They bought land, made a wetland and now Whanganui's Sisters of St Joseph of the Sacred Heart want to plant the steep hillside below their Mount St Joseph.
The hill is "what's holding it all up", Sister Noelene Landrigan said. It suffered slips in the June 2015 heavy rain and sheep can no longer be grazed on it.
The sisters applied to national body Trees That Count for a donation of up to 300 native trees to help hold on to the soil. There were more than 1000 applications and theirs was one of seven lucky ones.
The trees arrive next month, and Sr Noelene is organising a planting day for August 30, starting at 9am. Anyone who wants to help can ring Mount St Joseph on weekdays and register with Karen Erueti, ph 345 5047.
The Sisters used to own a little farm on the edge of St John's Hill. They kept the land at the top, and their Mount St Joseph base and Nazareth Rest Home and Hospital are built on it.