To Jimmy Turner, the living botanical treasures of Sydney's Royal Botanic Gardens and Centennial Parklands are more valuable than the Mona Lisa and black rhinos, and more important to the world's future.

"Wherever there is nature there is hope," tweeted Mr Turner, the director of the garden's horticultural management. Reflecting on the bushfires and destruction, he urged the public to choose to be part of the solution rather than cast blame. "Nature is telling us something. I intend to listen and change accordingly. Will you join me?" he asked, using the hashtag, #PlantsNotPolitics.

Mark Holdcroft and his son Luca on drought affected Busbys Pond at Centennial Park in Sydney. Credit:Isabella Porras

At Mt Tomah Botanic Gardens, one-quarter of its main garden's 28 hectares were affected by bushfire. Fires also damaged its 186-hectare conservation area. With infrastructure damaged, it was closed and is scheduled to reopen next week.

Mr Turner said the impact of the drought had been dramatic and obvious on green spaces, and was likely to cause damage for years.