New Contact Herbicide Trials

There has been more than the usual number of questions about what I am calling "bio-based" herbicides recently. Arguably, this is coming from news that some school districts and cities specifically calling out the use of glyphosate on the properties they manage.  Landscaping departments want to know which of the products available work the best.

To start, please be aware that all of these products are contact herbicides that will not move through the plant. Therefore, they will not be effective if you are trying to get to any underground organ such as the roots, rhizomes, tubers, etc. of any perennial plant. Do not try to make a head to head comparison to glyphosate - glyphosate will win every time.  These act more like diquat (Reward) so if you are using Reward, some of these could be a good replacement, if needed.

 Here's what I have in:

*listed as “organic” but not necessarily OMRI certified

**listed as a biopesticide

 I also tried A.D.I.O.S. (active ingredient:  sodium chloride + other ingredients: potassium chloride, sodium bicarbonate) in a preliminary experiment and found that it was a waste of my time.

 The rates for most of these can be quite high. For example, WeedPharm is applied with no dilution even though it carries a “Danger” signal word on the label. Other are applied at 3-25% rates by volume.