How to tell if weed killer has been used?

Else

A neighbour's weeds (incl. Crofton Weed & Morning Glory) are spreading, growing at height & encroaching on my garden. They're too high to reach on my side so I asked them to do sthg about it. The weeds thrived there for years but suddenly they started to wither & go brown. Now they're completely dead.

Our neighbours have said that nothing has been done but the way the weeds look suggests otherwise. My concern is that if they've been sprayed it was done from high above & there's a strong risk of aerial drift on to our property. We also don't know what was used or when.

1. What is the best way to tell if weed killer has been used?
2. Are there any laws that are supposed to apply in this kind of situation?

Thank you! 😊

MitchellMc

Hi @Else,

It is very difficult to tell with certainty whether weed killer has been used, because many different things can cause weeds like Crofton Weed or Morning Glory to suddenly brown off, including weather, disease, mechanical damage or even root disturbance. Herbicide damage usually shows up as wilting, browning and die‑off over a period of days to weeks, but those same symptoms can also happen naturally, so there is no reliable way for me to confirm whether they were sprayed.

Regarding rules, you might like to reach out to your local council to see if they can provide some insight.

At this point, the only definite thing is that the weeds have died back after growing strongly for years, and whether that’s due to herbicide or a natural decline is not something that can be determined from appearance alone. If you are worried about possible drift affecting anything on your side, keep an eye on your own plants for any sudden wilting or spotting.

Please let me know if you have any questions.

Mitchell