They started fostering children for Child, Youth and Family 34 years ago, even before they'd finished having a family of their own.
"We've both just got a passion for children so we thought that rather than just keeping on having children" Mrs Broderick said.
Most of the children are with them for only a short time until they go to a permanent home, but some stay for longer, including David Sullivan, 19, who came to them when a baby.
Mrs Broderick trained as a paediatric nurse, enabling her to provide the care required for babies with health issues.
The couple helped to establish social services organisation the Open Home Foundation in Wanganui in 1983 and Palmerston North in 1985.
They also set up a health clinic at Himatangi.