Medicine Man
Member
Roundup ( glyphosate ) is safe to use at the base of the trees to kill emerged, green weeds and grass. If you want to extend the length of control you can tank mix it with a number of pre-emergent herbicides. If you can find Surflan( oryzalin) that will do a decent job of preveting weed seed germination. Avoid hitting the green bark of any small tree because you can sometimes injure the tree if it is a young tree with chlorophyll in the tissue.....you can always shield the bark of young trees to prevent spray contact.... Fill your backpack sprayer about 1/2 to 2/3rds. with water....add 2 oz. of Surflan per gallon of water and then 3 oz. of Rounduo per gallon of water to the tank.....pump back in after filling tank full and you are ready to spray.
Can use any of these & I use several depending on situation. Also, I am NOT including Oust here because it is not safe on shrubs & fruit trees.
Atrazine (my go to with others mixed & you do need others, especially if there's lots of residue/trash on top)
Simizine (similar to atrazine, not as effective but don't need RUP)
Surflan like above,
Prowl (big fan)
Warrant/Dual or Mechlachlor
Plateau/Panoramic (used for native grasses and certain forbs but excellent for tree sprayings).
I'm a little nuts & have all these herbicides in my barn so I actually use all of them (I don't use Simizine because I have the Atrazine) BUT I usually will walk out with round-up or clethodim & crop oil (to kill grass, use one or other depending on timing) + Atrazine & then I add some plateau, prowl & Warrant. I easily could cut this down to Atrazine/prowl/plateau or Atrazine/warrant/surflan or a number of combos. I would not rely on just one though. Pigweed & waterhemp problems - I hit harder with prowl for example. But, it short, use 2-3 residuals, watch them and most likely it will be very effective.
No Round-up if trees are budded out. Yes if not. If trees are not dormant, use clethodim & crop oil to kill the grass. The above will keep you weed free when sprayed at high rates for a long time if done right. Get a good sprayer. Only back-pack sprayer I have had no problems with is the Stihl model. Sticky & thick chemicals will gum up cheap sprayers and ruin electric motor sprayers like my cheap fimco i have. I either use my Stihl backpack sprayer OR i use my 3 point sprayer on tractor with PTO pump with a good quality spray gun.
Happy Easter!
Atrazine (my go to with others mixed & you do need others, especially if there's lots of residue/trash on top)
Simizine (similar to atrazine, not as effective but don't need RUP)
Surflan like above,
Prowl (big fan)
Warrant/Dual or Mechlachlor
Plateau/Panoramic (used for native grasses and certain forbs but excellent for tree sprayings).
I'm a little nuts & have all these herbicides in my barn so I actually use all of them (I don't use Simizine because I have the Atrazine) BUT I usually will walk out with round-up or clethodim & crop oil (to kill grass, use one or other depending on timing) + Atrazine & then I add some plateau, prowl & Warrant. I easily could cut this down to Atrazine/prowl/plateau or Atrazine/warrant/surflan or a number of combos. I would not rely on just one though. Pigweed & waterhemp problems - I hit harder with prowl for example. But, it short, use 2-3 residuals, watch them and most likely it will be very effective.
No Round-up if trees are budded out. Yes if not. If trees are not dormant, use clethodim & crop oil to kill the grass. The above will keep you weed free when sprayed at high rates for a long time if done right. Get a good sprayer. Only back-pack sprayer I have had no problems with is the Stihl model. Sticky & thick chemicals will gum up cheap sprayers and ruin electric motor sprayers like my cheap fimco i have. I either use my Stihl backpack sprayer OR i use my 3 point sprayer on tractor with PTO pump with a good quality spray gun.
Happy Easter!
Last edited:
northcedar
Well-Known Member
Hey Sligh thanks for your info you share. I have a question about the Stihl sprayer. Are you using the brass cone tip that came with it, or have you found a replacement fan tip? I just got a SG71 and am wondering if I could be doing a better job of spraying around the shrubs with a different nozzle. I have seedlings in the ground, some are in spots where I had the sod killed from last fall, but others are in green sod where I'm hitting the plantings with atrazine, prowl, bean oil & cleth. At your recommendation on here a couple years ago, I filled in bare spots in a hardwood plantation with various shrubs.
