Category Archives: Plantations

Pruning blackwood

Here’s a couple of blackwood pruning questions from David in South Gippsland, Victoria.

Example 1

How would you tackle this one?


That’s an easy one David!

Read the Blackwood Growers Handbook Pages 55-60.

You have at least 2 clear options on this tree – the dominant on the left or the dominant on the right.

Blackwoods have an amazing ability to straighten up if you encourage them with good pruning.

Be brave!

PS. I should mention that Spring is the time to prune blackwoods. This gives the trees a whole growing season to begin healing the pruning wounds.

Example 2:

I think a deer might have got at this one


Looks like it!

The tree is fundamentally compromised from a quality wood production point of view.

I think with this one I would prune it to ground level and let the blackwood coppice. Then after a year select the best coppice shoot.

Try and get some venison sausages!!


Notes on West coast (NZ) blackwoods


New Zealand blackwood grower and co-author of the blackwood growers handbook Ian Brown has posted a useful and detailed update on his view of current blackwood management. It makes for thoughtful reading for current and prospective blackwood growers.

Here’s the handbook: handbook

Here’s the update:

I have two comments on Ian’s notes:

Firstly on the issue of blackwood growth rate and wood quality.

Certainly current research shows that growth rate has little to no impact on blackwood wood quality in terms of heartwood colour and basic density.

But my PhD research showed that blackwood wood quality can vary enormously from tree to tree. This is supported by numerous other studies, and is shown to be mostly genetically based.

So if you want good quality wood from plantation blackwood you need to plant good quality genetic stock.

Unfortunately we don’t yet have a blackwood selection and breeding program.

Fortunately the incidence of poor wood quality genes is relatively low.

Also note that research shows there is no correlation between heartwood colour and wood basic density.

Secondly on the issue of pruning height.

Pruning height will obviously affect the final value of the crop and in a big way since most of the value is in the clear pruned log.

Where the site dictates that you can only prune to 4 metres so be it.

But a fully stocked blackwood plantation of 200 trees with an average tree diameter of 60cm dbh pruned to 6 metres will have approximately 300 cubic metres of clear grade premium blackwood per hectare. Only prune to 4 metres and the volume of clear grade blackwood comes down to 215 cubic metres per hectare a reduction of 28%!!

Whilst you have the trees growing you may as well get the most value out of them that you can.

Thanks to Ian Brown for posting his comments.

Milling blackwood in the Marlborough Sounds, New Zealand

The latest edition of New Zealand Tree Grower produced by the New Zealand Farm Forestry Association, contains a nice article by blackwood grower and sawmiller Paul Millen (NZTG 38(1) p. 7-8).

Paul runs a business called Marlborough Timbers.

Here’s the story in summary:

  • 8 plantation blackwood trees milled
  • Tree age: 30 years
  • Tree dbh: 30 – 60cm
  • Pruned height: 4 – 6m
  • Total log volume: 10 cubic metres
  • Total sawn recovery: 4.0 cubic metres
  • Total sawn recovery: 40%
  • Three to four logs per tree were milled, at lengths between 2.4 metres and 3.6 metres, including unpruned logs from above the pruning lift that were targeted to produce decorative knotty flooring.
  • Knotty boards were rough sawn 157 x 27mm and sold green at $NZ1800 per cubic metre. In future they hope to sell this grade of knotty blackwood for $NZ2,500 green or $NZ3,000 kiln dried.
  • They hope to sell kiln dried clear (select) grade blackwood for $NZ4,000 per cubic metre, which equates with what Malcolm Mackenzie is selling select grade blackwood into the NZ market:

Here’s a link to the article (pdf file):

Milling blackwood in the Marlborough Sounds NZTG 38-1

I got the extra information from Paul to help fill out the story.

Blackwood is a niche timber that I suggest is like the pinot noir variety of New Zealand exotic timbers. The timber has some incredible colour and diversity, and it is a relatively easy hardwood to saw and season. There is a lot of satisfaction in producing a really top notch product. I know there is some excellent mature well-managed farm forestry stands and these growers deserve to receive a high return given the demanding silviculture required to manage these early plantations.

Maybe the New Zealanders should market blackwood as Noirwood!!

As more of the New Zealand farm-grown blackwood resource matures we will be seeing more of these success stories.

Thanks to Paul Millen for the story and further information.

Bold plan to breathe new life into SW timber industry


SW? As in south west Western Australia!

Just like the rest of Australia the logging of public native forests in south west Western Australia has been a battle ground for decades, with the forest industry now on its last legs needing continuous Government support.

The local forest conservation group the Western Australian Forest Alliance has come up with a plan to rebuild the forest industry and create jobs. The Plan is called Forests for Life.

Normally I would be a bit sceptical of any industry plan developed by environmentalists, and from my reading the FFL plan certainly has some weaknesses.

What I do like though is that the broader community are getting behind the Plan, including the local Augusta/Margaret River Council.

Here at last is the community taking the lead, showing initiative, adopting a positive attitude and working together.

This I like!!

The question now is will the forest industry and the WA State government get behind and support the Plan. The Western Australian Farmers Federation also needs to be brought on board to help give the Plan some economic credibility and community support.

I’ve already seen the potential for growing Tasmanian blackwood in SW Western Australia:

Imagine this happening here in Tasmania?

