Weeds and "The Law of Instrument"
Glyphosate has been our hammer, and it's time we opened the toolbox and choose the right tools to look after our surfaces.
Glyphosate - The golden Hammer
According to the law of the instrument, when we acquire a new skill, we tend to see opportunities to use it everywhere. This bias is also known as “the law of the hammer”, “the golden hammer”, or “Maslow’s hammer”, in reference to psychologist Abraham Maslow’s famous quote: “I suppose it is tempting, if the only tool you have is a hammer, to treat everything as if it were a nail”
As an industry we have been guilty of seeing glyphosate as a "Golden Hammer" and every weed as if it were a nail.
The problem is, weeds are normally a symptom of a surface issue, not the core issue themselves. Glyphosate is a useful tool for killing weeds. I'm not trying to argue with that, but it doesn't solve the underlying causes of the weeds or the issues they lead to, so the surface is left to deteriorate and under perform.
The image below shows the typical result of not maintaining the kerb edge of a road.
(Picture credit - an interesting blog from a resident in Abingdon https://abingdonblog.co.uk/?p=20715)
Before we jump for the hammer (Glyphosate) I'd like to first identify the causes of the problem and why it needs to be solved.
What is the cause of the weeds along the kerb edge?
Weeds are growing along the kerb edge because the kerb stones are forming a trap for detritus. When organic material is blown across the road from surrounding vegetation the Kerb acts as a trap and collects all the material.
Over the course of a few weeks and months this detritus breaks down into soil, becoming a nutrient rich seed bed for weeds. It does not take long for a substantial accumulation of soil to occur if it is simply left to its own devices.
What happens when we only spray the weeds?
When we spray the weeds with glyphosate, or other similar products, it kills the weed, but the weed does not disappear. Instead it decomposes and adds to the build up of soil. This gets rid of the weeds for now, but does not address and actually adds to the underlying problem... The soil.
Why is the soil along a kerb edge an issue?
The kerb edge performs several functions.
- It acts as a channel for water to run down to a drain... when soil blocks the kerb edge it prevents the water running to the drain and can also block the drain leading to flooding on the road after heavy rain.
- If the tyre of a slow moving vehicle glances the kerb, it will usually redirect the car back onto the road. If soil is in the gap it acts like a ramp, allowing the car to more easily mount the kerb, which is dangerous to pedestrians using the pavement.
If we kill the weed, but we don't remove the weed and the soil then we are not solving anything other than a visual problem.
The functions of the kerb edge are still greatly impeded.
What could we do to solve the problem?
Instead of diving for the knapsack, we can remove the detritus. This can be done at any stage, but requires different tools depending on the state of the material.
- Before the organic material breaks down and becomes soil...
When detritus is in its early stages of decomposition it is usually very easy to collect using a sweeper or vacuum. Sweeping the kerb edge is a quick, cheap and easy method of preventing weeds occurring, keeping the channels free for water to flow to drains and preventing soil from ramping the kerbs.
- After the organic material breaks down and becomes soil...
When the soil has built up it is no longer an easy operation to handle with a sweeper or vacuum. After this point the soil must be removed by heavier tools, either by hand using shovels, or much faster and more economically on a large scale with machinery such as a weed brush.
Kersten sweepers and weed brushes are great at maintaining hard surfaces by removing detritus and debris which reduces weed growth and is fundamental to Integrated weed management.
For much more information on weed prevention please take a look at our new Weed Prevention Guide for the Amenity Sector
You should also check out our 4 step plan to phase out glyphosate.
More information on Kersten Weed Brushes can be found on the Mechanical Weed Removal Page.