By Jon Cooner
Q: When is the best time of the year to spray Arrest?
A: Arrest is designed to offer optimum control of “seedling” grasses. By that, I mean grasses that are growing vigorously, but that have not matured to the point that they’d be more than 6-12 inches tall if left un-mowed. Arrest can still control grasses that have matured beyond that point, but it may be more difficult, in some cases requiring that you use a higher concentration of Arrest in the spray solution, apply it more often, or both.
If that’s hard to figure out, here’s what I do. On my lease, I know that I will have to spray to control grass in my perennial plots. To gauge when it’s time to spray, I just watch my lawn. Often, it appears to
me once my lawn greens up each spring, it can be another week or two before it starts growing well. So, each spring I wait until my lawn greens up, and then I keep an eye on it. Once I see it starting to vigorously grow again, I know it’s time to go spray my perennials with Arrest.
I’m as guilty as others, though, in occasionally putting things off too long. Thankfully, controlling more mature grass with Arrest is still possible. It just requires a higher solution rate, and it may also require two applications a month apart.
Q: I am going to spray my Alfa-Rack Plus with Arrest to control grass. If I fertilize it first with 17-17-17, won’t that help the herbicide get into the grass faster?A: Not to the point that it will make a difference in the performance of Arrest (provided the spray solution is mixed and applied according to label directions). Instead, you should look at grass
control and fertilization as two separate steps in perennial maintenance, and you should perform them in order.
Do your grass control first. Your number-one priority when maintaining an Imperial perennial is grass control. That’s because Arrest is designed to offer the best control of grasses that are still in “seedling stage” (actively growing, but still so young that they could not have grown taller than 6- 12 inches if left un-mowed).
If you allow grass to mature before you try it, control is still possible with Arrest. However, it may require a higher mix rate, multiple applications or both, which costs you more. Adding nitrogen fertilizer to a stand of Alfa-Rack Plus also wastes money because it’s not necessary. And, it can cause you problems as well.
Alfa-Rack Plus doesn’t need nitrogen fertilizer for maintenance. The legumes in Alfa-Rack Plus are “nitrogen fixers.” That means they make enough nitrogen for their own needs, so your forage gains nothing by adding nitrogen fertilizer. That’s one reason we recommend that Alfa-Rack Plus be maintained with a zero-nitrogen (first number on the fertilizer bag) fertilizer such as 0-20-20.
In addition to wasting money, adding nitrogen fertilizer to a stand of Alfa-Rack Plus can boost the growth of grasses or weeds.
So, start your spring maintenance by controlling grass. Arrest is designed to control most kinds of grass, and it can be sprayed on any Imperial perennial. Check the Arrest label for a list of what grasses
Arrest will control and for full mixing and application instructions. If you have any questions about Arrest, call our consultants before you spray.
Q: The label on the Slay herbicide says that in my area, ammonium sulfate should be added to the spray solution. Ammonium sulfate has a lot of nitrogen in it, but your maintenance instructions for Imperial Whitetail Clover say to fertilize every year with a zero-nitrogen fertilizer (0-20-20). Won’t the ammonium sulfate boost weed and grass growth?
A: Not really. The Slay label says to include ammonium sulfate in the Slay solution when it is will be used in Texas, New Mexico, Oklahoma, or anywhere north of Interstate 40. Its purpose is mainly to buffer hard water in a spray solution, which can alter the herbicide’s active ingredients and reduce its effectiveness. Ammonium sulfate is 28 percent nitrogen, but it is used in such small volumes in the spray solution that very little nitrogen is actually supplied to the plants.
