She said she plans to keep teaching in her role as senior fellow in music at the University of Waikato.
"It was time to seriously think about the singing."
"If you're a singer you have to train a lot, much like a tennis player, I do a lot of teaching and to be able to perform and teach is exhausting."
Dame Malvina has had a huge career in music with her first success at the 1963 New Zealand Mobil Song Quest, pipping Kiri Te Kanawa at the post.
She has received numerous awards, established a foundation to enable young performers to achieve their potential and trained Hayley Westenra.
Dame Malvina said she hadn't always planned to be an opera singer.
"I started singing at 2 years old but when I was about 12 or 13, I danced and I did a lot of singing.
"I really wanted to go to New York, to Broadway, to be a singer-dancer like Julie Andrews or Fred Astaire.
"But at the age of 17 my mother said 'this voice is too big'."
So opera was the path Dame Malvina took.
"Life has a way of simply leading you.
"There were some times where I thought 'what am I doing?' but opera has given me an incredible career."
She said she felt privileged to have toured the world.
"I've sung in some fantastic places around the world, from New Zealand to the pyramids of Egypt, Jerash in Jordan, the amphitheatre in Greece and the Grand Canyon."
And now she is looking forward to her North Island tour.
"The tour is going to be very interesting, the line-up is fantastic, the music will range from my early years and my later years."
Joining her on the stage will be founding member of Amici Forever, Geoff Sewell, the Hamilton County Bluegrass Band, the Hogsnort Rupert band and the RNZ Air Force and Navy Bands.
Dame Malvina said she hasn't been to Wairarapa often.
And she said she might have a wine after she's performed.
Early bird tickets to the tour's six outdoor shows are on sale now.