And, the Sustainability Unit at Muswellbrook Shire Council is looking for residents across the shire to be involved.

Council has always received great support from the Muswellbrook Girl Guides, Muswellbrook and Denman Scouts, Muscle Creek Landcare and locals for the annual events.

In 2019, they're expecting a similar response.

This year there are several locations across the shire where volunteers can get involved:

Sunday, July 28 - Muswellbrook - Karoola Park Dog Park, Semillon Street (9am to 11am)

Sunday, July 28 - Denman - Hyde Park, Babbington Street (9am to 11am)

Sunday, August 4 - Girl Guides Glenalla Campsite - New England Highway, Antienne (10am to 2pm)

The plantings will continue to re-establish local native species to improve biodiversity, increase shade, capture carbon and reduce weeds.

National Tree Day started in 1996 and since then more than four million people have planted 24 million trees and it's still growing.

It is an opportunity to do something positive for the local environment and community, allows people to reconnect with nature and inspires them to actively care for the unique land.

Council's sustainability officer Tracy Ward is particularly proud of the effort Muswellbrook and Denman residents put in.

"Muswellbrook Shire Council has participated in National Tree Day for more than 10 years," she said.

"In that time, we've planted in excess of 17,000 plants across Muswellbrook and Denman."

The Muswellbrook Girl Guides will also host an event on Sunday, August 4.

"The environment has always played a part in Guiding and, in return, Guiding has always advocated for and implemented good environmental practices in our community," said 2A Muswellbrook Guides' Sally Jackson said.

"We are looking forward to participating in National Tree Day events again this year."

There will be a free barbecue lunch; and volunteers are asked to wear long sleeves, shirts and pants, a hat, sunglasses, covered shoes and to bring a water bottle.

For more information, or to volunteer, contact the Sustainability Unit on 6549 3700 or email sustainability@muswellbrook.nsw.gov.au