- Author: Cheryl A. Wilen
A colleague recently asked me what I thought about the Iron HEDTA (FeHEDTA) herbicides that recently came on the market. I replied with, "Uh..." Turns out that she is located in northern California and I'm in southern California and I guess the iron train has not arrived down here yet because no one has asked me about it. So I decided to check it out.
I could only find a little information online where the product was tested and it was not really a planned study, more like a what I call a squirt and look experiment. Generally that's not a good sign. If something works, there are usually a lot of scientific reports about it because researchers want to see where it can best be used. Nevertheless, I wanted to try it myself so I went looking for a bottle at my local nurseries. I say nurseries because I had to go to a few to find even one product that contained Iron HEDTA. I found WHITNEY FARMS LAWN WEED KILLER although there are 4 other registered products with the same active ingredient.
Concentrate - BAYER ADVANCED NATRIA LAWN WEED CONTROL CONCENTRATE 26.5%
Concentrate - FIESTA TURF WEED KILLER 26.5%
Concentrate - IRON-X SELECTIVE WEED KILLER FOR LAWNS 26.5%
Ready to use - ORTHO ELEMENTALS LAWN WEED KILLER 1.5%
Ready to use - WHITNEY FARMS LAWN WEED KILLER 1.5%
Long story short, this stuff works. I tried it on broadleaf plantain, dandelion, woodsorrel oxalis, and black medic in a tall fescue lawn. It took about 1 week for broadleaf plantain to die and the black medic was not controlled at all. However, the oxalis and dandelion both were showing injury in 1 day and were controlled in about 3 days. There was no turf injury.
I do want to caution you that there is no soil residual although there may be some longer term postemergence activity (I hesitate to speculate that it is systemic). The area I sprayed for oxalis had new plants about 3 weeks after I did the treatment.
I'll put a longer report with photos in the next Green Bulletin (http://ipm.ucdavis.edu/greenbulletin/index.html) or Retail Nursery and Garden Center IPM Newsletter (http://ipm.ucdavis.edu/RETAIL/retail-newsletter.html)