Gardner will referee the first Test at Nelspruit's Mbombela Stadium on August 6 while Pearce will referee the second at Ellis Park in Johannesburg a week later.
Twenty-seven-year old Nika Amashukeli from Georgia will referee the New Zealand-Argentina game in Christchurch on August 27 while Nic Berry, from Australia, will referee the second Test in Hamilton a week later.
The All Blacks Test against Australia at Melbourne on Thursday, September 15 will be refereed by Frenchman Mathieu Raynal, while the September 24 final New Zealand game in the Championship will be refereed by Irishman Andrew Brace at Eden Park.
New Zealand referee Paul Williams will have the Australia-South Africa game in Adelaide on August 27, with Ben O'Keefe as assistant referee and Brendon Pickerill as TMO.
O'Keefe will referee the second Australia-South Africa game at Allianz Stadium in Sydney a week later with Williams as assistant referee and Pickerill again on TMO duties.
James Doleman will referee the Argentina v South Africa game in Buenos Aires on September 17 with Chris Hart as TMO while Hart will fill the same role in the return game in Durban on September 24.