River Red Gum

Note Number: AG0902
Published: October 2001
Updated: July 2009

This Agriculture Note provides information about river red gum (Eucalyptus camaldulensis) and its uses.

Introduction

The river red gum (Eucalyptus camaldulensis) is the most widely distributed eucalypt on mainland Australia. It occurs naturally along inland rivers, dry watercourses and flood plains in every state except Tasmania.

This species will adapt to most soil types however prefers deep clayey subsoils. In order to achieve maximum growth, access to the water table or periodic flooding is required.

Description

The river red gum is a medium to large size tree that can grow to heights of 50 metres. In its natural form, it grows with a thick trunk, heavy twisting branches and a spreading open crown. The dull cream or grey gum bark is often shed irregularly leaving dark grey patches.

The slender adult leaves are variable in length from 9 to 20 centimetres and are commonly a dull greyish-green on both sides. Leaf venation is fairly obvious.

The creamy yellow flowers of the river red gum appear in summer. Fruit form after flowering, usually at the tips of the canopy branches. It develops on slender stalks in clusters of seven but can form with five to eleven fruit per bunch. Natural seed fall will normally occur on hot north wind days over summer. Seed takes about 12 months to develop.

River red gum produces a red durable hard timber that is resistant to decay and termites.

Uses for red gum timber

River red gum timber has been used extensively since European settlement. Conventional uses include:

• on-farm usage (fences, posts and poles) (Figure 1)
• regular heavy construction (beams, bridges, stumps, frames, sills, panels, flooring and lining)
• particle board, plywood, pulp and veneer
• railway sleepers, non-dwelling buildings and firewood
• furniture and turnery

 River red gum timber can be sold as sawlogs or as kiln-dried hardwood. Some alternative uses of this species include harvesting the gums and oils for aboriginal and conventional medicines. It is also used extensively for nectar and honey production, as well as for the production of charcoal.

Growing river red gums – choosing a provenance

Due to natural genetic variation, tree species vary in their growth habits and wood properties. These natural variations are unique to each provenance or local growing environment.

Selecting a suitable provenance to plant is vital for success. It ensures some resistance to disease, drought, flooding, frost and salt tolerance. A suitable provenance also leads to best growth rates and tree form, desirable wood properties and, quality leaf oils.

For example, Lake Albacutya provenance has a high tolerance to saline soils and waterlogging. This is represented by a growth rate of up to one metre per year.

Although provenance trials on red gums are only beginning, the Lake Albacutya provenance and the Douglas provenance already stand out as two of the better provenances to be planting in saline or waterlogged areas.

It is important to note that planting tropical provenances from Queensland for example, should be avoided in Victoria.

Hybrids of river red gums crossed with either southern blue gum (Eucalyptus globulus) or rose gum (Euclayptus grandis), are being developed in an effort to improve the form and growth rates of river red gum while retaining their tolerance to waterlogging and salinity. Progeny from these crosses is variable and still being tested, but the better hybrids identified so far have been cloned and clonal stock is available from some nurseries.

Establishing red gums for timber production

Establishment options for landholders are dependent on the following factors:

• Costs
• Objectives – plantation verses regrowth
• Economics of selling timber
• Ease of marketing timber
• Labour requirements
• Risks and uncertainty

Two good means of establishing commercial red gum timber production areas are by direct seeding and by management of natural regeneration.

In low rainfall districts, the small outlay costs of these two methods can offset the long rotations required. Self thinning of the high stocking rates resulting from these establishment methods will occur eventually but will take many years. To improve growth rates, managed thinning will be required and this can be very labour intensive.

Planting of red gum seedlings to establish a timber production area can be costly but stocking rates can be controlled and therefore growth rates improved. Due to the branching tendencies of young red gum trees it may be less effective than the seeding methods, although more work needs to be done in this area.

Present and future demand predictions

There is a constant demand for red gum timber as firewood, charcoal and low-grade products such as railway sleepers. There is also good demand for river red gum timber for furniture, cabinet making and flooring with this demand being dependent on the timber being kiln dried properly.

Potential growers of river red gums for commercial output need to value-add on the farm if possible. This will increase the value of the timber and yield higher returns. Value adding techniques for sawn timber include basic milling, air-drying and (if possible) further milling. Processing and drying firewood on farm can also increase returns.

Properties of red gum timber

Table 1 describes the general properties of red gum timber.

During the drying process, surface checks and warping can occur. Placing weights on the stacks as they dry can help in preventing this. River red gum timber can also season well in air-dried stacks.

The timber of river red gums is considered to be difficult to work due to its hardness and interlocking grain. However, the timber polishes well and can exhibit an attractive, decorative grain.

Table 1. Properties of red gum timber

References

Boland, D.J., Brooker, M.I.H., Chippendale, G.M., Hall, N., Hyland, B.P.M., Johnston, R.D., Kleinig, D.A. & Turner, J.D. (1992) Forest trees of Australia, Melbourne: CSIRO Publications.

Costermans, L. (1981) Native trees and shrubs of south-eastern Australia, Sydney: Weldon Publishing.

Further information

Refer to other Farm Forestry Notes that cover different aspects of private native forest management one the forestry section of the DPI website:

www.dpi.vic.gov.au/

Contacts

Department of Primary Industries Victoria

Ph: 136 186

Acknowledgement

This note was developed by Virginia Forrest with the assistance of Allyson Lardner and published in October 2001.

It was reviewed by:

Philippa Noble, Farm Services Victoria. July 2009.