Sugar gum
Sugar gum (Eucalyptus cladocalyx) is a slow-to-moderate growing Eucalyptus that prefers 600 mm or more of rainfall annually and sandy clay loams to gradational clay soils, but can also tolerate duplex texture profiles. it is a highly durable species that is very tolerant to dry sites. It is extensively grown in shelter and timber belts in western Victoria.
Table 1: General characteristics for sugar gum
Characteristic | Description |
|---|---|
Botanical name | Eucalyptus cladocalyx |
Growth rate in preferred conditions | Slow to moderate |
Estimated rotation length (yr) in preferred conditions to produce 60cm diameter at breast height | 30–35 |
Preferred annual rainfall (mm/yr) | 600+ |
Minimum rainfall (mm/yr) | 400 |
Preferred elevation (m) ASL | 0–250 |
Preferred landscape position | Away from frost-prone areas |
Preferred soil | Sandy clay loams to gradational clays. Can also tolerate duplex texture profiles. |
Prohibitive soil | Uniform deep sands and very heavy clays. Waterlogged soils. |
Poor drainage tolerance | Low–moderate |
Dry site tolerance | High |
Frost tolerance | Low |
Pest and disease problems: trees planted on unsuitable sites are more prone to insect and disease issues | Gum tree scale, leaf blister sawfly, chrysomelids and Christmas beetles |
Table 2: Timber characteristics for sugar gum
Characteristic | Description |
|---|---|
Strength: seasoned timber only | SD3: moderate/high |
Durability: in ground | above ground | 1 | 1 |
Drying: green to 12% moisture content | Dry carefully and slowly to avoid surface checking. Shrinkage about 6.2% radial and 10.5% tangential. |
Main commercial products | Outdoor furniture, decking, cladding, joinery, flooring, railway sleepers, fencing and firewood |
Bushfire resistance: measured by bushfire attack level (BAL) | BAL 12.5 and 19 – all AS3959 required applications |
Least attractive features | Potentially allelopathic, therefore having limitations regarding silvopasture application. Frost tenderness. |
Most attractive features | Dry site resilience. Relatively wide site tolerance and durable (rating 1) timber. Strong coppicing species. |
Status as a plantation species | Extensively grown in shelter and timber belts in Western Victoria over a long period. Often coppiced. Has potential in other drier areas (rainfall less than 700 mm per yr) where frost is not an issue. |
Note: Timber characteristics and durability are based on Australian Standard: Timber Natural durability ratings (AS 5604–2005). Refer to the Appendix for an explanatory table. Where (?) applied, rating is based on field experience.
Note: Bushfire resistance measurement is based on naturally bushfire resisting timbers, which are those with inherent bushfire-resisting properties. For more information refer to Australian Standard 3959:2018.
Assumptions and notes
- Sites considered for planting contain at least one metre of soil above an impeding layer (e.g., bedrock or layer impenetrable to roots).
- Please note that most (if not all) eucalypts in Gippsland grow best on sheltered sites.
- Overall slow drying time across air and kiln-dried schedules is recommended to minimise drying degrade. This is the best starting point for inexperienced operators.
References
Beadle CL and Brown AG (eds) 2007. Acacia utilisation and management: adding value. RIRDC Publication No. 07/095, Rural Industries Research and Development Corporation, Canberra.
Boland DJ et. al (1992). Forest trees of Australia. CSIRO Australia.
Bootle KR (1983). Wood in Australia – Types, properties and uses. McGraw Hill, Australia
Carnegie AJ (2002). Field guide to common pests and diseases in eucalypt plantations in NSW. Research and Development Division of State Forests, NSW.
Clarke B, McLeod I and Vercoe T (eds) 2009. Trees for farm forestry: 22 promising species. RIRDC Publication No. 09/015. Rural Industries Research and Development Corporation, Canberra.
Mortimer J (2003). A selection of alternative timbers. Taitua Books, NZ.
National Association of Forest Industries (2004). Timber species and properties, revised edition. Timber Manual Datafile P1
Nicholas ID, Gifford HH and Kimberely MO (1997). Siting black walnut. FRI Bulletin no. 188
Phillips C (1996). Insects, diseases and deficiencies associated with eucalypts in South Australia. Primary Industries SA Forests.
Poole B, Waugh G and Yang JL (2017). Potential for growing and processing durable eucalypts in New Zealand. Publication No. SWP-T036. Solid Wood Innovation. Specialty Wood Products Research Partnership.
Reid R (2017). Heartwood. The art and science of growing trees for conservation and profit. Melbourne Books.
Tepper CJ (2002). Plantation eucalypt species for solid wood products – a profile of Eucalyptus muelleriana. Gottstein Fellowship Report for the Gottstein Memorial Trust
Tepper CJ (2008). Site Matching and Establishing Eucalypt Sawlog Species in Southern Australia. In Beadle CL and Brown AG (eds) 2008. Plantation eucalypts for high value timber. RIRDC Publication No. 08/113, Rural Industries Research and Development Corporation, Canberra.