- Author: Cheryl A. Wilen
The Healthy Schools Act was originally developed as a notification program to let students and adults who work or visit schools to know when pesticides were going to be applied. However, when the usage of pesticides was modified or decreased, schools found there was less exposure to people, especially kids, and the paperwork was also reduced. Enter an increased embrace of integrated pest management.
More recently, schools have been encouraged by concerned community groups to reduce the use of synthetic herbicides to maintain school grounds. One type of alternative is to use high temperature water with a foaming agent to act as a blanket to keep the heat on the plant longer. The other type is a machine that produces saturated steam. The California Department of Pesticide Regulation funded us to test the latter in place of herbicides.
There are a couple of things I need to point out before going further. First, this blog should not be considered an endorsement of any product mentioned below. Secondly, the reason we went with the saturated steam system is that the foam type machine was not widely available in the U.S. at the time we were developing the project.
We started treatments at a city park in Long Beach California at the end of July. This park was a good test site because it had most of the areas of concern that would be treated with a non-selective herbicide. This would be tree wells, edging, and near a playground.
We treated the sites 2 times, one week apart, initially and then retreated whenever weed cover was more than 30% (an arbitrary but practical threshold). Weeds at the site included annuals such as spotted spurge, goosegrass, and common knotweed and perennials kikuyugrass and bermudagrass.
So far, results have been promising but if you are looking for a drop-in replacement, you are not going to get that. However, if you are restricted to organic or similar contact herbicides or non-chemical methods this could be a money or labor saver in the long run if used in the right places. We used SW700, the smallest model from WeedTechnics.
The water input was from a hose bib but larger units should have 200-500gal tank.
Some initial observations after using it for about 6 months:
- A bit difficult to move around but long hoses help. Generally, need at least 2 people
- Can get a precise application but longer time to treat an area than herbicide
- 2-3 week retreatment
- No notification posting needed
- Can used when children are around
Edging along a playground
- Truck mount or trailer for larger units
- Price ~$11K-30K depending on model and accessories
Initial and after 2 treatments, 1 week apart