Californian Redwood

24.05.17

Californian redwood (Sequoia sempervirens) is the tallest tree species on Earth, growing to over 100m in height and about 3m in diameter. It is a softwood tree, native to the United States of America.

Overview

The timber of the Californian redwood has a pink to deep red heartwood and pale sapwood. The heartwood is moderately strong, light, stable and durable, making it a popular choice for outdoor furniture, lining boards and joinery.

While the tree grows well in Australian conditions, it is not grown as a commercial crop. Potential has been identified for Australian grown Californian redwood to present an alternative to imported western red cedar; however the long establishment time to harvest (more than 25-30 years) is a daunting prospect for any investor in an untested market.

The Californian redwood is considered an easy tree for a skilled operator to manage. As a softwood it is easy to prune, it naturally grows straight therefore thinning is not normally required and the timber is easy to dry and mill with portable or on-farm equipment.

Facts and figures

Californian redwood (Sequoia sempervirens) is the tallest tree in the world, growing to 100m
Californian redwood is considered a possible alternative timber to western red cedar

Californian redwood has been grown in Australia in plantations for more than 70 years in Victoria, New South Wales and Tasmania. It was rejected in favour of pinus radiate because it was more site specific, slower growing in the early years and had a red heartwood
It is considered an easy species to harvest and mill on farm by a skilled operator

Production status

Californian redwood has been grown in plantations in Australia in the past in Victoria, New South Wales and Tasmania.

Map of current and potential growing regions

Uses

In the United States of America, Californian redwood is used in decking, fencing, railway sleepers, bridge timbers, posts, shingles, exterior siding, doors, panelling, furniture and general construction.

In Australia it is believed to have potential to produce timber for products currently made from imported western red cedar, such as window and door frames, lining boards and outdoor furniture.

Production Requirements

Growing regions

There is no Californian redwood grown commercially in Australia. An experimental site of the species grows in south west Victoria; and Californian redwoods planted as ornamentals or urban plantings have been observed growing well in both temperate and subtropical areas of Australia and New Zealand.

Soil type

Californian redwoods prefer heavy moist soils in cool climates and will tolerate waterlogged clays. In sandy soils, the tree will suffer die-back if the soil becomes too dry.

Climate

The natural climate of the Californian redwoods is a wet temperate coastal region of the United States, but the species has grown well in temperate and subtropical areas in Australia and New Zealand.

Varieties

Californian redwood (Sequoia sempervirens) is an evergreen, long-lived tree in the cypress family Cupressaceae. There is no information on recommended varieties or cultivars to grow in Australia, however there are many very successful plantings.

Planting and crop management

Californian redwoods can be grown from cuttings or seed and a small number of specialist nurseries grow seedlings for plantations from seed imported from New Zealand or the United States of America.

When selecting the planting site, accessibility of the trees for maintenance and harvesting is a key consideration. Being on flat, accessible land, with good access roads and room to manoeuvre heavy equipment will make management easier and keep costs down over time.

Once the site has been selected, and the soil prepared, plantings are generally spaced between 6–8m to allow for growth. The soil should be kept weed free in order to maintain subsoil moisture. Planting should be done when there is adequate soil moisture, for example after a rainfall event.

Californian redwood can take more than five years to reach two or three metres in height, so early and continual protection from grazing animals and weeds is important.

If seeking to grow high quality sawlogs, pruning of branches (up to 8 metres) will be necessary to encourage straight, defect free timber. This is easy to manage as the Californian redwood’s horizontal branches rarely grow very large and the soft wood is easy to cut.

Unlike other commercial tree species, most Californian redwood naturally grow straight, so thinning for form and quality may not be required.

Californian redwoods exhibit slow growth at first but once established, their growth can match that of the fastest eucalypts. In optimum growing conditions, they can add around 2.5cm per annum in diameter.

Weeds, pests, and diseases

Weed control in plantations is particularly important before planting and may be required for at least the first two years of growth, or until the trees reach two metres in height. Competition by weeds for sunlight, nutrients and moisture can reduce growth rates in young trees.

As Californian redwood is not a commercial species in Australia the impact of any pests and diseases is not fully known.

Infrastructure Requirements

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.

Californian redwood is considered an easy timber to mill. A skilled operator could manage the harvest and drying on farm, and using a portable mill, produce timber that meets specifications for direct sale to a customer.

Harvesting & Processing

Initial site selection for commercial trees will have an influence on harvest method — well-spaced trees near access roads will be easier and cheaper to harvest.

Harvesting is generally undertaken in two ways. If timber production is the sole objective of the plantings, then clear felling is the logical method. However, if the trees form part of a shelterbelt, then harvesting of small volumes over a longer period of time is the more practical solution.

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 may 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.

Californian redwood is considered an easy timber to mill. A skilled operator could manage the harvest, drying and, using a portable mill, could meet specifications for sale directly to a customer.

Markets & Marketing

Californian redwood is not a commercial plantation species in Australia, therefore the market for the timber is not known. It is thought that Californian redwood might make a good replacement for imported western red cedar. In New Zealand, where there are commercial plantations of Californian redwood, it is believed that as access to natural stands of the tree in the United States is increasingly restricted, there is considerable potential for an export market to develop for New Zealand.

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 or more 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 affect the profitability of a commercial timber enterprise, generally speaking, when the plantation is more than 100km from the processing centre (or road conditions are difficult), there may be higher transport costs. The closer the planting is to the processing centre, the greater the return for any given product, particularly if providing a high volume of a lower value timber, such as pulpwood and woodchips.

Planting and managing for high quality sawlogs can counter some of the market uncertainty and absorb transport costs, 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.

Considering local markets for the timber can provide options should future markets change as described in the Risk/challenges section. Local markets could include the building or construction industry in the region, farm use as fence posts, or domestic use as firewood. For a skilled operator, Californian redwood is considered an easy tree to harvest and mill. While there is no large, commercial market for the timber in Australia at this time, Californian redwood is a valuable timber for use in furniture making and local markets may exist for small amounts of timber.

Risks & Regulations

Risks/challenges

For commercial tree operations in general, uncertainty and risk are inherent due to the long period of time between establishment and harvest. For Californian redwood in particular this could be up to 40 years.

Some of the risks for commercial tree operations in general 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, 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 watertable 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.

One environmental benefit provided by Californian redwoods in particular is through their dense fibrous root system that tends to graft together forming a root mat that binds the soil. This makes it a useful tree in areas prone to tunnel erosion (that is, where the movement of excess water creates “tunnels” in the soil).

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.