Tasmanian Blackwood Growers Cooperative

This page provides information for farmers and landowners who may be interested in joining the Cooperative and growing commercial blackwood. Once the Cooperative is established and gains Government financial support under the TFIA, the Coop will provide financial and technical assistance to farmers and landowners wishing to grow commercial blackwood.

The objective of the Coop is to grow quality blackwood timber and make a profit. Along the way there will be much to learn, new skills to develop and knowledge to share. We will develop close ties with our blackwood-growing colleagues in New Zealand and Chile, and with the blackwood industry.

See the Proposal page for details of the blackwood coop proposal. The other pages also provide useful information about growing blackwood, including the economics under the Resources page.

Site requirements

Considerable experience in both Australia and New Zealand has shown that to grow blackwood successfully in plantations the planting site must be carefully selected. Blackwood is a very hardy tree capable of growing in a wide range of sites, but good sites are needed to grow commercial blackwood. To ensure planting sites meet the selection criteria the Coop will inspect and evaluate all sites nominated for planting.

The Coop will have a policy of only establishing blackwood plantations on already cleared pasture or existing plantation land. No native forest will be cleared for blackwood plantations.

Climate/rainfall/soil moisture

Successful commercial blackwood plantations require good stem form and fast growth. Research has shown that growth rate and stem form are positively correlated. This is achieved where annual rainfall is above 1000 mm per annum. Having good soil moisture during the growing season (October – March) is also important.

Blackwood grows naturally across much of Tasmania, but is rarely found growing above 1000 metres altitude. It can survive mild frosts, but is killed or severely injured by severe frosts (<-5 °C). Frosts during the growing season will cause damage to new growth. Therefore planting in areas prone to severe frost such as high altitude sites (approx above 350m), or frosty hollows should be avoided.

Topography/shelter

When grown in an open environment like a plantation or paddock blackwood has a natural tendency to be heavily branched rather than tall and straight. Exposure to strong or persistent winds is one condition that causes blackwood to grow bushy. To grow quality blackwood sawlogs we need to manage this branching. Exposure also increases the risk of physical damage to the trees, so shelter from winds is very important.

Shelter is best provided in gullies/valleys or leeward slopes. It may also be provided by existing vegetation such as wind breaks, plantations or native forest. Blackwood grown in these sheltered environments has a greater tendency to grow tall and straight. Lower slopes and gullies also provide a better soil moisture environment to help blackwood maintain good summer growth.

Soils

Blackwood can grow on a wide range of soils, but best growth is on free-draining loams such as sandy-loams or clay-loams such as the krasnozems on basalts in the north east and north west. Poorly drained soils or heavy clays should be avoided. The blackwood swamps of the north-west are seasonally flooded but generally well drained. They are not stagnant swamps.

Because of these particular site requirements suitable planting areas will be small and scattered across the rural landscape. As blackwood plantations are high-value and relatively intensively managed (at least for the first 10 years), this small-scale, dispersed nature of the resource shouldn’t present major problems.

Establishment

Having selected a good site for the plantation, the next key to successfully growing commercial blackwood is proper establishment. Success requires getting the blackwoods properly planted and growing as quickly as possible. This involves good planning, weed control, soil preparation and protection from browsing.

Planning

A bit of thought and planning will help ensure the blackwood plantation is successfully established, managed and harvested.

Legislative

Under the Forest Practices Act 1985 new plantations of less than 10 hectares do not require a Forest Practices Plan. However on cleared pasture sites care will be needed in terms of soil, drainage and geomorphology values.

Practicalities

Access to the site for establishment and management must be considered, especially if the site is steep and/or inaccessible to vehicles. If the site is inaccessible to vehicles how will the site be prepared for planting? What about ongoing weed management? How might future harvesting be done?

Weed control

Blackwoods have a fine shallow root system. As such they are poor competitors against weeds when they are young. If the site has woody weeds such as bracken, gorse, blackberries, etc. these need to be removed. Grass needs to be sprayed in a 1 metre radius around each planting site. Grass competition will need to be controlled for at least the first 5 years following planting to allow the blackwoods to become well established.

Soil preparation

If the site has a heavy loam soil or is compacted it will need to be ploughed or ripped. This will also make planting easier.

Protection

Blackwood trees are extremely palatable to a wide range of animals including domestic stock, wildlife and vermin. Protection of the plantation from browsing for the first 5 - 10 years is critical, in that it requires constant vigilance and management. Protection is possibly the most costly aspect of blackwood plantations. Tree guards and/or fencing are expensive. Therefore care and planning is required to optimise the level of protection against the costs involved. In small plantations (<2 ha) tree guards may be the most cost effective protection. Larger plantations will require thought and planning to provide sufficient protection against likely browsing animals while minimising fencing costs.

Plants and planting

Blackwood is in the very early stages of domestication (cultivation, selection and breeding), so that planting stock is based on seed collected from native stands. A selection and breeding program is needed to begin the process of improving blackwood growth, wood quality and consistency. Planting is normally done in Autumn. This gives the plants time to get established before the following spring growing season.

Management

The final key to successfully growing commercial blackwood is the ongoing management, particularly during the first 10 years following planting. This includes pruning, weed control and ongoing protection from browsing. The success of the Cooperative will be driven by regular site visits to ensure good ongoing plantation management is provided.

Pruning

Producing quality appearance-grade timber in plantations requires growing trees that have a straight, branch-free 6 metre-long bole. This involves regular (annual) pruning to maintain a straight stem and control side branches. The trick here is to schedule the pruning annually. Learn the correct pruning technique and apply it regularly.

Weed control

Weed control, especially grass and vigorous woody weeds need to be controlled annually for at least the first 5 years following planting, to help maintain fast growth and reduce the fire risk.

Protection

Up until about age 4 the trees will need to be protected from low browsers such as wallabies, hares and rabbits. Protection from livestock is needed until the trees are about 12 cm stem diameter. 

By about age 10 years the trees should be fully pruned, be largely in control of the site in terms of weed competition (unless there are blackberries), and no longer in need of protection from browsing.

Native blackwood forest

There are still areas of native blackwood forest on private land in Tasmania, particularly in the north west and north east. This forest has potential to be managed for sustainable wood production and/or for its genetic resources as part of a blackwood selection and breeding program. Landowners with native blackwood forest wishing to achieve either of these objectives are encouraged to support and join the Cooperative. Once the Coop is established and gains financial support, it will provide financial and technical assistance to help better manage these areas.