of the switchgrass eventually break through or am I stuck with an acre of water hemp unless I spray or mow this area?. Thanks!

 

[Bill]

Need more info. When did you spray? When did you plant the switch? Where are you located? The water hemp may be glyphosate resistant. You may need to time a good spraying of liberty (Glufosinate) or a pre emergent like atrazine.

You may just need to wait. Switch grass is a slow grow plant. It may take up to 3 years to shine.

Tell us more.

 

[andersont@maccray.k12.mn.]

I sprayed roundup on an area that was predominately smooth brome grass and thistle in early Spring and that area got dominated by the Water Hemp. I am located in Eastern South Dakota. I'm thinking of mowing the area in the spring and trying to re broadcast the switchgrass seed.

 

[Skeeter]

If you felt good about your seed coverage and didn't spray after the seed germinated, I'd just mow in mid June or early July this year.
I broadcast my switch in a drought year and thought I had a complete failure. The switch came in great two years later in the areas that I hadn't sprayed and just mowed after I thought it had all failed.

 

[Bill]

Also if it's just broadleaf weeds "water hemp" you could spray 2-4' D Amine. It won't kill grasses.

 

[Brian662]

Pre emergent spray this spring - simazine or atrazine. Then spot spray as needed with a broadleaf killer- 2,4-D or dicamba and/or mow it the first year.
Second year the switch will outpace the broadleaf pressure.

Only way switch usually fails is to be completely shaded by a broadleaf or killed with herbicide.