Switchgrass herbicide timing


Active Member
The clock is ticking! Here's my situation- I frost seeded about 18 acres of switchgrass from late January into late February. In mid April I contracted with the local ag supply to spray Atrazine and glyphosate on the plot. Well, rain and mud have kept them from doing the job, and now I'm starting to think it may not dry out for a couple of more weeks. I know LC said May 10th at the latest for glyph on newly seeded switch, but should I rely on soil temp readings more than calendar dates this year? We've had a lot of cool weather, and I'd really like to get a good gly burn on the chickweed and purple dead nettle. Is there a criteria I should use to tell me to cancel the gly in the mix?

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Another thought-since I've planted into corn stubble, there isn't really a problem with other grasses in the field. Perhaps I should swap out the gly for 24-D? If I do that, should I delay the spraying to give the switch a chance to start establishing?

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I don't worry on mine at least the first year to see how bad,i just keep mowed about a foot tall and then when it gets hot I usually quit mowing
That's an option, for sure. I have access to a tractor and bushhog. How many times did you end up mowing? I've heard guys say up to 6 times the first year.

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2-4D does have some residual effect. Personally I'd wait and spray it after the switchgrass has it's 4 leaves. We've had the same cooler, wetter than normal weather here in northern MO too. But to my surprise I found some germinated switchgrass on my planting this week.