She had the support of MPs Nikki Kaye, Chris Bishop, Time Macindoe and Maggie Barry, who all stood alongside Adams during her press conference.
Adams believed she had strong support, but did not yet know if she had the numbers to win.
She mentioned her past, growing up in Auckland under a single mother, marrying a farmer and having two children, and spending 16 years as a lawyer. As a minister she has held 10 portfolios which she said demonstrated her intellectual rigour.
She said yesterday was the first day she had any discussions about the leadership, as she had begged English to stay on.
She said strong economic growth and strong fiscal management was at the heart of the party.
She said talk about the deputy leader was speculation and that Paula Bennett was doing a great job.
Unity was important and National had no intention of following the in-fighting that plagued Labour over its nine years in Opposition.
Adams said climate change was a critical issue and New Zealand had to play its part, but it shouldn't move too quickly to be economically crippling.
She added that when she was Environment Minister, she felt that cleaner, better water could be achieved, along with a strong farming sector.
She said she had a lot of respect for Judith Collins and Simon Bridges, but her unique blend of urban and rural experience, as well as family and commercial experience, made her the best candidate.
"I can be pretty tough when I need to be." But the focus was on winning the 2020 election. "Our focus is not going to be on the petty skirmishes along the way."
Asked about generational change, she said she came into Parliament in the same year as Simon Bridges and Jacinda Ardern, and change was more about a fresh perspective and keeping up with the mood of the public.
Asked about Judith Collins' experience in Opposition, which she has not experienced, she said: "We want to be the next Government, not the Opposition."
She said she was "aspirational" when asked for one word that summed her up.
She said she will be very upfront about what she thinks. "My integrity is something that means a tremendous amount to me. I don't believe in personal attacks. If you can't debate on the merits, you have a pretty poor argument."
"I wouldn't be standing if I didn't think I had the skills for the job."
• Simon Bridges and Judith Collins also declared their candidacy today.
• Steven Joyce and Mark Mitchell have said they are sounding out colleagues and considering standing.
• Paula Bennett has said she is not interested in the leadership, but would like to remain deputy leader.
• Nikki Kaye has ruled herself out of running for either leader or deputy leader.
• Dr Jonathan Coleman, who has put his hand up before for the leadership, said this morning he was not ruling anything in or out at this stage.