EatSleepHunt
Active Member
I was wondering how effective clethodim & crop oil are on warm
Season grasses ? Big blue and Indian grass mostly. I have an area
Of a 3 year old tree planting I didn't get a kill on because of fall drought
conditions and the grasses went dormant earlier before I could get
a good kill before I planted in the spring. Thanks for any info.
Season grasses ? Big blue and Indian grass mostly. I have an area
Of a 3 year old tree planting I didn't get a kill on because of fall drought
conditions and the grasses went dormant earlier before I could get
a good kill before I planted in the spring. Thanks for any info.
Sorry on delay. New baby girl & Farm stuff eating up all my spare time. 
I still use the tip that came with it. Adjustable and I've not had problems BUT maybe I don't know what I'm missing?? I could have changed a nozzle a while ago and forgot though too, so, I guess I'm saying, dunno on that one, experiment and see which you like best.
WARM SEASON - you will kill those with NOTHING RIGHT NOW.... not round-up, not clethodim, not oust, nothing. You need to wait until the natives are up and growing quite well (yes, there's growth stages they are most vulnerable to kill but just wait until you have maybe 12" of growth for example and you'll kill em fine.). So, natives are likely still dormant now. I'm going to guess, depending on soil temperatures, you'll see growth in a month and 6-8 weeks you can do your spraying for example. You will 100% want to use clethodim & crop oil and I'd use them at high rates. Round-up is out of the question unless you're a precision expert on not getting any drift on trees (don't try it, just use clethodim & Crop oil). This will kill cool seasons and warm seasons.
if you're talking "IDEAL KILLING TIME" which we almost never can do things "perfect" - we all have to compromise..... Your best killing time on brome & Fescue & cool seasons is generally May 20th. Before reproduction of plant starts. On Warm seasons, generally a month or 6 weeks later. BUT - realistically..... especially if you're not covered solid in warm seasons.... I'd just spray it all around May 20-30th. It SHOULD get natives if you spray heavy enough. Like, I'd suggest 20-25 OZ or even 30 of Clethodim and then the crop oil & at least 2 residual herbicides, 3 would be better. What you will see if natives aren't all killed- you'll see some nice looking sparse Native clusters here and there BUT again, unless it's crazy thick native stand, it really isn't going to hurt anything having a small amount of natives that didn't die among your trees. Good luck!
I still use the tip that came with it. Adjustable and I've not had problems BUT maybe I don't know what I'm missing?? I could have changed a nozzle a while ago and forgot though too, so, I guess I'm saying, dunno on that one, experiment and see which you like best.
WARM SEASON - you will kill those with NOTHING RIGHT NOW.... not round-up, not clethodim, not oust, nothing. You need to wait until the natives are up and growing quite well (yes, there's growth stages they are most vulnerable to kill but just wait until you have maybe 12" of growth for example and you'll kill em fine.). So, natives are likely still dormant now. I'm going to guess, depending on soil temperatures, you'll see growth in a month and 6-8 weeks you can do your spraying for example. You will 100% want to use clethodim & crop oil and I'd use them at high rates. Round-up is out of the question unless you're a precision expert on not getting any drift on trees (don't try it, just use clethodim & Crop oil). This will kill cool seasons and warm seasons.
if you're talking "IDEAL KILLING TIME" which we almost never can do things "perfect" - we all have to compromise..... Your best killing time on brome & Fescue & cool seasons is generally May 20th. Before reproduction of plant starts. On Warm seasons, generally a month or 6 weeks later. BUT - realistically..... especially if you're not covered solid in warm seasons.... I'd just spray it all around May 20-30th. It SHOULD get natives if you spray heavy enough. Like, I'd suggest 20-25 OZ or even 30 of Clethodim and then the crop oil & at least 2 residual herbicides, 3 would be better. What you will see if natives aren't all killed- you'll see some nice looking sparse Native clusters here and there BUT again, unless it's crazy thick native stand, it really isn't going to hurt anything having a small amount of natives that didn't die among your trees. Good luck!