JARRAH
Jarrah (Eucalyptus marginata) is an iconic forest tree, famous for its fine timber qualities. With attractive reddish-brown stringybark and a full canopy of bright green foliage, a grove of old, undisturbed jarrah is a beautiful but rare sight. The Jarrah Forest is an Australia bioregion, originally some 50000 km². Remaining stands of old-growth forest is however, much less at around 2500 km² scattered widely over its former range. Jarrah also grow on the Swan Coastal Plain and the Warren region along with marri, for an original total area of around 72500 km² with giant trees scattered widely through out this range. Most old-growth jarrah remains in state forest unprotected from harvesting, and there are no national parks with extensive old-growth forest. Initial attempts 100 years ago to preserve areas as national parks were unsuccessful with the government changing reserves to state forest for timber harvesting! This practice continued for decades until the Forest Department began setting aside small areas for conservation and recreation from the 1960s onwards. Although government promises over the years to ban old-growth logging, legislation has quietly changed terms, and old-growth logging continues despite public protests. Challar Forest was logged in 2014 revealing 400 year old jarrah to be used for firewood and woodchips, creating anger within environmental groups in WA. The tiny remaining patches of old-growth jarrah it seems are too valuable to protect. However in 2022 the government announced plans to halt all old growth logging in Western Australia by 2024. Details are still as yet to be decided and old growth clearing and mining are still allowed but this is great news.
Jarrah was first logged in the 1840s, and it quickly became highly demanded around the British Empire. Some of its appealing qualities are its strength, durability and attractive appearance. Its uses were many, indoor high-quality furniture, general building construction including panelling, flooring and framing. Outdoor uses was extensive with heavy building construction, public works buildings and marine applications including bridges, piers and jetties, as well as fence posts and roads. Across Europe, jarrah blocks were used for roads with asphalt layered on top and also for underground construction for early railways in London, Paris, Berlin and Moscow! It was also shipped extensively across Africa and Asia for railway sleepers and of course as fuel for fires although jarrah is tricky to ignite. Second growth jarrah logs are still used for telegraph poles weighing up to 2 tonnes.
The largest areas with some protection such as Lane Poole Reserve just south of Dwellingup has a lot of great campsites available with at least 10 giant jarrah located there. The two biggest are both sign posted as King Jarrah which was a common practice started many decades ago to indicate to tourists that this is a large jarrah tree! Although only one is accessible by road now as ongoing bauxite mining nearby has closed road access for decades to the other tree. There is however, a scenic walking track to it but it is a day hike, or you can bush bash with a GPS like I used to do, prickles and all, but these days I've since found a safer way! Overall there are about 30 giant jarrah listed on the register, only a handful listed are signposted as King Jarrahs however, still standing around the Southwest forests.
Jarrah was first logged in the 1840s, and it quickly became highly demanded around the British Empire. Some of its appealing qualities are its strength, durability and attractive appearance. Its uses were many, indoor high-quality furniture, general building construction including panelling, flooring and framing. Outdoor uses was extensive with heavy building construction, public works buildings and marine applications including bridges, piers and jetties, as well as fence posts and roads. Across Europe, jarrah blocks were used for roads with asphalt layered on top and also for underground construction for early railways in London, Paris, Berlin and Moscow! It was also shipped extensively across Africa and Asia for railway sleepers and of course as fuel for fires although jarrah is tricky to ignite. Second growth jarrah logs are still used for telegraph poles weighing up to 2 tonnes.
The largest areas with some protection such as Lane Poole Reserve just south of Dwellingup has a lot of great campsites available with at least 10 giant jarrah located there. The two biggest are both sign posted as King Jarrah which was a common practice started many decades ago to indicate to tourists that this is a large jarrah tree! Although only one is accessible by road now as ongoing bauxite mining nearby has closed road access for decades to the other tree. There is however, a scenic walking track to it but it is a day hike, or you can bush bash with a GPS like I used to do, prickles and all, but these days I've since found a safer way! Overall there are about 30 giant jarrah listed on the register, only a handful listed are signposted as King Jarrahs however, still standing around the Southwest forests.
