WHEN a large tree in their backyard started to look a little sick, Jennifer and Andrew Rendalls decided to take a closer look.

That's when they discovered it had been deliberately poisoned.

Mr Rendalls said they noticed the tree had started to change colour a while ago.

"It was pretty clear something was wrong, it's a big tree, you can see it when you drive down the street.

"It got worse, turning orange, starting to rot from the top, so we checked it out."

Mrs Rendalls said she spotted the axe marks and drill holes in the tree.

"That's when I realised someone had been in our yard, intent on killing this tree," she said.

"That really scared me, who would do a thing like that.

"I'm a stay-at-home mum, I'm here most of the time, looking after my one-year-old."

Mr Rendalls said the whole incident was frustrating.

"It means someone...has had an issue and done this rather than approach us about it in a civil manner," he said.

"If someone had a problem, they could have said or written us a note.

"But instead they've taken things to an invasive and potentially dangerous level."

The poisoned tree has started to lean dangerously and an arborist friend of the Rendalls not only confirmed the tree had been poisoned but also informed the couple the tree would need to be removed sooner rather than later.

"He told us that it's not safe to climb so we'll have to pay for a cherry picker I think," Mr Rendalls said.

"Until then, we have two small children to watch out for and a dying tree aiming to fall towards our house.

"What if the kids had touched or eaten that poison.

"We've spoken to police, but there isn't a lot we can do without proof or evidence.

"We're just going to be a lot more vigilant and keep our eyes open from now on in."