August 2, 2011
Here is the second installment of the July 7 post on Nimblewill control in lawns. This demonstration is being conducted by Richard Jauron, the answer line person in the horticulture department. He is using tenacity (mesotrione) to try to completely eliminate Nimblewill from his home lawn. We're going to follow this and see if Richard or the Nimblewill wins the final battle. It may take a two years before we know. The answer line number is 515-294-3108.
The nimblewill was initially treated on Tuesday, June 28, 2011. One-fourth teaspoon of Tenacity and three-fourths teaspoon of a non-ionic surfactant (Turbo Spreader Sticker) was added to 2 quarts of water. Nimblewill infested areas were spot-treated with the solution. Within 2 or 3 days, the nimblewill foliage turned light green. Within 7 to 10 days, the uppermost growth turned white. At the end of 3 weeks (see attached photos), the lowest portions of nimblewill were still green. Most of the upper portions of the nimblewill were white or brown. The nimblewill was treated a second time on Tuesday, July 26. One-fourth teaspoon of Tenacity and three-fourths teaspoon of a non-ionic surfactant was added to 2 quarts of water.
As of August 2, the nimblewill has turned white. We know that it can come back, however, and that it can germinate from seed in the soil in the spring. Richard will be persistent with his applications in the fall and spring. We will keep you informed of what is happening.