How to Grow an Avocado Tree in Australia

Getting to Know an Avocado Tree

Persea americana, or avocados are a great source of healthy fats and proteins, packed into a rich, creamy green flesh, with a large smooth central pit, coated in a wrinkled black skin.

The fruits grow on large-leaved tender evergreen trees that can grow up to 6m tall, with grey-brown bark. Grown in open space in the ground, avocado trees reach spreads of up to 6m with beautiful umbrella-shaped canopies of long, wide, waxy leaves. 

As the fruits ripen, they turn from yellow to green, to dark green, and ripen further after picking to a dark black as the flesh softens.

Natural Habitat of Persea americana

Avocados grow naturally throughout Central and South America where they are native, in every climate they have, from tropical, subtropical, arid, and mountainous regions. The only conditions that Avocados can’t tolerate are cold and damp, or frost. 

For growers in Australia, that means that Avocados can be grown easily outdoors or in greenhouses wherever you live. In colder regions, they will need protection from frost or wet winters, but will still grow happily in summer temperatures outdoors.

Growing Avocado Trees in Australia

Avocados are slow to set fruit, and while there are some reported anomalies of avocados fruiting in their first or second year, it is much more likely to see avocado trees taking ten years or more to produce their first fruit. 

If you plant a mature tree, the transplant shock and stunt its fruiting for three to four years, meaning that it’s still not a surefire way to get fruit right away. However, if you plant a ten-year-old tree, in well-prepared compost that matches its current pH closely, with ready access to water and nutrients, you may well see avocados in your first year.

Follow the guide below to improve your chances.

Growing Avocados in Pots

If you live in cooler parts of Australia, you’ll need to grow avocados in pots, or in the greenhouse to protect them from frost over winter. Avocados in pots can be given any type of soil or compost mix as long as it’s well-drained.

I usually use a mix of compost and vermiculite, but perlite would work in the same way to add drainage and aerate the soil.

Conditions for Planting Avocado Outdoors

Use the guide below for specific preparations, but before you begin, dig a hole that’s twice the depth of your avocado tree’s root ball, and loosen the base and sides. 

Soil pH & Drainage

Avocados don’t need much in the way of soil nutrients but do appreciate a monthly liquid feed to add accessible base nutrients like nitrogen and calcium. They are, however, very sensitive to alkaline conditions, so require a more acidic soil where possible (between 5 and 7pH, 5 being slightly acidic, and 7 being neutral).

On sandy soils, add compost to the soil before you pack it back in around the roots. On clay soils, add sand to the soil before planting, and a 1” layer of grit to the base of the hole to improve drainage.

Light Levels and Temperature

Avocados grow best in full sun, with some open wind flow, but not strong winds. Their young branches aren’t strong and can snap, so protect them from gales, and try to allow light breezes which will help pollination.

The vast majority of avocados are not frost tolerant, but some trees can withstand temperatures as low as –5°C when they reach 5 years old or older.

How to Propagate Avocados

Growing avocados from seed, or cuttings, as we’ve mentioned, is a pretty slow process, but it is fun. Most avocados are actually quite fast to grow once they germinate, and can reach 2ft tall within a year on a thin, leggy stem. 

So, regardless of how you start your avocado tree, once it has rooted and is growing well in its pot, move it somewhere warm and bright to slow down vertical growth and encourage foliage and branching.

If your avocado continues to grow leggy, pinch it back to just above a lateral stem to encourage bushier growth that will thicken its trunk.

Propagating Avocados from Seed

Propagating avocados from seed is so straightforward that it often happens by accident, but there are some ways to boost your success and speed things along:

1. Start by removing the skin and flesh from a ripe avocado, and gently scrubbing with clean water.
2. Pierce the sides with three toothpicks or needles, with the slightly pointed end facing upwards, and the calloused paler coloured ring pointing down.
3. Place over the rim of a glass, so half the pit is below the rim.
4. Fill the glass to cover the base of the pit.
5. Refresh the water and clean the glass every couple of days.
6. In 1-2 months you should see clear signs of germination and fairly strong root growth.
7. When the roots are 3-4” long, and starting to fill the glass, place the pit into a small, clean, plastic pot, filled with a 50:50 mix of perlite and sieved compost.
8. Water well, and leave somewhere warm and bright until the roots emerge from the drainage holes.
9. Pot on to a bigger pot and care as normal, increasing the pot size as needed.

