If you follow (or want to follow) my fertilization schedule, I’m suggesting a minor change for this fall, and I hope it will have a major impact in preventing weeds for the next 4-6 months.
I’m adjusting the pre-emergent herbicide application for autumn, and would like you to “double-up.” More precisely, I would like you to do a treatment immediately, and then do a second one in 60 days, so we get two treatments down before the end of November.
Why? Because of September’s wet weather and the deluge we got courtesy of Hurricane Harvey last year.
You might object because directions on most bags caution against applying more than “x times a year.” That’s usually good advice … we should avoid over-application of herbicides. But, this is a once-every-few-years situation, and a double dose will provide great protection, as long as you time them right!
You may be wondering why I didn’t suggest this last year, immediately following Harvey. Actually, I did. But not very forcefully. And I never put it writing. Instead, I focused more on soil remediation than weed prevention last September and October. Blocking weed seeds seemed trivial at the time.
If you already have a bunch of weeds in your lawn, remember that right now I’m talking about pre-emergent herbicides … to block weed seeds from germinating. When you already have weeds up, you need a post-emergent herbicide, like those I discussed for Virginia buttonweed, doveweed and basketgrass in my Aug. 30 article.
Speaking of Virginia buttonweed, plus nutgrass/sedges, no pre-emergent herbicides will block those nasty invaders. You should get to know my 10 rules of herbicides and become a herbicide-usage expert immediately.
So, to wrap things up, I don't care where you are with the fertilization schedule – get an application of pre-emergent herbicide down immediately. Then, mark your calendar 60 days out with a reminder to get a second one down.
Important note: Previously, I recommended some products that separately targeted broadleaf and grassy weeds, but they are simply too hard to find these days. So currently, whenever I refer to pre-emergent herbicides, I’m always talking about two-in-one products with formulations that include Dimension®, pendimethlin and Barricade®. With two-in-one products so prevalent, there’s really no need to seek out weed-specific brands anymore, so my fertilization schedule has been updated to reflect that.