Red Cedar

Overview

Not to be confused with western red cedar (Thuja plicat), red cedar is a member of the Meliaceae family and can grow to around 60m in height with a trunk that can reach 3m in diameter.

Red cedar is one of Australia’s few native deciduous trees (where leaves seasonally fall and regrow). The timber is red in colour, easy to work and very highly valued. While considered commercially extinct, trees are still occasionally harvested from sources grown in the 1950s, which have a trunk size of approximately 1m.

In addition to the timber’s high value, red cedar is a fast growing tree with the ability to survive drought, fire and moderate frost, which raise its potential as a plantation species. However, commercial plantations have been unsuccessful due to the prevalence of the cedar tip moth, which causes dieback and stimulates the tree to grow additional branches, making its shape unsuitable for commercial production. Commercial tree operations are inherently high risk and highly specialised and are long term investments with the time between establishment and harvest ranging from 30-50 years.

Facts and figures

Red cedar was named “red gold” by Australia’s early settlers, who used it extensively in furniture, construction and boat building
It can grow to 60m tall, with a trunk that can reach 3m
The tree was over harvested in the early 20^th Century to a point that it is now considered commercially extinct
Availability of this timber is now limited
Red cedar is a fast growing tree with good tolerance to drought, fire and frost
It has not been a successful plantation tree due to its susceptibility to the cedar tip moth
It may be a suitable tree to grow interspersed with other species

Production status

Red cedar is not grown in commercial quantities in Australia. Trees are occasionally harvested on the Atherton Tableland of Queensland by the state’s forestry agency. Because of the scarcity of Australian timber, red cedar timber is imported to meet demand.

Efforts to grow red cedar as a plantation tree have generally failed due to attack by the cedar tip moth. However, red cedar has been successfully grown in shady areas of temperate regions, with a nurse crop to protect them from cedar tip moth.

Map of current and potential growing regions

Uses

Red cedar is milled to provide timber used mainly for appearance-based internal applications such as decorative veneers, panelling and furniture. It has also been used for boat building and carving.

Production Requirements

Growing regions

Red cedar is found in rainforests along the east coast of Australia. The main areas of distribution are between Ulladulla in New South Wales, and Gympie in Queensland. Further north it occurs on the Eungella Range west of Mackay and the Atherton Tableland.

Red cedar is also native to coastal regions of Papua New Guinea, south east Asia and reportedly, India.

Soil type

Red cedar prefers well-drained, rich alluvial or volcanic soils, derived from basalt and is typically found growing on red soil plateaus and in gullies along the Great Dividing Range, within the natural distribution range of the tree.

Climate

The natural habitat for red cedar is tropical, subtropical and warm temperate rainforests, demonstrating its preference for warm humid to warm sub-humid climatic conditions, with rainfall in excess of 1200mm. However, red cedar has been observed growing well in temperate regions, in moist sheltered gullies and along stream banks, protected from frost.

Varieties

Red cedar has not been cultivated commercially so there has been no reason or attempt to select favourable lines or types of the plant for the purpose of developing a variety for cultivation.

The Australian population of red cedar was originally treated as a species distinct from its neighbours in south east Asia, and as such named T. australis. Later, its classification was changed to that of the other red cedar trees T. ciliate. Sometimes the tree in Australia may be referred to as T. ciliata var australis.

Planting and crop management

Commercial trees can be integrated into existing agricultural systems to complement farm output or can be a separate use of available land, managed in plantations.

When selecting a site for establishing a timber plantation, accessibility of the trees for maintenance and harvesting is a consideration. Being on easily accessible land, with good access roads and room to manoeuvre heavy equipment will make management easier and keep costs down over time. Red cedar is a rainforest species, so frost prone and exposed sites may not be suitable. For exposed sites, establishing a windbreak to protect the trees could be a viable solution. Ensure the site has adequate drainage, for example, by planting on a slight slope.

Planting a nurse crop is recommended to protect red cedar from the cedar tip moth. Silky oak (Grevillea robusta) has been observed as suitable for mixed planting with red cedar due to its rapid growth, which provides crucial shade, and its narrow crown, which means it won’t starve red cedar of light. Interplanting of red cedar is becoming common in Latin America where it is being grown at 10-metre spacings, amongst coffee, maize, cocoa and citrus trees.

Planting red cedar during the wet season, if possible, will increase the establishment success of seedlings. Planted or emerging seedlings need to be protected from grazing animals by fencing or tree guards.

High density planting (2 x 3m or 3 x 3m spacings) promotes the development of straight and tall timber by encouraging competition for light. If planting red cedar for high quality sawlog production, pruning will be of critical importance in the first few years of growth. The lower branches need to be selectively pruned to achieve a straight, central stem of 3–4 metres in length.

Red cedar responds well to light fertiliser applications, mulch and water in dry periods.

