We’re big fans of trees, and in parallel to our attempts to restore habitat with indigenous plants, we’ve also worked to establish a number of woodland plantings managed for firewood, timber and other uses. In the spirit of permaculture, these woodlots are designed to serve a number of functions.
Woodlot #1: Flat-topped Yate (Eucalyptus occidentalis)
The spot: This patch of the farm, a shelterbelt running along our boundary, rejected our first attempts at planting locally indigenous species. Compacted, grey cracking clay that spends the year flipping between waterlogged and baked hard, it seemed a pretty hostile environment so, after some research we thought we’d try Eucalyptus occidentalis, from Western Australia. The woodlot is located to provide shade and shelter from western winds.
Eucalyptus occidentalis, or oxies as we affectionately call them, caught our attention for a number of reasons:
- They’re well adapted to heavy clay soil
- They tolerate seasonally dry sites (preferred rainfall is 450-750mm, according to Dean Nicolle)
- They’re fast growing
- They have a lignotuber, so can be coppiced (cut and regrown)
- They produce hard and strong wood, suitable for firewood
- They are a good nectar source in autumn
- They tolerate salinity
- Jeff Nugent and Julia Boniface in Permaculture Plants reckon they produce “high quality timber” for “use in construction and for products requiring heavy and strong wood”
- They tend to be competitive for surface moisture, reducing grass cover and potentially acting as a fire break
- There are rumours they can be tapped for sugar
Planting and preparation: We planted a handful of seedlings, on contour, in winter 2015, and they thrived, so over subsequent years we have expanded the woodlot with consistent success. The ground is not prepared in any special way, we measure the contours with an A-frame (although this becomes more haphazard as the day wears on), then mattock some holes and plant them at 3 metre spacings, with 3 metres between rows. The intention is that the density of the planting will promote upright growth as they compete for sunlight. We protect them with corflute guards for humidity, and mallee mesh for kangaroo protection.
All seedlings were sourced from State Flora, including 100 or so from their discount bin! After 5 years of growth the oldest plantings are well established, standing 3-4 metres tall with some excellent upright growth in the protected centre of the woodlot.
Woodlot #2: Sugar gum (Eucalyptus cladocalyx)
The spot: Once again, grey cracking clay, but this time on a ridge adjacent to a main road. The paddock is dominated by weedy growth, primarily wild turnip (Rapistrum rugosum) and variegated thistle (Silybum marianum). Once again, locally indigenous species didn’t seem very interested in growing here, so we once again thought we trial something from further afield: Sugar gum (Eucalyptus cladocalyx), the three subspecies of which naturally occur on South Australia’s Eyre Peninsula, Flinders Ranges and Kangaroo Island. This woodlot is intended to screen from the road and provide protection from summer winds.
Eucalyptus cladocalyx met our criteria for a number of reasons:
- Tolerates dry environments (400-800mm rainfall, according to Dean Nicolle)
- Produces hard, durable timber for construction and fencing
- Suitable for firewood
- Typically grows tall and straight (provided the right subspecies is selected)
- Suitable for honey production
Planting and preparation: After several years of failed plantings in the same location, in winter 2017 we planted Eucalyptus cladocalyx on contour, but this time with a generous berm of “dump” mulch (cheap mulch of partially composted garden waste and wood chips, delivered by the truckload from the local dump) along the contour. Trees were planted at 3 metre spacings, with contours usually 3 metres apart. This berm holds moisture and excludes weeds from the immediate root zone. The seedlings were planted with our usual hand-tool methods, and protected with corflute and mallee mesh. Seedlings in the first year were sourced from State Flora, with subsequent plantings grown ourselves from seed sourced from Nindethana.
Weed control: The mulch berm method is effective in excluding weeds from the root zone of the trees for several years and this has been our primary method of control, with periodic and carefully timed slashing to promote grass growth. However, as time has gone on, we’ve begun to consider our relationship with the weeds more closely. It turns out that turnip weed has many merits, but relevant to a woodlot, we’ve discovered that its thick and vigorous spring growth actually hides the plants from kangaroo browsing, who, like us, prefer not to push through a tangled jungle of vegetation. Likewise, for an exposed site, the turnip weed provides wind protection for the growing seedlings and perhaps even creates some competition for light for the young seedlings encouraging straight, vertical growth. We manage the weeds through selective summer slashing for fire prevention and access, but over time, as the woodlot establishes we hope that the growing trees will reduce the dominance of the weeds through competition and shading.
The oldest trees in this planting are now about four years old and growing strongly. Survival continues to be patchy in some areas, so replanting sections will continue for a few years.
Woodlot #3: Mixed silvopasture
The spot: At the back end of the farm, on a grey-cracking clay slope with a variable pasture. We’ve considered planting out this paddock for some time as it sits above some significant erosion areas. We’re inspired by the concept of silvopasture, integrating forestry and managed grazing for the benefit of both, as well as its significant potential to drawdown carbon. We thought this paddock would be a good spot to trial this concept with a variety of native timber species, as well as fodder plants like saltbush. We tried to select tree species that would also allow pasture to continue to grow underneath.
The species we chose, and grew from seed for phase 1 were:
Broughton willow (Acacia salicina)
- Adapted to grey cracking clays
- Adapted to rainfall 150-500mm
- Tolerates salinity
- Timber suitable for firewood or specialty use (according to Neville Bonney, it “could rival blackwood in its qualities in cabinet and furniture making”).
Drooping sheoak (Allocasuarina verticillata)
- Locally indigenous species
- We like the sound of the wind in the needles
- Excellent firewood or craft timber
- The cones are a preferred food of black cockatoos, including Kangaroo Island’s endangered glossies
Spotted gum (Corymbia maculata)
- Fast growing
- Tall, straight timber tree suitable for construction, flooring, furniture and tool handles
- Suitable for honey production
Western white gum (Eucalyptus argophloia)
- Prefers clay soils
- Has a tall, straight trunk
- Hard, strong and durable timber suitable for construction
Planting and preparation: In winter 2019 we planted some initial trial plantings on contour. We grew all of the seedlings from seed sourced from Nindethana. The ultimate intention is to have three rows of each species, planted about 3 metres apart, separated by contour plantings of forage saltbush amid the pasture. We planted with hand tools and gave each a bucket or so compost. This time we protected the seedlings with 90cm corflute tree guards. The tree guards were appealing for their reduced cost and increased shelter from the wind. They promoted excellent initial growth, but to our dismay were not UV-stabilised and after about 9 months began to self destruct into micro-plastic dust.
As the tree guards failed, the roos moved in. After about a year of picking plastic out of the grass, we revisited this area and were pleasantly surprised by the survival rate! All of the species selected have a good number of survivors and we’ve begun to systematically replace the remnants of the tree guards with wire mesh. In 2021, we’ll be returning to this woodlot for another go. We’ll start at the top, and work slowly down the hill over several years, planting fast-growing Old Man Saltbush (Atriplex nummalaria) on contour for fodder and shelter while we replace or fill in gaps in the timber species. We’ve developed this shortlist of species that we’re interested in trialling over time in this location and others around the farm.
We always have more plans than realistically possible, and despite disheartening moments, missteps and failures, there are few things more satisfying than seeing a tree nurtured from a tiny seed thrive. We’ve learnt a lot and continue to learn how to do things at the right pace! We’re grateful, as always, for the support of our patient and persistent community of tree-planters and supporters.