The above image shows typical jarrah bark. A soft, fibrous stringybark, always growing in the same nearly vertical direction. Younger, newer bark is reddish-brown, compared to the outer, older grey-brown bark. Jarrah grows on laterite soil producing a red gravel appearance and contains high amounts of aluminium ore from its bauxite components. Annual rainfall is between 700-1300mm. The forest ecosystem is complex with jarrah and marri dominating. To the east, wandoo (Eucalyptus wandoo) mix with the drier Jarrah Forest and further south yarri trees inhabit wetter areas of the Jarrah Forest. Around water courses flooded gum (Eucalyptus rudis) and paperbarks (Melaleuca) line rivers and swamps. Smaller understory tree species include sheoak (Casuarina) and banksia (Banksia) which grow throughout the Jarrah Forest. Also covering the entire Jarrah Forest are the ancient cycad (Macrozamia riedlei) and grasstree (Xanthorrhoea preissii) both living relics from Australia's Gondwana past. Many animals live in the Jarrah Forest including mammals such as the rare western quoll (Dasyurus geoffroii), quokka (Setonix brachyurus), quenda (Isoodon obesulus), western brushtail possum (Trichosurus vulpecula), western grey kangaroo (Macropus fuliginosus), various species of micro-bats and WA's native emblem the endangered numbat (Myrmrecobius fasciatus). Birdlife includes the endangered Carnaby's black cockatoo, tawny frogmouth (Podargus strigoides), bush stone-curlew (Burhinus grallarius), emu (Dromaius novaehollandiae), as well as various types of parrots, fairywrens, honeyeaters, several birds of prey and owls. At the forest floor, insect life recycles the soil adding nutrients and echidas (Tachyglossus acaleatus) eat termites of which I have seen many, as well as bobtails (Tiliqua rugosa). They are well camouflaged and unfortunately I have stepped on some before and got a little bite for it, but luckily no one seemed unharmed!
Due to extensive clearing and land usage, very little jarrah forest has remained or grown back. Initial logging was selective, but second-growth logging was mechanised, clear-felling which often disturbs the soil too much reducing the forests ability to thrive. In many areas, Monterey pine (Pinus radiata) has been planted as jarrah simply couldn't be rehabilitated.
To compound this problem has been the significant issue of dieback, a soil-borne water mould that infects the tree's roots. This causes root rot preventing nutrient absorption leading to the death of the tree, and often spreading to many other trees in the forest. I am careful not to explore forests in winter as wet conditions spread the zoospores. I also carry with me a solution to spray my 4WD tyres and wheel arches and my boots to further reduce to risk of spreading the disease.
In spite of these hardships, the Jarrah Forest continues to endure. The first time I found a noted grove of old-growth jarrah off Kinsella Road was a memorable experience. The light was failing and I thought I would have to give up, but I walked into a grey stand in a quiet section of forest and instantly knew I had found them amongst all the regrowth. These trees were growing near a rocky slope, they were never going to be giants so had not been logged. Their trunks were twisted but clean barrelled for 15 metres with heavy limbs and intricate canopy structures. In the 25 years since then, however, they have been logged, the road is no longer there and there is a pine plantation instead.
In the mid 1990s I took my family to the old Hoffman Mill for the Bridges Walk, a short bushwalk around some regrowth jarrah forest but for me, the attraction was a large remnant jarrah tree highlighted, a King Jarrah! On the drive up Logue Brook Dam Road massive felled jarrah logs began lining the road, their red heartwood vivid from recent rains. I'd never seen such a sight. There were dozens of logs 2 metres wide and 10 metres long, some bigger. We were saddened but amazed by the size of these logs. It was on the walk nearing the King Jarrah tree that further disappointment came. It was stumped at 50 cm from the ground, no rot, solid and recently cut with bark intact and sap still oozing around the edges. It was around 2.5 m wide, clearly, it was a magnificent giant. I later enquired about its demise but never got a real explanation, it wasn't supposed to be cut was all that I was told, there was little accountability in those days. Looking back I wish I took some pictures of the biggest logs lining that road, they were all removed a few years later.
I always appreciate the moment I am nearing a giant jarrah knowing how special each one is. There are still a few big ones left. I've measured all of the biggest jarrah on the WA significant tree list, there's just a few smaller ones left on the list I need to measure. People often tell me there’s areas still unexplored, but the Jarrah Forest was thoroughly surveyed. Despite my decades of searching, this is the one species I'm yet to discover a really big one by myself. The closest I've come to is the Murray Jarrah at 73 m³ in volume, a previous top ten jarrah I initially thought I'd discovered. The nearby and now fallen Amphion Jarrah at 70.8 m³ in volume, had more points so was the champion in that area. The Murray Jarrah I believe had the second most points so was not on the published list. I randomly parked next to it to measure the Amphion Jarrah. When I returned I thought I better measure it and it turned out bigger! I couldn't believe how easy it was to discover giant jarrah. I then noticed the large spray painted 'H' on its base, indicating this was marked as a protected habitat tree, like other large trees in the Jarrah Forest, so its size was already noted.
I've found around 10 jarrah relics (half alive) which would've had more than 50 m³ in volume once, and several more that would've had more than 60 m³ in volume once. I've also measured around 20 giants 3 m in DBH, mostly around the Perth Hills. These Perth Hills jarrah seem to have bigger bases than others further south, yet don't get the rainfall to become real giants, with shorter trunks than jarrah beginning from Jarrahdale (appropriately named) south. Most have been damaged and burnt from repeated fires, which, unfortunately is a hazard in the hot summer months. Overall I've measured close to 70 jarrah over 50 m³ in total volume since 2012. The hunt goes on!
