A public family fun day will be held, with a tree planting, treasure hunts and stories in the forest, kite making and decorating, bonsai demonstrations, guided forest tours and terrarium workshops.

Face painting, jumping castles and live music are sure to keep children busy, as well as appealing to the young at heart.

The chairwoman of Friends of the National Arboretum, Jocelyn Plovits, said the 4000 members have worked to ensure the community can take full advantage of this fantastic place.

“I feel very proud,” she said.

“As a group we have done an enormous amount for the Arboretum – but to develop the friends a well.”

More than 200 guides have been trained through the Friends of the National Arboretum.

Volunteers help with working bees, and have made significant inroads in science by closely measuring the vast range of unique species as they grow.

The enthusiasm of members watching the new forests establish has been palpable, but Ms Plovits said one of the most fulfilling aspects of her work has been watching how the space has captured the imaginations, particularly of younger generations.

“We love having children involved because some of these trees live for 1000 years. That is 36 generations,” she said.

“While this group of friends is enormously keen and dedicated, we are also keen to bring in the new generations as they come along.

"It's kind of vital,” she said.

Chief Minister Katy Gallagher said the success of the National Arboretum had exceeded all expectations, with more than 500,000 visitors coming to enjoy the site in the first year.

“This first birthday party will be a great chance for people, including those who haven't visited the Arboretum as yet, to celebrate the milestone and partake in a range of fun activities in correlation with the Canberra Day long weekend,” Ms Gallagher said.

Seed from the National Arboretum provides a reserve of biodiverse plants, used for research and to assist communities across Australia and abroad to replace plant species after natural disaster or destruction.

“It's of world significance. An arboretum has that capacity to make a contribution, preserve biodiversity for use in the world not only in the ACT, which is magical,” she said.

“It was started with those goals in mind of research and education but also a community space. You can just come with a picnic if that is what you want to do, you don't have to be a mad botanist.”

After the huge first year working to establish members and support the space, Ms Plovits said she has noticed how the arboretum has captured the imagination of those that come to visit.

The first year has brought great ideas such as the Warm Trees yarn bombing of trees last winter, an initiative that is planned again for 2014.

“The ideas keep coming and fortunately we have a growing membership to implement these great ideas,” she said.

“Ideas like that reach out and bring different groups from the community, sometimes those who don't necessarily get involved with trees into the Arboretum.”

The fun day is not ticketed, but spaces for the three tree planting sessions held at 10am, noon and 2pm are limited so please book early by contacting the Arboretum on 6207 8484.