Growing firewood in South Australia
Firewood is in high demand, with nearly a quarter of Australian homes using it as an energy source.
A firewood enterprise offers landowners the benefits of sustainable landscape management. Compared to sawlog production, it also:
- utilises sites of lower productivity
- generates faster income
- reduces the need for pruning and thinning
- lowers establishment costs through the selection of coppicing species, instead of replanting
- adds value through harvesting and marketing.
Consider the following uncertainties and market risks of establishing a firewood enterprise.
Supply and growth considerations
Wood is an effective, renewable fuel when burnt efficiently. Educating firewood buyers about using efficient burning systems and operating slow combustion heaters can help prevent air pollution.
To minimise wood smoke, merchants also adhere to the Voluntary Code of Practice for Commercial Firewood Suppliers. This encourages sale of well-seasoned wood that is grown on plantations, with ideal burning characteristics.
Selecting an appropriate firewood plantation regime will depend on the site and aims of the tree grower.
Woodlot options
Woodlot options
Firewood specific woodlots
Plantings are established specifically to grow firewood.
Integrated firewood and sawlog production
Trees are principally planted for sawlog production. The woodlot is thinned to remove the trees of poor size and form, when they are large enough for firewood.
Care is essential to avoid damaging potentially high-value sawlogs produced from the remaining trees.
Low intensity direct seeded woodlots
This system uses local species established by direct seeding. In addition to producing a firewood crop, it satisfies conservation and provides shade and shelter value.
It is suited to the supply of personal firewood or large, low yielding plantings in lower rainfall situations. In higher rainfall zones, these woodlots allow large areas to be established at lower cost than planting seedlings.
Species and site selection
These tree characteristics are needed for effective firewood:
- quick growing
- coppicing ability
- producing dense wood
- easily split
- slow and steady burning with minimal ash production.
The following species have the most potential for plantation production, as firewood and for other uses.
Burning attributes and commercial uses
Burning attributes and commercial uses
| Species | Burning attributes | Other potential uses | |||
|---|---|---|---|---|---|
| Splitting | Ignition | Coaling | Sparks | ||
| Sugar gum (Eucalyptus cladocalyx) | Difficult | Poor | Excellent | Few | Panelling, heavy construction, building framing, decking, internal flooring |
| Swamp yate (Eucalyptus occidentalis) | Difficult | Poor | Excellent | Few | Fencing posts and poles, heavy construction |
| South Australian blue gum (Eucalyptus leucoxylon) | Difficult | Poor | Excellent | Few | Fencing posts and poles |
| Early black wattle (Acacia decurrens) Late black wattle | Excellent | Excellent | Good | Few | Tanning bark, fencing posts and poles |
| River red gum (Eucalyptus camaldulensis) | Difficult | Poor | Excellent | Moderate | Furniture, bench tops, fencing posts and poles, heavy construction, internal flooring |
| River she-oak (Casuarina cunninghamianai) | Good | Poor | Excellent | Few | Furniture, panelling, fencing posts and poles |
| Tasmanian bluegum (Eucalyptus globulus) | Fair | Fair | Good | Few | Fencing posts and poles, building framing, internal flooring, woodchips |
| Silver wattle (Acacia dealbata) | Excellent | Excellent | Good | Few | Panelling, furniture, veneers |
Site conditions directly affect the quality of trees grown. Deeper, moist soils are recommended as they support faster growing trees.
Learn about tree growth attributes and site requirements for farm-based forestry.
Establishment
Firewood is best grown in woodlots or belts of trees, at least 6 rows wide. The planting density should be:
- 800 to 1400 trees per ha, if average annual rainfall is greater than 600 mm
- 400 to 800 trees per ha on sites with lower rainfall.
Learn about ordering seedlings and planting trees, including storage and stocking rates.
Coppicing
Managing a coppice crop saves on the cost of seedlings, but it is labour intensive. Coppice growth should reach 60 cm in height before thinning, or it can be left un-thinned which produces a more uneven crop.
Stumps should be cut:
- to a height of half their diameter for firmness in the wind
- on an angle to avoid water ponding.
Coppice regrowth is likely to reach harvestable size 10% quicker, but the ability to coppice declines as stumps age.
Harvesting
In areas receiving greater than 600 mm rainfall, fast growing tree species are likely to be harvested in 10 to 15 years. This is based on:
- tree size
- market demand
- the timing of other farming operations.
Firewood specific woodlots are clearfelled, while selective felling is used in integrated firewood and sawlog production. Row felling is needed if firewood production is combined with biodiversity conservation, soil management, or for habitat purposes.
Landowners should consider a commercial forest plantation licence to secure their forest property rights and harvest security provisions.
Firewood harvesting activities
Firewood harvesting activities
A firewood operation can be broken down as follows:
Tree felling and delimbing
Trees are felled, then the branches and heads are removed to create a bare log. The leaf and branch litter are best left on site to return nutrients for the next crop.
Extraction
Whole stems are taken out of the plantation to an adjacent area, before being crosscut into shorter lengths. Cutting can also occur within the forest before removal.
Crosscutting
Crosscutting green wood is easier than cutting dry wood. Short firewood billets of 30 cm lengths are recommended to dry faster.
Many commercial firewood processing machines crosscut and split the timber in the same operation.
Stockpiling for drying
Firewood must be sold by weight with an internal moisture content of less than 25%. Drying times of newly processed firewood are affected by:
- tree species and age
- diameter
- percentage of heartwood
- exposure to temperature and wind while curing.
Wood with small diameters and little heartwood need harvesting at least 6 months prior to anticipated use. Older, slower grown timber with more heartwood could take 12 months or more to dry.
To minimise fungal growth, dry your processed firewood in small, partly covered stacks, raised off the ground and exposed to airflow.
Splitting
Dry wood is easier to split than green wood, so this process is traditionally combined with loading to reduce double handling. However,
modern processing machines may crosscut and split logs at once while still green.
Loading and transport
Small scale operations are loaded by hand to separate wood from unwanted bark. Larger operators use a conveyor belt loading
system and stack the wood to reduce transport costs.
Marketing
The following marketing options exist for firewood growers:
- Sell the standing crop to a harvester or merchant. This offers the least amount of work but the lowest return. Sale price depends on the volume to be harvested and the ease of harvesting.
- Harvest and transport yourself, then sell to merchant. This option is profitable but labour intensive, with high machinery costs. Most merchants require delivery by the truck load (10 or 20 tonnes) and the wood to be:
- dry and cut to length
- split where necessary
- free of bark.
- Harvest and retail yourself. This approach maximises value and the returns depend on the travel distance. Firewood is sold in lots of under 4 tonnes and delivered to households. This overcomes the need for heavy transport equipment, but a weighbridge ticket is required.
Contact
PIRSA Forestry
Email: pirsa.forestry@sa.gov.au