Propagating Avocados from Cuttings

Avocado cuttings are slightly more complicated than growing avocados from seed, but can speed up their growth significantly. Start in spring, with a healthy mature tree, and choose a vigorous new shoot, with half-opened leaves to take your cuttings from.

1. Before you cut anything, prepare your pot, compost, and rooting hormone.
2. Fill a 10cm deep plastic pot with 50% perlite and 50% compost or coco coir.
3. Tamp down to remove air pockets.
4. Dib a hole against the edge of the pot using a pen or pencil.
5. Take a 15cm cutting from a healthy new shoot.
6. Trim the base of the cutting to just below a node, and then scrape away 0.5cm of skin around the base of your cutting.
7. Dip in rooting hormone.
8. Insert the cut end into the hole in the compost.
9. Water well, and cover with a plastic bag (secured with an elastic band to trap humidity).
10. Leave your cutting somewhere bright, but away from direct light, at 15-20°C.
11. After about 3 weeks, the cutting should have rooted.
12. When the roots are emerging from drainage holes, pot it on and treat it like any other avocado tree using the guides above and below.

Caring for an Avocado Tree

Avocados are pretty simple to care for, and actually provide their own defences against disease when they are growing well. In the guide below to caring for mature and established avocado trees, we’ll run through how to get the most from your avocado tree, with surprisingly little effort.

Mulching Avocados

You can use any organic materials to mulch avocados. For winter, they appreciate any mulch to protect their roots from temperatures below 5°C. For spring and summer, and a light layer of compost or manure works well to boost their nutrients and retain soil acidity at a healthy level.

Perhaps most interestingly, you can use old avocado leaves to mulch around the base of the tree. Not only are the leaves an effective barrier against frost, but they also help to add spent nutrients back into the soil, and act as a barrier to excess moisture in all seasons, reducing the chances of root rot and waterlogging.

As avocados are shallow-rooted, they can send fibrous roots through their fallen leaves to capture nutrients before they decompose into the soil too. However, this is only really possible for older trees, and young trees will need supplementary leaf litter mulch or compost mulch for the first 10 years.

Fertiliser to Use

The key nutrients for any avocado fertiliser are nitrogen and potassium. And fish meal or fish blood and bone fertiliser will do the trick, but other organic options like liquid seaweed work too.

Perhaps the most important thing to factor in, which isn’t readily available on many fertiliser packs, is the inclusion of calcium, magnesium, and zinc, which help to protect the tree from disease and to develop stronger fruits, with thicker skins for better storage.

Water Requirements

Avocados get nearly all of the water from the first 6-8 inches of topsoil. While they can send deeper roots down in arid conditions, it is rare, so they irrigate through droughts in order to produce fruit. Aim for 2-3” of water per week, and reduce that if it rains.

To check if your avocado needs a drink, just poke your finger into the soil. If the top soil is dry, give it a drink, if there is any excess moisture left around the roots, don’t water.

For avocados in pots, this isn’t quite the case, as their roots will spiral around the container walls, so a soil hydrometer will give you a clearer indication of the water requirements.

Pruning and Repotting Avocados

Avocado trees don’t need pruning, and produce a lovely umbrella shape when left to their own devices. If you have to prune avocado trees, do it carefully. Use strong secateurs for young growth, and a tree pruning saw for mature branches. 

To prune mature avocado branches, make a small cut on the underside of the branch before cutting through from the top. This will reduce tears and produce clear cuts that are less prone to infection.

