The National Botanic Garden of Wales has appointed Mark Kerr as interim director with immediate effect replacing Kevin Lamb, who left suddenly after three years in the post last month.
Kerr is from a Royal Navy and local-government background. He said: "It is a really wonderful and exciting place. My first task is to get to know the Garden and all the staff and volunteers here - I'm looking forward to the job immensely."
Chair of trustees Rob Jolliffe said: "He is a first-rate operator, a good leader and excellent manager - and we are all looking forward to working with him.
"Part of his role in the coming months will be to help trustees find a permanent successor."
From 2004 to 2009, Kerr was chief executive of Powys County Council, responsible for 12,000 staff. Before that he was director general of Human Resources (Royal Navy) in the rank of rear admiral.