If your avocado tree is in good health, it’ll boast green leaves and look vigorous.
But if those lush leaves are turning brown, it’s your tree’s way of telling you that something isn’t right.
Some common causes include underwatering, stress from extreme temperatures, and too much salt in the soil.
But don’t worry just yet — brown leaves in avocados are often fixable once you know what’s causing them.
Make a few tweaks and, fingers crossed, your avocado tree will bounce back with fresh, green growth!
What’s Causing Your Avocado Leaves to Turn Brown?
A few brown leaves on your avocado tree aren’t usually a big deal.
But if the browning is widespread, that can reduce photosynthesis and slow down fruit production.
Here are the common reasons why avocado leaves turn brown:
Below, we’ll talk about each one and share tips to fix the issue!
1. Underwatering
Sometimes, avocado tree leaves turn brown simply because they’re not getting enough water.
If your avocado tree is underwatered, the leaves may start to wilt, curl, or droop.
Soon after, you might notice leaf tip burn, which spreads to the edges. The leaves will also feel crispy to the touch.
To check, stick your finger about 5cm into the ground.
If the soil feels dry and it’s been a while since you watered your avocado tree, it’s probably dehydrated.
How to care for an underwatered avocado tree
Don’t wait too long between waterings. Once the soil dries out, give your avocado tree a good drink!
Water deeply, all the way out to the drip line (the outer edge of the canopy).
Keep in mind that you’ll need to water more often during hot weather or if the tree is in a pot.
Consider the soil type, too. Avocados need a good soil that drains well and holds just enough moisture, like sandy loam.
If your soil is too sandy, it will dry out too quickly. Meanwhile, compacted or heavy clay can prevent water from reaching the roots.
2. Sunburn
If it’s been unusually hot in the past few weeks, keep an eye out for sunburn or leaf burn on your avocado tree!
As tropical fruit trees, avocados thrive in warm weather. However, there’s such a thing as “too hot.”
When temperatures stay above 40°C for too long, the tree can suffer.
Intense sunlight can burn the leaves, and new shoots are the most vulnerable. The avocado’s branches and fruit may also look scorched.
The damage usually appears only on the side of the tree that gets the harshest sun. Meanwhile, the other side might not be as affected.
Helping an avocado tree recover from sunburn
Give your avocado tree some shade using a cloth, net, or umbrella. Cover the part that gets the most intense sunlight.
Next, water the tree more often. Do this in the early morning or late evening so the soil doesn’t dry out too fast.
You can also mulch around the base of the tree to keep the soil cool and protect the root system.
Lastly, avoid heavy pruning, especially in summer. It can make the tree more vulnerable to heat stress and sun damage!
3. Cold Damage
Avocados aren’t exactly cold hardy. Some avocado varieties can handle cold temperatures down to −5°C, but only for a short time.
If they’re exposed to frost for too long, they can show signs of damage.
You might notice the avocado leaves turning brown and curling — particularly on young leaves and new growth.
The browning often looks mottled and covers the whole leaf, not just the tip.
Avocado fruits can also develop brown patches, and branches may die back or split.
How to protect your avocado from cold damage
Young avocado plants are more likely to get damaged by the cold. You can protect them using a frost cloth or horticultural fleece.
Simply drape the cloth over the tree — make sure it covers the entire plant and reaches the ground.
If the avocado tree is very small, use hoops or stakes to hold the cloth up so it doesn’t rest directly on the leaves.
Tie the cloth down so the wind doesn’t blow it away.
For bigger trees, wrap the trunk and base with burlap to help keep them warm.
You can also grow dwarf avocado varieties (like Rincon and Wurtz) in a pot. That way, you can bring them inside during cold weather.
4. Salt Burn
Avocado leaves turning brown at the tips can be caused by salt build-up in the soil.
This is especially likely if the weather has been stable and you’ve been consistent with watering in the past few weeks.
Excess salt — particularly chloride — can accumulate in the avocado tree leaves and cause browning. This is known as chloride toxicity, or simply salt burn.
The browning often starts at the tips and edges of the avocado leaves, before it spreads inwards. The affected leaves also become brittle and may drop later.
Causes of salt burn in avocados include:
- Overfertilising
- Using water with high chloride content
- Highly saline soil in arid and coastal areas
How to treat salt burn in avocados
First, make sure that salt burn is the issue. If you’ve been using bore or tap water, it’s best to test the soil and water for salt levels.
You can grab an electrical conductivity (EC) metre from a garden centre to test the soil. EC metres for water are also available.
Another option is to contact your local water authority.
If high salinity is confirmed, stop fertilising your avocado tree.
If the irrigation water is the source of the problem, switch to rain water or distilled water.
Next, flush out the excess salt in the soil by leaching.
This means watering your avocado tree a bit deeper to push the salts below the root zone.
To do this, use about 10%—20% more water than usual (known as the leaching fraction).