Weeds, pests, and diseases

Weeds need to be managed while the trees are young to maintain the soil moisture and nutrient levels available to the red cedar. As the trees age, weed management is not as crucial, and there is some evidence to suggest weeds will contribute to an understorey environment that supports mature trees.

Although red cedar is considered very easy to grow, it is highly susceptible to attack by the cedar tip moth (Hypsipyla robusta) making it very difficult to produce straight stems for timber production.

The moth lays its eggs on the tree’s highest, leading shoot. The larvae then burrow into the stem causing dieback, which stimulates growth of additional branches producing a multi-stemmed tree with little timber production value. A plantation monoculture makes the red cedar vulnerable to cedar tip moth because a plantation will not support the natural predators of the moth nor provide the young trees with protection of other vegetation.

Chemical control of cedar tip moth has been unsuccessful for a number of reasons. Primarily, the high rainfall climates preferred by cedar tip moth limit the effectiveness of spray insecticides. Plus, once the larvae have started burrowing into the tree, they are protected from contact with any insecticides sprayed on the tree. The number of chemical applications required to control cedar tip moth are uneconomical and considered environmentally unacceptable.

Infrastructure Requirements

Land is the main infrastructure requirement for commercial tree growing.

If planting trees on a small scale and integrating them into the agricultural enterprise as windbreaks and shelterbelts, then manual maintenance, including pruning and thinning, can usually be managed with a chainsaw and farm equipment.

If planting a commercial plantation of high value sawlogs, then tree farm-scale, tractor-based forestry equipment may be necessary, including logging winches and chains. Unless the plantation is large and consists of high value logs, it will not be economical to purchase specialised harvesting equipment or modify existing farm equipment to undertake harvest. Contractors with specialised equipment and machinery may also be considered.

Harvesting & Processing

Initial site selection for commercial trees will have an influence on harvest method—well-spaced trees near access roads will enable easier and cheaper harvesting. As red cedar is generally grown as part of a mixed species planting, harvesting is best done in small volumes over a longer period of time.

The timber is usually sold in two ways; either as ‘standing’ where a professional contractor pays a ‘stumpage rate’ to harvest and transport the logs, or ‘mill door price’ where logs are delivered to the timber mill having been harvested and transported privately or using contractors.

Unless the plantation is large and consists of high value logs, it will not be economical to purchase specialised harvesting equipment or modify existing farm equipment to undertake harvest. If the trees are large, pruned and well spaced, specialised equipment may not be required at all. A trained operator using a chainsaw, farm tractor, loader and log trailer may be able to undertake the job in a cost-competitive way.

Markets & Marketing

It is important to consider current and/or future markets before choosing which commercial tree species to grow. However, with commercial trees taking around 30 years to provide a return on investment (in most cases) it is difficult to accurately predict future market opportunities at establishment.

Distance from markets will impact on profitability of the enterprise, particularly if providing a high volume of a lower value timber, such as pulpwood and woodchips. Therefore planting and managing for high quality sawlogs can counter some of the market uncertainty, as it is often easier to find markets for high value timber, even with longer transport distances involved. High value timber requires ongoing maintenance of trees, ensuring they are managed for the specifications particular to high value markets, essentially: good form, diameter and limited defects.

Generally speaking however, distances greater than 100km (or with difficult conditions, for example dirt roads), will impact on the profitability of commercial trees due to higher transport costs. The closer the plantings are to the processing centre, the greater the return for any given product.

Consideration of local markets for the timber provides options should future markets change as described in the Risk/challenges section. Local markets could include the building or construction industry in the region.

Risks & Regulations

Risks/challenges

Uncertainty and risk are inherent in all commercial tree operations due to the long period of time between establishment and harvest.

Some of the risks include:

mills closing or relocating, leaving plantings at an uneconomical distance from processors
timber preferences or ‘fashions’ changing, resulting in decreased markets as certain colours or grades of timber fall out of favour with designers and builders and consumers
government policy changing, impacting on industry structure and profitability
alternative products developing, resulting in a falling demand for timber.

Alternative benefits from commercial tree plantings should be investigated to help reduce exposure to these risks. It is recommended that a short-, medium- and long-term return or benefit be identified when considering planting commercial trees. For example, a short-term benefit could relate to carbon sequestration or water table abatement. A medium-term benefit may be derived from the trees providing a windbreak or shelterbelt for crops and livestock, and a long-term benefit might be income from harvested timber.

To further manage risk, it is recommended that tree selection take into account the potential for local use for the timber. A timber versatile enough to be processed and used locally will limit some of the uncertainty around future markets if there are alternative opportunities to earn income. For example, local markets could include the local building and construction industry, farm uses such as fence posts, and domestic uses such as firewood.

Regulatory considerations

If seeking to establish a commercial plantation (the definition differs by state, but is generally defined at around 30 or 40 hectares) liaison with the relevant state government agency will be necessary. Regulatory systems vary across states, with some requiring plantations to be authorised and others requiring plantations to meet legislative requirements and/or a management Code of Practice.