More than 500 kilograms of carrots, 500 kilograms of sweet potatoes - and some apples, will be donated to Hunter Wildlife Rescue to help feed kangaroos, possums, wombats and flying foxes.

The organic produce is a welcomed delight for the animal group because it has a longer shelf life in the bush.

Organic Feast owner Brent Fairns opened his wallet to buy the sweet potato and the apples after he heard most of the food sources had been decimated by fire. He dipped into the business's climate change strike fund to pay for the carrots.

Mr Fairns has challenged his customers - and the city, to help keep the donations flowing while the food sources in the bush remain scarce.

He has urged people to buy the food in his store - at cost price, so it can be given to the rescue group.

He hopes the community will continue to do this until the animals are out of strife.

"We've bought half a tonne of organic gold sweet potato. We're also making it possible for people to come in-store and see our staff and buy organic sweet potato and carrots that we can pass on, on their behalf, as well," Mr Fairns said.

"It's a devastating situation ... The diversity of life that has been lost ... This, in some small way, will help those that have survived to feel a bit better. Thank you in advance for your help."

Organic Feast general manager Sue Ferguson said it was a small gesture that would make a big difference and help preserve several animal species.

"Initially it was about helping the kangaroos and then Brent learnt that the flying foxes don't have any food either, and they eat fruit, so we are giving some apples as well," Ms Ferguson said.

Hunter Wildlife Rescue will store the food in a container and distribute it through several drops.