Last year's Waimarino challenge in Raetihi attracted 59 entrants who produced 80 dishes, and Mr Manson said adult competitors need to watch their backs.
"The winning entry was only one point ahead of the top children's entry last time, and kids have been doing well in other New Zealand challenges as well."
As a cook who enjoys the outdoors, Mr Manson said he came up with the concept in 2008 and held the first challenge in his home community of Eastbourne, Wellington.
The concept caught on and Mr Manson, his wife Sarah and their daughter Grace, 11, now travel New Zealand and the world promoting wild food challenges.
There are five regular challenges happening in New Zealand and the family live part of the year in North America promoting challenges in Finland, Italy, France and the United States.
"I have just come from Whakatane where they have held their first challenge and they were inspired by the Waimarino challenge. The council and the iwi really got behind it, and it was a fantastic event."
The venue for this year's Waimarino challenge is the Raetihi Cosmopolitan Club, and Mr Manson said the carpark would be dressed up for the occasion.
"Bill has a really good template for every challenge, and it is up to me to find talent to enhance this one and give it local flavour," said Steve Gray. "We will have live music from local musicians and we have a guy doing ta moko tattoos."
Mr Gray said he has a few other ideas up his sleeve but is waiting for confirmation before he announces them.
"It created such a buzz around town last time, so I'm sure it will be great this year."
Mr Manson said anyone could enter the challenge and it was a great way for people to realise how many natural resources they had at hand. "Even if you live in the middle of town in New Zealand, you don't have to go far to find food sources. People have made some really good drinks that have won challenges - dandelions are a great ingredient, and you can find those growing in cracks on the footpath," Mr Manson said.
The Local Wild Food Challenge is open to everyone. Competitors can register online by going to the website localwildfoodchallenge.com/waimarino-nz