July 18th, 2025Beetham Botanicals

Well, here I am penning another article for you, the reader, to enjoy…
This time I’ll be commenting on predicted climate change and what it means to those working in horticulture, landscaping, garden design and to the home gardener. The plants we’ll be looking at will be trees.
So let’s start with figures that were sourced from an app that was put together by various institutes including the Royal Botanic Gardens Melbourne and the Botanic Gardens Conservation International, supplying a wealth of information on trees that culminated in the climate assessment tool that I am using now.
The current mean annual temperature for Daylesford is 11.3 degrees Celsius, the projected mean for 2050 is 13.1 and for 2090 15.3 which amounts to an increase of an average 4.0 degrees over 65 years. It doesn’t sound a lot but these figures would make Daylesford’s future weather akin to a range of areas around the world including here in Australia from Parkes (New South Wales) to Toowoomba (Queensland), South-Central China and parts of Mexico. Scary hey, and by the way, Hepburn’s mean annual temperatures were consistently just 0.5 degrees warmer than Daylesford.
So how will this affect our choice of trees to plant? Well, for starters our range of trees available is dependent on current nursery stock and a lot of these trees have been tried and tested in the past and are now guaranteed best sellers.
At this point I think I’ll mention Climate Resilience which is to say that some trees will naturally adapt to increasing temperatures. This has already happened in the past with many species existing well outside their native climatic conditions – those that instantly spring to mind include many araucaria spp. such as A. bidwillii (bunya pine) from Queensland, A. cunninghamii (hoop pine) from New South Sales, Queensland and New Guinea, and A. heterophylla (Norfolk Island pine), magnolia grandiflora (southern magnolia) from the warmer parts of southern USA and sequoiadendron giganteum (giant redwood) from higher altitudes of the Sierra Nevada in California.
Of all those above only the giant redwood may struggle with forecast temperature increase. I am currently acting as a consultant to the Kyneton Botanic Gardens to research what tree species would be suitable for future plantings in the gardens and so I can tell you there are many fine trees that would make themselves at home here in Daylesford/Hepburn including eucalypts from southwestern WA, native rainforest species from around Toowoomba (figs and tulipwood – harpullia pendula), oaks and pines from Mexico, conifers and maples from South-Central China, drought and frost specimens from Capetown to Zimbabwe, camellia spp. from warmer parts of China to northern Vietnam and rhododendron ssp. from the Himalayas.
Of course it’s all very well to speak of such wondrous new trees from our own Aussie backyard and exotic parts of the world, but how will we source them? I guess it will come down to empowering the nursery trade to offer more of these suggested tree species for us to try in our gardens and so in the meantime consider choosing tree species that, as they mature, have a better chance of coping with warmer climes.
I thought to finish off I’d give you three climate-resilient tree species (see images) that I consider to be fine future additions to any landscape, garden design or the home garden: hymenosporum flavum (native frangipani) from far-eastern New South Wales into far-eastern Queensland and onto New Guinea, pinus patula (weeping Mexican pine) widespread throughout Mexico and Buckinghamia celsissima (ivory curl) from north-eastern Queensland.

Cheers John Beetham (Trees in Australia)
Scan the QR code to JB’s Instagram post
Next time: the wonderful world of bark, flowers & foliage…