The mysterious Macedon Oak

A few years ago, I was asked whether I knew about the Macedon oak. ‘Well, of course’ I said, making a mental note to look it up later.

I have to admit, I am still yet to see a living specimen of this famed oak (hence the few images in this post). This illustration from the logo of the famed Mount Macedon & District Horticultural Society was all I knew of the oak before I 'looked it up'. I soon discovered that Quercus ‘Macedon’ (a cultivar of unrecorded species called ‘Macedon’), with barely lobed leaves, was, at least in part, a pin oak (featured in my last post). 

That connection can be traced back a place called Firth Park, a large home garden near Tylden, about 18 km to the west of Mount Macedon, in central Victoria. The park was established by a Joe Firth and has since been converted into a picnic and camping area at the edge of what is now Wombat State Forest. Which explains an alternative name for this cultivar, Quercus ‘Firthii’. 

Firth was a forester and an arborist, but also a professional gardener at two properties in the town of Mount Macedon – Glencairn and Government Cottage – and then later Superintendent of the Macedon Forest Nursery. The first mention of what is also known as the Macedon oak, are from plantings in Firth’s old garden near Tylden, and in those two gardens at Mount Macedon. 

Learned authorities consider ‘Macedon’, and ‘Firthii’, to be variants of, or a hybrid with, pin oak. Which make sense when you look at the cut of the leaves, and their ‘armpits’. There may be more than one variant, or hybrid, with a tree labelled ‘Quercus firthii’ (not a formally described species name) from the Macedon Forest Nursery with firmer leaves of possibly different origin to those now growing at Firth Park. 

In the more usual form, the leaves are variable in shape, even on the same tree, often with 'hairy armpits'. More often, the leaves are narrower than those on your typical pin oak, less deeply divided and persisting long into winter – sometimes right through the year some say. The acorns are at the smaller end of pin oak scale, described in our HortFlora as ‘almost level with the top of the cup’. But as with us hybrids, little is consistent among our siblings and some specimens have more fulsome fruits. 

As to the second parent of the Macedon oak, you would expect it to be an evergreen species of some kind, but no-one seems to know. A few are willing to speculate but as usual, things just get curiouser and curiouser. One of the largest specimens alive today, at more than 19 m high, grows in a beautiful garden called Cruden Farm, in Langwarrin. 

It’s been suggested the Cruden Farm tree came from a Mount Macedon property owned by William Baillieu, called Sefton, and that it was grown from an acorn collected from a natural crossing of a willow oak (Quercus phellos - not one of my favourite oaks) with a northern red oak (Quercus rubra). 

Willow oak, as species I don't like (Central Victoria, December 2022)

Now, both those species are fully deciduous and not known for their hairy armpits, so either the Cruden Farm tree has nothing to do with the oaks bred by Firth or its purported pedigree is incorrect.  

Although, when I finally got to see some leaves from an authentic Macedon oak - in this pressed specimen held in the National Herbarium of Victoria - I can see that they are not unlike what I'd expect a cross between a willow and northern red oak to look like.  

But not so easy. In 2004, Allen Coombes, an oak expert from Hampshire County Council in the UK no less, examined pressed specimens labelled Quercus ‘Macedon’. You can see a copy of his emailed response next to the specimen above. Coombes reckons the more typical form might be a pure Chisos oak (Quercus graciliformis) from Texas and Mexico – of which there seems no other record in the botanic garden – and the tougher leaved form, either Bartram's oak (Quercus ×heterophylla) or Schoch oak (Quercus ×schochiana), two formally named hybrids between pin oak and willow oak.  

Chisos oak is reliably deciduous and as far as I know, with leaves hairless beneath. The two hybrids would likely have some hairs but are equally deciduous. Whatever their origins, Coombes considered them quite different entities, and was surprised they were being grown under the same name in Australia. 

Given all the uncertainty, we may as well keep calling anything a little odd from Mount Macedon, with a hint of pin oak, a Macedon Oak.