Farm Forestry in the Adelaide Hills - Planting technique

A planting with mattock.

Planting technique:

The actual planting operation is not difficult. High mortality rates and disappointing early growth rates are usually the result of poor preparation of seedlings and poor planting technique.

Remember these key tips for successful planting:

• when you get your seedlings you must put them in a clean site where they are protected from frost and where they can be watered and keep them well watered!
• before planting give the trees a good water to ensure the potting mix is saturated. (You should also consider a dose of liquid fertiliser to help with the shock of transplanting.)
• if possible have a bath or bin of water in the field so you can dunk the seedling tray immediately before planting, which will ensure the potting mix is at field capacity when you plant the seedling
• always plant into moist soil and ensure good soil–to–root contact by removing air pockets. This will mean that you won’t have to worry about watering the seedling in
• make sure the stem of the tree is buried 2–3 cm. This places the root ball slightly deeper and provides a buffer to prevent the root ball drying out. It also provides a safety margin from any possible leaching of residual herbicides applied after planting
• if your planned planting day is unseasonably warm or there is drying wind consider waiting until conditions are cooler and less drying. The best time to plant is when rain is forecast!

Contract planting:

You can plant yourself or engage planting contractors. Naturally, contract planting costs are cheaper for “easy going” sites. Putting extra effort and cost into ensuring a well prepared site will be compensated for by the savings in planting costs. On the other hand, you will pay more per hectare for sites that have:

• shallow rocky or heavy soils
• steep slopes
• weedy sites
• difficult vehicular access
• a small area.

A general starting point for negotiating the cost of planting is half the cost of the seedlings.

Fertilising:

In most situations trees respond to fertiliser. However, if you plant your trees on an ex–pasture site with a reasonable history of fertiliser application you will probably find the growth response invoked by additional fertiliser will not warrant the added expense.

Typical fertilisers for forests are based on superphosphate and trace elements, diammonium phosphate or specially prepared “Forest mixes”. Initially it is best to place the fertiliser by hand adjacent to the tree but downhill of the tree to avoid a sudden overdose. When the trees have a closed canopy and fully occupy the site, broadacre fertilising by tractor or air is the most beneficial. You must ensure good weed control otherwise the weeds may benefit more than your trees!

Pests and diseases:

You can keep most pests and diseases at bay by maintaining the trees in a stress–free state. In young stands this includes freedom from weed competition; in older stands periodic thinning to release trees from competition. The likelihood of insect attack is difficult to predict and varies with seasonal conditions.

In all but severe infestations, you can probably leave the trees to fend for themselves assisted by beneficial birds and insects. The following table presents some of the more commonly encountered pests but you should remember that sometimes the importance of the pest depends on where the trees are grown.

For example eucalypt leaf beetles are a major problem in Tasmania and although they occur in our area they are not a problem (yet).

Similarly if species are grown in conditions they are not well adapted to the trees are more susceptible to attack, for example susceptibility to borer attack of forestry species grown in low rainfall areas.

Most likely pests to look for on the key forestry species:

Pests and diseases:

You can keep most pests and diseases at bay by maintaining the trees in a stress–free state. In young stands this includes freedom from weed competition; in older stands periodic thinning to release trees from competition. The likelihood of insect attack is difficult

Vermin:

The most prevalent pests of plantings are hares, rabbits and kangaroos. Blackwoods and casuarinas are particularly palatable and susceptible to browsing damage.

Each pest causes a different type of damage:

• rabbits eat plants back to ground level
• hares “snip off” young trees with a clean 45 degree angle cut and usually drop the top nearby
• kangaroos tend to graze back the tree tops heavily, in some cases leaving the stem though casuarinas are normally eaten to ground level.

Counter-measures:

Individual tree guards are expensive and are generally not cost–effective.

Eradicate rabbits and hares before planting and watch for subsequent damage. Hares are territorial and control will only last until another animal moves into the vacant territory.

Kangaroo–proof electric fencing can be erected but the cost is prohibitive in most instances. Generally kangaroos are not a problem if you avoid blackwoods and casuarinas and plant less palatable pine and eucalypt species.

Galahs are occasionally a problem but little can be done to control them.