Avocado Winter Care

How to Harvest Avocados

Avocados tell you when they’re ripe, because they will simply fall from the tree. Obviously, leaving it that late is too late, and will ruin your crop, so for an abundance of reasons, it’s best to harvest avocados before they are ripe, and ripen them in a bowl. 

Ripe avocados have enough give to leave an imprint when you press their skins, but won’t store for more than a week. Harvest avocados in late summer and early autumn – January to May, as soon as their skins are dark.

Rather than pulling them from the tree, which can damage their stem and cause mould in storage, cut them with sharp secateurs and gently place them in a tray. Don’t overload avocados or stack them on top of each other as this can bruise the soft fruits.

How to Store Avocados

The only way to ensure avocados stay fresh for longer is to leave them somewhere cool and dry. Fridges tend to over-humidify the stored fruits so they will ripen faster. Slow ripening will give you longer-lasting harvests, so keep them in a cool dark cupboard.

If your avocados are ripening too slowly, keep a few in a bowl with a banana, and they should be ripe enough to eat within 48 hours.

For longer-term storage, remove avocados from their skins, keep the pits to one side (you can plant them later if you like), and store the flesh in the freezer. The high fat content means they don’t degrade and can be used for dips from the freezer for up to a year.

Avocado Pests and Diseases to Look Out For

Beetles

Red-shouldered leaf beetle (Monolepta australis) and swarming leaf beetle (Rhyparida spp.) are both common pests of avocado trees in Australia and tend to follow heavy rain, bringing fungal spores with them, which can enter the foliage when they bite into it. 

Treatment requires organic pesticides in targeted areas, and very diluted neem oil can be applied after heavy rain to deter them.

Learn more about neem oil and its types in our in-depth guide on neem oil. 

Fruit spotting bug 

Both the common fruit spotting bug (Amblypelta nitida) and the banana spotting bug (Amblypelta lutescens) are native to Australia. Their translucent, amber coloured, bodies are long and thin, with wiry black legs and long antennas. They are easy to spot, hard to get rid of.

On Avocados, they can damage the fruits, flowers, and buds of even established trees. They pierce the thin skin of young shoots, buds, and fruits, creating puckered markings. The easiest way to control them is with neem or pyrethrum sprays.

Helopeltis

The tea mosquito, cocoa mosquito, or mirid bugs (amongst many common names for Helopeltis) are slender black insects with red thoraxes, long antennas, and bright crimson legs.

They cause grey putting and mould on the avocado fruits and can ruin crops. They can be controlled through natural predation, but it’s also worth treating the area around your tree. 

Remove weeds and long grass where they reside and maintain slightly more neutral soil as they thrive in acidic conditions (however, this needs to be balanced as avocados prefer slightly acidic conditions).

Leaf roller

Homona spargotis, or the Avocado leaf roller, is found throughout Australia. The moth has a wingspan of about 3cm, with pale amber colourings and symmetrical brown markings on either side of its thorax. 

The moth’s caterpillars roll the leaves of avocados, trapping them in a cigar-like shape, held together with webbing. The shelters provide both food and shelter for the caterpillars until they are ready to emerge.

Cutting curled leaves off your tree when you spot them is the easiest way to deal with this pest.

Queensland fruit fly

Avocados are not particularly susceptible to Queensland fruit fly, but they will lay eggs under the skin of young fruit. The fruit is then infested with larvae and will develop noticeable cracks where the eggs were laid. You can add fruit fly traps to your avocado tree to reduce the chances of infestation.

Anthracnose

Anthracnose is uncommon on Avocados in Australia, and while the fruit will look bad, and have a bitter taste around the infection, it is still safe to eat the remaining parts of the fruit.

The infection is caused by a fungus called Colletotrichum gloeosporioides, and will affect the entire tree in time. You can help your tree to recover from infection though, by adding copper fungicides to foliar sprays, or copper additives and calcium to the soil

Cercospora spot

Cercospora spot affects the leaves and fruit of avocados, causing brown indentations that tender the fruit inedible. The Cercospora purpurea fungus that causes the spots can be treated with most standard fungicides, but the affected fruit and leaves should be removed and burned to stop cross infection.

