Weed killers are a type of herbicide (a substance that is toxic to plants).
They can be great for wiping out weeds, but there are real questions about whether they’re safe to use, both for gardeners and the environment.
They could harm your other plants
Okay, they’re potentially harmful to plants, isn’t that the point? Not exactly.
You need weed killers for weed control, but they can also harm the plants you’re trying to help. If you’re not precise with your aim, you could cause carnage.
Part of the challenge is picking the right weed killer for your situation. Application methods for weed killers vary from one option to the next.
Contact herbicides only affect the part of the plant they come into contact with, while systemic herbicides move through the plant's system, even affecting the structure beneath the ground.
You need to understand the type of weed killer you're using – and its active ingredients – to make sure you're positively impacting your garden, not causing harm.
Going into detail, Philip says "There are different kinds of weed killers; some are contact and work as soon as they touch plant material, others systemic, absorbed by the weed and killing it as it spreads through the plant’s transport systems.
"If removing by hand isn’t possible and you resort to weed killers, always ensure you’re using them per the manufacturer’s instructions.”
They’re potentially hazardous to wildlife
Your outdoor spaces aren’t just filled with plants, but insects, birds, and other animals as well.
The wildlife in your garden could be affected by weed killers, if you're not careful. One recent study suggested a decline in British songbirds is partly down to the use of these substances.
If you have pets, it’s best to keep them off any areas you’ve treated with weed killer. Wait somewhere between 24 and 48 hours before letting them loose.
Some weed killers are advertised as ‘pet safe’ but, even in those cases, it’s better to be safe than sorry.
They might present health risks
There are mixed opinions when it comes to personal health risks posed by weed killers.
The main health risk spoken about relates to glyphosate, one of the common ingredients found in weed killers. The World Health Organisation (WHO) has said there’s a significant chance that glyphosate is carcinogenic (meaning it causes cancer).
Remember, though, the scientific community doesn't totally agree on this. It's just worth keeping in mind that using certain weed killers might mean taking a chance.
They can pollute the environment
Some weed killers, especially those containing substances like glyphosate, can contribute to environmental pollution.
There's a chance they'll affect soil health, non-target plants, and even contaminate water bodies as a result of runoff. This could mean they end up harming aquatic life.
Certain weed killers contain less harmful active ingredients and are positioned as environmentally friendly, but there are still debates around the effects they have on the environment.
They have a big carbon footprint
Let's put aside how weed killers affect your garden for a second. How do they affect the wider world?
The production and use of chemical weed killers contribute to carbon emissions, so they have a fairly significant carbon footprint.
Manufacturing processes typically require a lot of energy, which is more often than not derived from fossil fuels. This leads to the release of greenhouse gases.
Transporting these products from their manufacturing facilities to stores and warehouses further adds to their carbon footprint.