Site and soil
Site selection is of prime importance, choose a sunny spot, a distance away from other trees, with deep and well drained soil.
Avocado trees are highly susceptible to both water logging and Phytophthora root rot disease, any practice that will improve the soils drainage rate can make all the difference with your successful avocado growing. Add base fertilizers (lime, gypsum, phosphate) if needed.
Planting
Avocado trees respond very well to heat, with warm soils promoting optimal root growth. For this reason, we recommend planting between mid October and mid March. Planting outside these periods is possible but extra care to protect from frosting and maintaining leaf quality is necessary.
Ideally trees should be planted as soon as you take them home - if not ensure they don't dry out, by watering thoroughly a minimum of once per week.
Always pick up your potted tree by the bag and NEVER by the trunk.
Clear weeds away for about 1m in diameter, then dig the hole in the centre, slightly deeper and wider than the bag. No additional fertiliser or compost is required. Check that depth of the hole - place your tree in its container in the hole, the level of the soil in the container should be about 25 mm above the top of the hole.
Place a strong wooden stake firmly into the hole, about 20 cm away from where the plant will sit. Once you have the tree planted tie it to the stake. Two to three weeks after planting you might have to loosen the ties so they don't damage the trunk.
Extreme care is needed when removing the Avocado from the plastic bag as the roots of your new avocado trees are very brittle and break easily - DO NOT pull the tree out through the top of the bag! And NEVER TEASE OUT THE ROOTS of trees before planting.
Here's how to plant your tree ... take a sharp blade and cut around the base of the bag and remove it, now sit the tree (still with the bottomless bag in tact) in the hole, then slit the bag half way up both sides from the bottom up and peel the plastic upwards - cover with soil to this level - gently pressing the soil into place around the plant. Now cut the remainder of the bag and remove it completely - cover the with the top soil, gently pressing the soil into contact with the root ball from the sides towards the center. Do not tamp the soil down with your feet.
Check the depth again ... The top of the nursery potting mix should be slightly above (25 mm) the surrounding soil level - if buried too deep, this may result in collar rot and planting too shallow will expose the un-planted stem and roots to sunburn.
Protect tree with a wind break box of 1.2 meter square and 1.8 meters high. This height will allow growth for the first eighteen months. Shelter should be erected so as to also protect from rabbits and hares.
Aftercare
Watering - more trees die because of too much water than too little - they can literally drown! When we say too much we mean too often! Do not be panicked into watering because the tree is wilting during the day-the tree is simply having difficulty drawing enough water to keep itself cool. Rather examine morning or evening for a better visual indicator.
Mulch - to increase the soil organic matter, improve the soil structure, reduce evaporation and fluctuations in root temperature. Mulch can be used to cover newly exposed roots, but keep mulch away the tree trunk., In addition, granular fertilizers can be applied to the soil 40 cm around the stem, being careful to avoid contact with the stem.
Spraying - we recommend applying copper spray to protect your trees when young, and throughout winter. Nitrosol helps trees grow stronger and healthier and can be applied to the soil or applied as a foliar spray.
Weeding - to prevent competition with the avocado tree roots. Hand weed an area 1 meter diameter around the trees. Herbicides are not recommended at this stage anywhere near the root zone. Avocado feeder roots can be very close to the surface and even grow up into the mulch so don't risk exposing the tree to herbicide.
More Info
- check trees for pests - bugs to watch for are Grass Grub and Fullers Rose Weevil can which can start feeding on plants the night of planting. Also pay attention to Leaf roller Caterpillar, Thrips and Six Spotted Mites.
- protect the young trees against frosts in cooler areas.
- removing all flowers for the first 18 months is recommended to promote strong tree growth, however if trees are particularly strong (lots of vegetative growth is apparent) consider leaving the flowers and fruit on.
- in Spring check for shoots developing below the graft union and remove them.