HISTORICAL ACCOUNTS
There are hundreds of historic jarrah images depicting life around the mill of the early settlers and later of the logging era. Very few large jarrah trees are recorded however. The image below is by far the biggest historic jarrah tree I have seen. Known as the Holyoake King Jarrah, it grew in the small town of Holyoake, a few kms east of Dwellingup. I believe it was protected as a tourist attraction but did not survive the major bushfire around Dwellingup in 1961. The town of Holyoake was not rebuilt but no lives were lost. To estimate its total volume, I multiplied estimated volume at 10 m then I double that number. This is the average ratio difference for the biggest jarrahs at 10 m compared to total volume. Perth Hills jarrah are exactly 1 ½ times that ratio difference due to their shorter trunks and larger bases. I derived these ratios by averaging all the largest jarrah with single trunks to 10 m from my extensive database. I have done this on the other tree giants of the southwest of WA except for tuarts, as they often spit well before 10 m making the formula unreliable. I've done this on other historic trees and I believe it is the best method to estimate volume from just one image. This is of course assuming that image shows most of the lower trunk and ideally a person for scale, which most do. Many years ago I visited the state library and saw many images of what I would consider as giant jarrah. Those images are still only viewable at the library at this stage. Some are likely of current giants still with us, but were photographed when they were first discovered. Another trip to the state library may be in order to show the biggest giants of the past I can find.
I always appreciate the moment I am nearing a giant jarrah knowing how special each one is. There are still a few big ones left. I've measured all of the biggest jarrah on the WA significant tree list, there's just a few smaller ones left on the list I need to measure. People often tell me there’s areas still unexplored, but the Jarrah Forest was thoroughly surveyed. Despite my decades of searching, this is the one species I'm yet to discover a really big one by myself. The closest I've come to is the Murray Jarrah at 73 m³ in volume, a previous top ten jarrah I initially thought I'd discovered. The nearby and now fallen Amphion Jarrah at 70.8 m³ in volume, had more points so was the champion in that area. The Murray Jarrah I believe had the second most points so was not on the published list. I randomly parked next to it to measure the Amphion Jarrah. When I returned I thought I better measure it and it turned out bigger! I couldn't believe how easy it was to discover giant jarrah. I then noticed the large spray painted 'H' on its base, indicating this was marked as a protected habitat tree, like other large trees in the Jarrah Forest, so its size was already noted.
I've found around 10 jarrah relics (half alive) which would've had more than 50 m³ in volume once, and several more that would've had more than 60 m³ in volume once. I've also measured around 20 giants 3 m in DBH, mostly around the Perth Hills. These Perth Hills jarrah seem to have bigger bases than others further south, yet don't get the rainfall to become real giants, with shorter trunks than jarrah beginning from Jarrahdale (appropriately named) south. Most have been damaged and burnt from repeated fires, which, unfortunately is a hazard in the hot summer months. Overall I've measured close to 70 jarrah over 50 m³ in total volume since 2012. The hunt goes on!
HISTORICAL ACCOUNTS
There are hundreds of historic jarrah images depicting life around the mill of the early settlers and later of the logging era. Very few large jarrah trees are recorded however. The image below is by far the biggest historic jarrah tree I have seen. Known as the Holyoake King Jarrah, it grew in the small town of Holyoake, a few kms east of Dwellingup. I believe it was protected as a tourist attraction but did not survive the major bushfire around Dwellingup in 1961. The town of Holyoake was not rebuilt but no lives were lost. To estimate its total volume, I multiplied estimated volume at 10 m then I double that number. This is the average ratio difference for the biggest jarrahs at 10 m compared to total volume. Perth Hills jarrah are exactly 1 ½ times that ratio difference due to their shorter trunks and larger bases. I derived these ratios by averaging all the largest jarrah with single trunks to 10 m from my extensive database. I have done this on the other tree giants of the southwest of WA except for tuarts, as they often spit well before 10 m making the formula unreliable. I've done this on other historic trees and I believe it is the best method to estimate volume from just one image. This is of course assuming that image shows most of the lower trunk and ideally a person for scale, which most do. Many years ago I visited the state library and saw many images of what I would consider as giant jarrah. Those images are still only viewable at the library at this stage. Some are likely of current giants still with us, but were photographed when they were first discovered. Another trip to the state library may be in order to show the biggest giants of the past I can find.
