The Free State family killed on their farm near Lindley will be buried on Thursday in the town, the Volksblad newspaper reported.
The Potgieter family, from the farm Tweefontein, would be buried in one grave.
Attie Potgieter, his wife Wilna and their three-year-old daughter Willemien were murdered on their farm a week ago. Potgieter was stabbed, while his wife and daughter were shot.
Potgieter's father Andre said the families decided to bury the couple and their daughter together because they died together.
A memorial service would be held at the Lindley NG church for the family, the report said. The funeral would be at the Lindley cemetery.
Regional Free State agriculture representative Johan van Tonder said the families had asked that no organised event by political parties or other groups be held during the funeral.
“To them it's a private event and they want to greet their children in peace,” Van Tonder was quoted saying in the report. - Sapa