Killing fescue

[Hickory Hills 1]

I am planning to replace fescue on about 5 acres with some warm season grasses (big bluestem) . I plan to use Roundup to kill the fescue using a 40 gallon John Deere sprayer with an eight foot boom. Has anyone had any experience with this practice?

 

[MMagis]

Mow it first, give it at least a week (assuming it get's a little rain) to start growing back, then spray with a good heavy dose of gly. Would be a good idea to mix in some ammonium sulphate to help out. Mature, established fescue is tough to get 100% kill with one spraying, but you'll get close.

 

[sixdogs]

I'll say that adding some liquid detergent to the mix helps the spray break the "surface tension" and makes it stick to the grass better.
I added maybe a cup of Sam's Club pink dishwashing liquid ($5 ? per gallon) and it really seems to help.
As noted above, fresh growing grass kills better than older and stubble.