This image of the Holyoake King Jarrah is from 1919, near the town of Dwellingup, it looks more like a red tingle! A tree hunting friend of mine Kim sent me this image. Apparently it was a popular post card in the Dwellingup Trails and Visitor Centre, but by the 1990s was no longer sold. I estimate it was 4 m in DBH with a base width of 5 m! Estimated total volume is about 116.2 m³, going with a volume at 10 m of 58.1 m³. Width at 10 m is about 1.8 m. By 3 m our current champ, the Looming Relic is wider but this tree may have been slightly larger in volume! Image is reproduced with permission from the State Library of Western Australia.
The Dwellingup Log was harvested by Whittakers Sawmillers Concession, 15-20 km north of Dwellingup in the late 1960s. It was displayed here sometime after 1970. Roughly 2.5 m in diameter at the near end, to estimate its size, I added another metre and imagined a base width of 3.5 m. I then did diameters like I usually do to 10 m then doubled that figure. The restored potential total volume is 70.6 m³. Logs this size lying horizontally look even bigger than vertical, especially when you can see them up close. Although a bit sad to see, I’m sure many people appreciate this famous landmark as a visible reminder of a past age.
This image of the Nannup Jarrah is from 2012. This was a previous top ten jarrah on the list below. I placed it in the deceased section as I believed it had fallen over when I went to visit it in 2022. Apparently I mistook a giant, fallen jarrah very close to this tree with my GPS beeping that I’d arrived at my destination, only it hadn’t fallen over! A tree hunting friend of mine Nick has shown me some great, HD drone footage of the Nannup Jarrah that it is still standing, but does appear dead in 2025! So, unfortunately it's in the right section. It was 2.7 m in DBH and 78.3 m³ in total volume and one of the first really large jarrah trees I saw. A long way from anywhere, I came to realise that giant jarrah were simply potentially anywhere in the vast Jarrah Forest, along with marri and yarri, making my adventures real day trips involving hundreds of kilometres of driving, arduous hiking and safety a real highlight, for a fitting reward!
This image of the Mount Wells Monster is from 2025. It's the largest jarrah relic I've found over the decades of searching. This ruinous beast is 4 m in diameter at its base and a restored 2.8 m in DBH. I decided to measure the mass of shattered wood lying around it to see how big it was. The wood in the foreground is part of the main trunk which has shattered and is 2 m thick at around 10 m for a restored volume at 10 m to 48.2 m³. Doubling that figure gets a restored potential total volume to 96.4 m³, making this the fourth biggest known jarrah! What a pity it was destroyed only a few years earlier, I would have loved to have come across it alive.
This image of the Waroona Snag is from 2023. I found it after my trip to ALCOA Willowdale and Myara mine sites where I measured two giant jarrah over 70 m³ in volume, including the top ten Myara Jarrah. I was stunned, this seemed bigger than those and almost an exact replica of the base of the mighty Holyoake King Jarrah! It's 5.1 m in diameter at the base and a restored 3.3 m in DBH, although in this view it looks over 3.5 m in DBH because it's oval in cross section! While it tapers, the broken top is a measurable 11 m and 1.3 m in diameter at 10 m. This gives it a volume of 44.2 m³ at 10 m, for a restored potential total volume of 88.4 m³ once, making this the seventh biggest jarrah known.
This image of the Gnarly Giant is from 2025. Found 17 km east of Dwellingup, it's a living relic but heavily battered by the elements. With a few other giants lining this road, they were definitely saved decades ago by some forward thinking foresters. Its slightly sloping base is 3.8 m wide, with a restored 2.5 m in DBH. With one giant strip of living bark twisting around its vast trunk, which is snapped off at 15 m, width at 10 m is a minimally restored 1.9 m in diameter. At 10 m, volume is 40.7 m³, for a restored potential volume of 81.4 m³. In its current state, it is 56.8 m³ in total volume.
This image of the Scorched Beast is from 2025. Only 25 kms directly east from my house, I can't believe such a giant was relatively nearby! To be fair, it's several kms from nowhere on a washed out, steep and rocky road that required me to engage rear diff lock several times, reduce tyre pressure, and use low range gear 1 and 2 in my 4WD. This was turning into a typical Perth Hills drive, a few scattered large jarrah, 2 m in DBH half burnt, but none even close to 50 m³ in volume. Then, in a little gully a few larger jarrah and marri and this giant emerged. I knew it was big, but when I approached I was stunned. Unfortunately barely alive, leaning 6 m off centre and totally hollowed out, this jarrah is hanging on, just, with several healthy branches. I measured a base width of 4.8 m and 3.1 m in DBH, both semi restored. I measured it with the trunk still nearly fully measurable to 10 m, before breaking by 12 m. I got a volume of 55.4 m³ at 10 m, giving me enough confidence to estimate a restored potential volume of 83.1 m³! Remember, for the Perth Hills jarrah, the ratio at 10 m is 1 ½ times for total volume, having shorter trunks and wider bases.
TOP TEN JARRAH
TOP TEN JARRAH
