"When it's time to dig them up it's a bit like going on a treasure hunt. And the best bit is that we can wander around the garden eating all the yummy food."
There's not much that isn't grown in their grandmother's vegetable plot, and the sisters are also learning how to grow by the phases of the moon, a family tradition.
"We are still learning about how the moon affects the growing cycle of plants. Nana also teaches us about respecting Mother Nature, and gardening as naturally as possible," Tahlia, 8, said.
Nana Di said the girls were growing up with a genuine love for the garden and growing things.
"They are so passionate about gardening - even more than I was when I was their age, and being taught by my mother and grandfather. It is wonderful to see there is a lifetime of long-lasting joy in the garden for them ahead," she said.
Willow and Tahlia won a Yates hamper worth over $300 and are lining up alongside six other regional winners for the grand prize of a trip to Hawaii, becoming a Yates Ambassador for a year and spending time in their garden with a Yates horticulturist.
The grand winner will be announced during National Gardening Week – October 21-28.