EPA north branch director Gary Davey said the authority was conducting a comprehensive investigation and had inspected the site.

“It is believed that the incident may involve a phenoxy herbicide (such as 2,4-D) and the EPA will be looking into this,” Mr Davey said.

Unfortunately it is not the first time this particular garden has been struck.

John Jackson said it was first hit in 2009 and after replacing a number of plants the garden was again wiped out by chemical last year.

This included 80 roses of particular sentimental value to Mr Jackson.

“Those roses were planted for my late wife and I’s 40th wedding anniversary. It was a memorial to her, and now it’s just wrecked.”

Mr Jackson and his wife, Maureen, started the garden from a bare block in 1978 and continued to work on it, even until now, to get it to the stage it is.

The garden has been a private oasis for the Jacksons, and has even been opened for public events.

“It’s just so depressing,” Mr Jackson said.

“I replaced roses last year that have just sat and done nothing because of the chemical in the soil. The trees are getting it too and carrying the chemical down to the root and into the soil.

“Everyone told me to plant alternatives, so I did, and now they’ve been hit too.

“The garden at this stage should be powering along, not hard to look after.

“It just shouldn’t happen,” Mr Jackson said.

“Obviously someone is not doing their homework and not spraying in the right conditions.

“It’s near impossible to tell where it’s coming from because it could be drifting for miles,” he said.

Mr Davey said it was critical that users of agricultural herbicides were aware of their responsibilities and ensured their actions didn’t impact on others.

“It is a legal requirement to always read herbicide container labels carefully and follow all directions,” he said.

“Phenoxy herbicides can spread for many kilometres if sprayed in unsuitable conditions. “Many plants are highly sensitive to phenoxy herbicides and the Australian Pesticides and Veterinary Medicines Authority has placed a ‘no-spray window’ on the high volatility 2,4-D esters between September 1 and April 30.”

Mr Davey urged people to carefully consider weather conditions before spraying. 

“If you are uncertain, then spray at another time when conditions are right. This will protect the local community and the environment.”

The EPA encourages people to report alleged pesticide misuse to the them on the Environment Line on 131 555. People making a report should advise of what they see, smell or hear and note the time and weather conditions, if possible. These details will assist with any investigations.