Check that the tree is free of pests and diseases before buying. The tree should be growing actively (except those species which have a dormant growth period). Leaves should have a healthy green colour typical of the species. Stems should be sturdy and vigorous. This vigour will show even on dormant plants.
Avoid a tree that has obviously been potted for a long time. Under these conditions the tree is often root bound and growth has become weak. This tree often takes a long time to commence regrowth after planting out. Because the root system was constricted in the pot the tree may develop a poor root system in the ground and be prone to fall over in wet windy weather.
A smaller vigorously growing tree is generally a better proposition than a more advanced one that has hardened in the pot. A small root system that is allowed to grow and spread naturally will be a better proposition than one that has been left constricted in a pot for a long time.
It is not generally a good idea to buy trees and hold them for a planting that is a long way in the future. Buy fresh and plant fresh.
Preparing the Site
With commercial plantings the soil should be deep ripped in both directions to break up any compaction in the subsoil. Ripping must be done when the soil is dry. The final ripping is always down the slope.
If time allows (3 - 6 months) apply 1 - 2 bags of animal manure to the surface of an area 2 metres in diameter at the planting site and allow it to rot away. Peanut shells, straw or bagasse may also be used but use twice the quantity.
If planting a shrub a smaller area would be treated but at the same rate of organic matter per unit of area. Do not use animal manures on native plants particularly these which occur naturally in poor soils. The increased phosphorus level can cause severe damage to many of these species.
Digging the Hole
The planting hole needs only to be large enough to hold the new plant plus sufficient room to be able to firm the soil around the plant.
If a post hole digger has been used to form the planting hole check that the twisting action of the digger has not glazed the wall of the hole. A glazed surface will constrict root growth. If necessary break the wall of the hole away with a spade or crowbar.
Digging a hole in wet soil with a spade can also produce a glazed wall particularly if the spade has been moved back and forth against the remaining soil. In this case also, the edge of the hole may need to be broken up.
Do not dig a large hole and fill with a different type of soil material except perhaps in a sandy soil. Using a different soil type to fill a hole in a clay soil will make a pond in the wet season and drown the tree. Water does not move freely across the join line of the two soil types and drainage is seriously impaired.
If fertilizer is to be added put some in the base of the hole and cover with 75 - 100 mm of soil. Spread the remainder over the soil removed to form the hole and stir in. It is again mixed as the hole is filled.
Tree Height After Planting
After the tree has been planted and the soil has settled the top of the soil from the pot should be at ground level. Grafts, e.g. in citrus, should be 75 - 100 mm clear of the soil. Nor should the soil have sunk to form a dish which will hold water in the wet season.
On the wet tropical coast where rainfall is high it is a useful precaution on the heavier, poorer drained soils to build a mound 75 - 100 mm above normal soil level at the planting site before the hole is dug. After the tree is planted and the soil has settled there will always be a slight mound to prevent water lying at the base of the tree.
The potted plant is brought to the planting site and gently tapped out of the container or else the container is cut away.
If the roots are constricted gently spread them before putting in the hole.
Half fill the hole with soil and compress the soil firmly but gently. A pole about the size of a hoe handle may be used to firmly pack the soil. If the soil is not firmed well holes may form as the soil settles, allowing the roots to dry or preventing roots from actively growing out into surrounding soil.
Complete the filling of the hole and firm again. Make a shallow dish around the tree about 500 mm in diameter and water the tree thoroughly. The dish can be smoothed out when sprinkler irrigation of the tree commences.
CARE AFTER PLANTING
Staking If necessary stake and tie the tree to prevent wind whipping the tree about. Whipping can cause root damage leading to slow establishment or even tree death. The stake remains till the tree is well established - (6 - 24 months). The string may have to be retied at intervals to prevent it cutting into the trunk as the tree grows.
Mulch the soil but always leave a gap (150 - 200 mm diameter) in the mulch around the tree to allow the trunk to dry rapidly after rain or watering. Mulch lying against the bark may lead to rotting of the trunk. Mulching keeps the soil cool, holds water in the soil and restricts weed growth from competing with the tree.
Wind and Sun Protection
Some form of wind and or sun protection may be needed on the young tree. Often an old washed fertilizer bag (open at both ends) is placed over the tree. Three stakes are then used to stretch the bag away from the tree. The bag is left till it rots away.
Alternatively a bare trunk that is exposed to the sun can be painted with a lime wash or with a white plastic (water-based) paint to prevent sunburn. A young litchi is particularly subject to sunburn on exposed branches and severe sunburn can occur.
This is a very important part in establishing a tree particularly in hot dry weather. Bear in mind that until the tree makes active root growth it is only exploiting the volume of the pot for its water needs. Some moisture will move in from the surrounding soil but this would only partially overcome the need for regular waterings.
In hot weather the tree would need to be watered 2 or 3 times per week. In cooler weather 1 - 2 times per week. If in doubt feel the soil at the base of the tree to judge if watering is needed. Apply 8 - 10 litres each time.
Once the tree has made a flush of new growth, one watering every 7 days should be sufficient (assuming the trees are mulched). 1 - 1½ hours of sprinkling time.
Fertilizer Placement (includes lime or dolomite)
Do not throw the fertilizer in a concentrated band close to the base of the tree. The high concentration of salts will severely damage or even kill the tree.
In the first year fertilizer is applied evenly in a band about ¼ - ½ m wide, the inner edge of the band being 150 mm from the trunk.
As the tree gets older the width of the band increases as also does the distance away from the trunk.
At four years the band would be 1 metre wide and the centre of the band would be under the drip line (the outer edge of the canopy). Fertilizer applications are applied to the surface and watered in. Do not dig the fertilizer in as the digging will cause root damage. If 25 mm of rain has not fallen within 24 hours of a fertilizer application the tree should be thoroughly irrigated - 1- 1½ hours with a sprinkler.
Remove the tag from the trunk or branch as the tie will rapidly cut into the wood as the tree grows. If a label is necessary tie it to a small stake along side the tree or better still make up a plan of the orchard.
If the tree is grafted remove all growth forming below the graft. Other pruning will vary depending on the type of tree and is discussed in the leaflet for that tree.
DATE: January 1992
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