Carrabin first inventory


A few months back I had the opportunity to do the first inventory measurement of the Carrabin blackwood plantation.

You can read about this plantation in my previous blogs including the major thinning in 2013:

The plantation is now 16 years old and 3 years since its major thinning.

There are still about 20 trees to be removed before the plantation reaches its final stocking of approximately 36 trees. The above picture shows recent thinning in progress.

In all 39 trees were marked and measured. Here are the results:

Carrabin Table

Note that the objective is to grow blackwood trees that have single straight stems pruned to at least 6.0 metres, and a breast height diametre (DBHOB) of 60cm when harvested.

Because of the close initial planting (2x2m) and the delayed thinning, the remaining trees do not have the diameter I would expect for this age. The largest trees are 27 cm diameter.

As these trees rebuild their crowns following the 2013 thinning I expect the diameter growth rate to increase. Another inventory in 5 years will tell us whether this has happened.

This blackwood plantation is a real credit to the commitment and dedication of the owner.

This is how the special timbers industry should be in Tasmania. Not a politically motivated taxpayer-funded junket into our last remaining public old growth forests.



Plantation blackwood resonator guitar


Wellington, New Zealand-based luthier Paddy Burgin has created another beautiful musical instrument using plantation-grown blackwood.

Made for a local (NZ) steel player who wanted an instrument made totally from NZ grown woods. Paddy’s plantation-grown blackwood comes from Golden Bay at the northern tip of New Zealand’s south island. The tree was about 35 years old when harvested.

I only wish more instrument buyers and luthiers would take the plantation tonewood challenge and try plantation grown blackwood.

Great work Paddy!

Blackwood Plantation Financial Model


This is a financial model that calculates the Internal Rate of Return (IRR) from an investment in one hectare of commercial blackwood plantation. The model is setup in an Excel spreadsheet:

Blackwood financial model.xlsx

Here’s the link to find out more about the IRR function in Excel:

This model is a work in progress and is designed to encourage feedback, comment and updating.

You can download the model and use your own numbers if you wish.

Contact me if you want help modifying the model to your personal requirements.

To begin with I went back to the New Zealand Blackwood Growers Handbook that contains an financial model on page 77. I set this model up in a spreadsheet and came up with the same values as shown in the handbook. handbook

I then modified the model according to my own recommended simplified plantation regime. This simplified plantation regime reduces the initial establishment and management costs, and reduces the workload required in the first 10 years.

I also changed some of the values in the model to better reflect what I consider are current costs.


  • A 35 year rotation length;
  • In 35 years time there will still be a high demand for quality appearance-grade timbers. Technology is rapidly changing many timber markets, including construction-grade timbers, but I think there will always be a demand for premium solid appearance-grade timbers;
  • The objective is to grow the plantation to an average stem dbh of 60 cm, with all trees pruned to 6.2 metres. This should produce approx 300 cubic metres of premium blackwood sawlog;
  • The plantation is established on a site suitable for growing commercial blackwood;
  • The land is already owned (ie. no land purchase costs are included). But go right ahead and add land costs and see what it does to the investment;
  • The simplified plantation regime is used planting 200 blackwoods per hectare;
  • One of the largest costs in blackwood plantations is protection/fencing to protect the trees whilst they are young. Blackwoods are highly palatable to a wide range of domestic and wild herbivores, so good protection is essential. Protection costs will vary considerably according to plantation size, shape and location/terrain.
  • Annual weed control (spot spraying) is essential whilst the trees are becoming established. Blackwoods do not like competing against heavy grass/weed cover. After 5 years I have included a general weed control (slashing) every 5 years for general maintenance. By about age 20 years the blackwoods should have the site under control with little need for ongoing weed management.
  • Actual costs will vary according to individual circumstances. Most of the costs are my best guesses. If anyone has some real data to contribute that would be appreciated;
  • No harvesting or transport costs are included;
  • Other costs can be included fairly readily, such as rates and other overheads, and management costs;
  • The sawlog price is my current best guess at a competitive market price for a large parcel of quality blackwood sawlogs. For example the December 2015 Hydrowood log tender had 14 quality blackwood logs sell for an average of $625 per cubic metre.


The model shows an internal rate of return on Tasmanian blackwood plantation investment of around 10% over 35 years.

For a 35 year investment that is a decent return. Fixed term deposits are currently offering around 3.00% over 4 years (updated Feb 2016).

If a very good site is planted and hence the rotation shortened to 30 years the return on investment increases to 12%. Alternatively if the value of the plantation after 35 years is only $100,000 per hectare the rate of return is still 9%.

In other words the investment is quite robust to changes in conditions and markets.

Commercial blackwood plantations are a profitable investment under current market conditions.

I wouldn’t recommend buying land just to grow commercial blackwood. Blackwood is not a broad-acre crop but requires certain site characteristics to grow successfully.

Many Tasmanian farms have areas that are currently underperforming or neglected; covered in weeds, bracken and blackberries. These areas are not contributing to farm income, but many of these areas are suitable for growing commercial blackwood.

If a farm has a number of these areas, the investment and the workload can be spaced over time, for example by planting an area every 5 years. After 35 years a set of periodic incomes is achieved from regular harvesting and replanting of plantation blackwood.

Now the one major feature missing in the forest industry is greater market and price transparency to help encourage this investment.