Ordering seedlings and planting trees
Following best practice procedures to plant your trees helps to avoid:
- conducting extra weed control
- replanting
- delaying thinning and harvesting due to poor growth.
Planning ahead will minimise long-term costs and efforts of maintaining the plantation.
Ordering seedlings
Learn how to select an appropriate tree species for either:
It is necessary to order trees by December the year before planting, when most nurseries sow their seeds and set cuttings.
Source seedlings grown from high quality seed, or cuttings from select plants. This gives your plantation the best available genetics for wood properties and fast, even growth.
Minor seedling deaths may still occur, so consider ordering 5% extra to refill losses before the end of September, in the year of planting.
Transportation
Eucalypt and pine seedlings are available in containers. Pines may also be available as bare-rooted stock which are transported in bundles of 150 to 200, wrapped in hessian or plastic with their tops exposed to the air.
Plants are delivered from nurseries by a freight service or picked up by the forest grower. They should be kept out of direct sunlight and wind during transit.
On arrival plants should be inspected to ensure they are healthy and have good root development.
Storage
Follow the below steps when you receive new seedlings.
Container-grown seedlings
Container-grown seedlings
- Store your seedlings in a protected area and cover with chicken mesh, at least 50 cm above the tips and well supported by sturdy posts. This allows light to reach the seedlings while protecting them from browsing wildlife.
- Make sure seedling trays are not resting directly on the ground to avoid tree roots taking hold in the soil.
- Apply snail bait around young eucalypt seedlings.
- Water seedlings regularly through the week and more often during windy conditions to prevent them from drying out.
Bare-rooted pines
Bare-rooted pines
Handle packs gently to avoid damaging the root systems and needles. You can either store these plants for a few days, or just over a week:
- Place seedlings out of direct sunlight and wind. Keep the packs moist and plant the trees within 4 days to avoid decomposition.
- Dig a trench in a shady position. Remove trees from packs and place in a line approximately 3 trees thick. Back fill with dirt, covering about 5 centimetres up the needles. Make sure the soil is kept moist and plant within 10 days to avoid them taking root.
Planting trees
In South Australia, planting takes place between June and August when there is sufficient soil moisture. This depends on the timing of opening rains and any applications of residual herbicides – check the top 30 cm of soil for dampness.
Immediately prior to planting, water each tray of seedlings by submerging completely in water until all the air bubbles disappear.
Plant seedlings deep enough so that the soil plug is completely covered and protected from the environment. Correctly planted trees should not be easily pulled out.
Tools
Eucalypt seedlings are planted using a tool such as a Pottiputki, with seedlings carried in a kidney tray. If large cracks and air pockets are present in the soil, use a border spade instead. One person can plant up to 3000 trees a day with these tools.
For bare-rooted seedlings or cuttings, use a border spade and a planting bag. Around 1500 trees can be planted by one person in a day on a second rotation site, and about 3000 seedlings on a first rotation site.
Border spade technique
Border spade technique
- Open a hole large enough to take the seedling roots.
- Place the seedling deep in the hole and lift it slightly so that the roots are not curled up in a ‘J’ or distorted. About 5 centimetres of the seedling stem should be under the soil.
- Firm the roots at the bottom of the hole by driving the planting spade in alongside the hole, then pushing in the soil to cover the hole and levering it closed. Make sure there are no air pockets around the roots.
- Compress the soil around the seedling by firming with the foot on one or both sides.
Stocking
Plantation forests are established in rows. The inter-row distance and direction of rows must allow for vehicle access during site preparation, weed control, thinning, and harvesting.
The density (stocking) of trees planted influences the:
- growth rate
- trunk structure
- size of branches
- knots in wood
- type and volume of wood products that can be harvested, (e.g. pulp wood, sawlog, or firewood).
Tasmanian bluegum is planted at 1000 trees per ha – space trees 4 metres (m) between rows and 2.5 m between trees.
Radiata pine is planted between 1300 and 1600 trees per ha – space trees 2.5 m between rows and 2.5 m between trees, or 3 m between rows and 2.1 m between trees.
Sites with an annual rainfall below 600 millimetres are usually spaced further apart.
Replanting
The suggested stocking rates allow for a 5 to 10% loss due to animal browsing and other causes. It also accounts for natural variability, as even the best genetic material will produce seedlings that vary in growth and form.
If seedling survival is less than 85%, refilling can be conducted after the second year weed control, where there is a gap of 2 or more trees within a row.
Contact
PIRSA Forestry
Email: pirsa.forestry@sa.gov.au