Phellinus noxious root rot

Phellinus noxious root rot, or brown root rot disease, is a horrible disease to come across on your avocado tree. At present, there is no common cure for the disease, and it will require full removal of the tree and its roots as the infection can spread to other plants in the garden, not just avocados.

Signs of Pehllinus noxious root rot are anaemic leaves, rapid defoliation, and branch dieback.

Phytophthora root rot

If you find Phytophtora root rot causes browning of leaf tips, followed by defoliation and fading branches. The roots will be thin and break easily in your hand when dug from the ground.

Thankfully, it is actually treatable. You’ll need a chemical fungicidal treatment for the soil, such as Phosphonate, which can be added when you spot the infection, and as an annual preventative treatment.

Stem end rot

Stem end rot won’t affect your tree, and is usually caused by improper harvesting, rather than any specific fungus. If you pull, rather than cut your avocados, the tip of the fruit, where the tip meets the stem will become bruised and can allow existing funguses to enter, causing brown rot inside the fruit.

Avocado Tree Frequently Asked Questions

Are avocados easy to grow?

Avocados, while slow, are incredibly easy to grow. They are drought-tolerant, and cope well with accidental overwatering. They require minimal fertiliser, and germinate with ease. For anyone looking to make thrifty additions to the garden, avocados and an easy place to start.

Do you need two avocado trees to get fruit?

Avocado trees are self-fertile so you don’t need two trees to get fruit. One avocado tree will self-pollinate, but it does need wind and pollinators to do the work for it, so planting pollinator-friendly plants near your avocado is important. 

What is the lifespan of an avocado tree?

Avocado trees can live for well over 200 years, with some reports of avocado trees in South America being over 400 years old, and still producing.

Will a potted avocado tree bear fruit?

Potted avocados are limited in their growth, and therefore in their fruiting ability, but they will still bear fruit eventually. Their trunk needs to reach at least 2” before it will reliably produce fruit, and this can take over ten years.

Are coffee grounds good for avocado trees?

Coffee grounds are a good way to boost acidity in your soil, as well as add nitrogen. They break down quickly, and help to balance your soil nutrients. The light acidity also supports avocado roots in the uptake of nutrients.

How do I keep rats out of my avocado tree?

Avocado trees are incredibly attractive to pests when their fruit begin to ripen as they are a great source of natural fats. To keep rats and other pests out of your avocado tree, wrap a plastic collar around the trunk and slather it with Vaseline. You can do the same with any flat surface wrapped around the trunk as a collar.

Do avocado trees stop growing in winter?

Avocado trees grow through any warm months, so in warmer parts of Australia, they will not have a dormant season. In cooler parts of the country, they will hold their leaves but lose vigour for two months in winter.

Can avocado trees grow indoors?

Avocado trees grow well indoors, and with regular watering, and repotting every two years they can thrive with the additional attention. Growing avocado trees in containers indoors will slow their growth, but they will be happy for as long as you can manage their size.

Can avocado trees grow on balconies?

Avocado trees grow really well on balconies, and the slightly elevated wind can increase pollination rates. Over time, they can grow excessively tall, but can be pruned carefully to control their size.

Should I cut brown leaves off my avocado tree?

If your avocado tree has brown leaves due to over or underwatering, or as a result of fungal infection, it is best to remove the brown leaves. They can spread infection, or cause it, and will not recover.

Do avocado trees clean the air?

Mature avocado trees are capable of producing over 250 lb of oxygen every year. Young plants produce less but are still worth adding to your home to improve oxygen levels alongside other air-purifying and oxygenating plants.

How deep do avocado roots go?

Avocado trees are shallow-rooted and rarely root below the surface layer of soil. Their deepest feeding roots are usually within 6 inches of the surface soil.