Children will be positively encouraged to get their hands really dirty when they discover how easy it is to plant seeds and watch their own food grow.
The event is part of the National Trust's Food Glorious Food campaign, which aims to inspire children to plant, grow and eat their own local and seasonal food.
"We need a new generation of young people to connect with the land and grow food," said Iwan Huws, the National Trust's director for Wales.
"We know that once the children get started they will be hooked."
Seed planting and family fun will take place from 11 am to 3.30 pm and normal admission applies.
On May 27 and 28, families can forage with Colby's head gardener Steve Whitehead in his 'Wild Food Adventures', when he will be gathering the best of nature's food from the woodland garden, and cooking it over an open fire.
Steve will be leading two sessions each day at 12 noon and 2.30 pm (cost £2.50 per person, plus normal admission), and booking for this is essential, so call (01834) 811885 to reserve your place.