"People feel better and more optimistic if they feel more connected with nature," she said.
"The whole aim of the week is to make people focus on their own and their family's and their friends wellbeing."
Ms Pentacost and another councillor Sheryl Smith will also be speaking at the Taradale Library at 2.30pm tomorrow.
More than 40 Staples Rodway employees were due to be locked out of their office building for an hour today for a picnic in Albert Square, however, weather meant that the event would be postponed until next Tuesday.
Employee and organiser Kerry Tattersall said the aim of the picnic was to promote wellbeing in the workplace, get out and enjoy nature and have fun with colleagues.
Wellbeing for any workplace was incredibly important for employees' mental health and their productivity, she said.
"We want to start to break the stigma that mental health isn't to be talked about.
"It's something that can affect anybody."
Mental Health Foundation chief executive Shaun Robinson said researched showed nature had positive effects on wellbeing.
"It makes us happier, decreases feelings of depression and anxiety, improves concentration, buffers against stress, makes our lives meaningful and reduces health inequalities related to poverty.
"There are lots of meaningful ways each of us can unlock our wellbeing by spending time with nature every day."
Today, which is World Mental Health Day, the Mental Health Foundation is holding a national lockout where everyone gets out of the office for an hour.
Central Hawke's Bay District Council is due to hold its own lockout at lunchtime today as well as Youth Horizons.
The Flaxmere Planning Committee, Hawke's Bay District Health Board (HBDHB) and other local services providers are hosting a 10 week wellbeing challenge with information on www.flaxmere.community.
HBDHB' Partnership Advisory Group for mental health will have a stand in the main entrance to the hospital this week and there is a walk tomorrow around Pandora Pond.