Boxes of ripe mangoes from a north Queensland farm have arrived in the city ahead of Thursday's Slow Food Earth Market.

And they are here for a very special reason - to help Bruce and Helen Hill who are small farmers in Townsville.

There is a real problem with mangoes in Townsville - they all ripen around the same time, and that has left the Hill's with a real dilemma.

Should they leave the fruit on the trees and let it ultimately become fertiliser, or, try to sell them elsewhere?

They tried to sell them locally but nobody wanted them - even though they are biodynamic.

Enter Slow Food Hunter Valley and a food rescue plan was hatched.

"There was no point picking their 70 trees because they were too small, compared with other ones, and nobody wanted them," Slow Food Earth Market Maitland chairwoman Amorelle Dempster said.

Read more: Make it your mission - munch on a mango

Read more: 10 things you can do with mango

"The crop isn't big enough to send to an agent, and the supermarkets don't want them because they aren't all the same size.

"That's Maitland's gain. Our community is amazing and has strongly supported this cause before. We hope they will come out to the market and do it again.

"I've seen the mangoes on the truck and they are a beautiful size, they have ripened on the way down."

The fruit will be sold at the Slow Food Earth Market Maitland from 12.30pm on December 5. They are $2.50 each or $25 for a box.

This is the third consecutive year that Slow Food Hunter Valley has brought mangoes to the earth market for shoppers to enjoy.