If your avocado tree doesn’t get better, it might be time to chat with a specialist.
5. Nutrient Deficiencies
Certain nutrient deficiencies can cause necrotic, brown spots on avocado leaves. The leaf edges and veins may also look scorched or burnt.
Keep an eye out for deficiencies in:
- Calcium
- Potassium
- Magnesium
- Phosphorus
How to solve nutrient deficiencies in avocado trees
Start by doing a soil test to find out which nutrients your avocado needs.
You can pick up a soil test kit online, which usually covers basic nutrients like nitrogen, phosphorus, and potassium.
For a more detailed report, consider sending a soil sample to a specialised lab.
Once you have the results, choose a fertiliser that targets the specific nutrient deficiency.
For overall health, a slow-release NPK fertiliser or a good compost works well.
Keep in mind that mature avocado trees need fertilising 2–3 times a year. Meanwhile, young trees should be fertilised more often, around 3–4 times a year.
6. Fungal Diseases
Several avocado problems — specifically fungal issues — can pop up in humid weather or if the tree is overwatered.
Many of these diseases can show up as browning on the leaves, including:
ANTHRACNOSE: Starts as yellow spots on the leaves, which turn brown and grow into large patches before spreading to the fruit
CERCOSPORA LEAF SPOT: Causes brown spots on avocado leaves and small cracks on the fruit’s skin
PHYTOPHTHORA ROOT ROT: A fatal disease that leads to yellowing leaves with black or brown tips; often caused by overwatering
VERTICILLIUM WILT: Avocado leaves turn brown and cling to the tree for months; branches can suddenly die back
How to treat avocado tree diseases
First, try to identify the exact disease affecting your avocado tree.
If the soil is soggy, check for root rot. Gently dig around the base of the tree to examine the roots. If they’re dark and foul-smelling, root rot is the likely issue.
In that case, stop watering the tree immediately and call an arborist if the damage is severe.
For other fungal diseases, here’s what you can do:
PRUNING: Trim away affected avocado leaves and branches to stop the infection from spreading.
FUNGICIDE USE: Spray the foliage with a copper-based fungicide every 1–2 weeks to protect healthy areas.
POST-HARVEST TREATMENT: For diseases that affect the fruit, you may need a post-harvest treatment. Use one that’s approved for avocados in Australia.
PROPER WATERING: Only water the tree when the soil is dry, and avoid getting the leaves wet.
If the problem persists, don’t hesitate to consult a specialist!
7. Pests
Pests can damage the avocado leaves by piercing them and sucking sap.
This causes the leaves to look pale and yellow before they turn brown as the leaf cells die.
Some pests can also inject harmful enzymes into the leaves, leading to dark spots or patches.
Watch out for:
- Thrips
- Aphids
- Beetles
- Caterpillars
- Spider mites
Regularly inspect your avocado tree for pests, especially during the warmer months.
Use a magnifying glass to examine the undersides of leaves, stems, and twigs.
You can also gently shake a few branches while holding a white sheet of paper underneath. See if any tiny bugs will fall out!
Getting rid of avocado tree pests
Prune any heavily infested parts of your avocado tree.
Then, spray all the leaves — focusing on the undersides — with a mixture of ½ tbsp neem oil, 1L water, and a few drops of dish soap.
Repeat weekly until the pests are gone.
Tips to Keep Your Avocado Tree Leaves Healthy
If your avocado tree leaves are turning brown, it’s usually a sign that something’s off.
Caring for your avocado tree properly can help prevent most leaf issues.
Monitor the weather regularly so you can protect your tree from extreme heat or cold.
Also, be sure to water the tree consistently. Keep the soil moist (not waterlogged!), and ensure good drainage to prevent root issues.
You can also add avocado-friendly plants nearby to improve the soil profile and make your garden more resilient.
If you need help with planting or general garden upkeep, don’t hesitate to chat with an experienced, professional gardener!
FAQs About Brown Avocado Leaves
Still stumped by those brown leaves? The extra info below might help!
Should I cut the dead leaves off my avocado tree?
Yes, you should cut off dead leaves from your avocado tree!
While the tree will drop dead leaves eventually, removing them helps redirect their energy to fruit production.
Plus, if the dead leaves were due to diseases or pests, clearing them helps prevent the problem from spreading.
Can I still save my avocado tree if the leaves are turning brown?
In most cases, yes — especially if you caught the problem early!
But if the issue is already severe, it might be best to consult a plant specialist for guidance.
Are brown leaves in avocados a problem or just part of the tree’s natural cycle?
Brown leaves in avocados can be perfectly normal. But sometimes, they’re a sign of a problem.
It’s normal for a few older leaves to turn brown and drop every 10–12 months. This is part of the avocado tree’s natural cycle.
But if lots of leaves are browning rapidly and dropping, that’s usually a sign that the tree is under stress.
