White Spots on Olive Tree Leaves: Reasons | Cures | Prevention

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We used to see olive tree leaves silver-grey color as a sign of a healthy tree throughout the year, but dusty white spots or fluffy white stuff is definitely not their color palette and you should take care of it.

So what does it mean if you notice white spots on olive tree leaves? It can be multiple reasons such as fertilizer or insecticide residue easy to fix, or pest infestation which is more difficult to treat. By identifying the cause for this white stuff, and taking proper action as soon as possible, your olive tree will look healthy again and avoid the infestation to get worse and end up harming your olive tree.

Learn more about what can cause white spots on olive tree leaves, how it develops, and what you can do to prevent them.

white spots on olive tree leaves

Reasons for White Stuff on Olive Tree Leaves

You may be wondering what those white spots on olive tree leaves are. Can it harm your olive tree? Well, the answer to that question depends on the reasons listed below.

Reasons for White Spots on Olive Leaves Treatment / Prevention
1. Fertilizer or Insecticide Residue Wipe leaves with damp cloth or garden hose
2. Powdery Mildew Fungus Apply baking soda, milk, or neem oil and clean leaves
3. Wooly Aphids Attack  Use insecticidal soap; good washing with hot water; use homemade soapy water

Fertilizer or Insecticide Residue

You have just bought a beautiful olive tree, however, noticed white spots on olive tree leaves? Well, probably it is nothing serious and it is just a fertilizer or insecticide residue the nursery sprays on plants before shipping. Just wipe leaves with a damp cloth or a garden hose and your tree regain its natural healthy green color.

olive tree leaves with white spots in nursery due to fertilizer
These potted olive trees grow in a local garden center and have white spots on leaves due to a mix of fertilizing and dust

If you keep your olive tree outdoors, the white spots on leaves can appear after heavy rain which mixes dirt with water and builds up spots on leaves after it dries.

white spots on olive tree leaves
If your olive tree has such white spots – don’t panic! It is just fertilizer or insecticide residue

Powdery Mildew Fungus

Powdery mildew is one of the foremost widespread and simply identifiable tree fungal diseases. White or gray powdery spots appear, oftentimes covering most if not the whole leaf surface. It’s also found on tree stems, flowers, and even fruit. Fortunately, the symptoms of mildew are usually worse than the particular damage. Rarely is it fatal to the olive tree.

If you discover that your olive tree has mildew, don’t worry. Only advanced stages can cause olive tree foliage to yellow, curl, or turn brown and eventually cause the tree to defoliate prematurely. On flowering olive trees, the fungus can cause early bud drop or reduce the flower quality.

powdery mildew fungus
Example of heavy powdery mildew fungus disease on a plant

How to Get Rid of Powdery Mildew Fungus?

There are many ways or products to treat this fungal disease, but here I will provide my top 3 most natural options:

  • Baking soda is the best-known homemade organic solution to wipe out powdery mildew. Take 1 tablespoon of each – baking soda and liquid soap – to 1 gallon of water.
  • Milk works very well in the fight against this disease as well as improves olive tree health. Use a 1:2 ratio for milk and water.
  • Neem oil is a readily available organic option for disease and pest control.

For continuous protection, reapply it every 2 weeks to make sure fungus won’t come back. And for prevention, improve air circulation and ensure sufficient light for six hours or more each day.

Woolly Aphids Attack

olive tree pests wooly aphids 1
Woody aphid insects generally feed in groups. They suck sap on foliage, buds, twigs, branches, bark, and even roots

Fuzzy white spots on olive tree leaves can be caused by a woolly aphid colony. This infestation has the appearance of a white mold or snow covering the leaves and branches. Once you tap the branch, then you see all the bugs start wiggling and you know you have a woolly aphid colony.

fluffy white stuff on olive tree leaves
Woolly aphids create a white mold or snow appearance on olive leaves and branches

As well, woolly aphids create a sticky secretion aka honeydew that covers the leaves of your olive tree and drips down on the ground. Though it will not cause too much damage if there are just a few leaves or branches affected, however, you still must treat it. Otherwise, without treatment, the entire woolly aphid colony will make its way to other branches and damage your olive tree’s overall health. Consequently, your tree may suffer from the leaves browning or even wilting. That’s why it’s best to deal with them while they are still controllable.

 How to Get Rid of Woolly Aphids?

olive tree wooly aphids 1
Not-treated woody aphid insects significantly affect flowering and olive production

Now that you are aware of the wooly aphids leaving white stuff on olive tree leaves, the next question is how to get rid of it. Taking them out of your plants is easy.

  • Use insecticidal soap from the garden store and spray it on them
  • Fill a bottle with really hot water and spray them down
  • Make your own insecticidal soap by taking 1 spoon of dish soap and a quarter of a bottle of hot water, mixing it and it is ready to go
  • Looking for a creative way? Hoover them as this guy does in a video :)

Make sure you get rid of their eggs already attached to the branches. Then, hopefully, these creatures will no longer come back to the olive tree once taken out.

white stuff on olive leaves 1
If you are not sure what are white stuff on olive tree, try to wash it away. If it is fertilizer or insecticide residue left after spreading it in a garden center, it will go off very easily but if it is easily washable then

How to Prevent Olive Tree from Any Spots on Leaves?

1. Check Your Tree Regularly

Observing your olive tree regularly can help you to detect any abnormalities on your plant. Whenever you see even the slightest white spot on olive tree leaves, wash it away with soapy water. This method can prevent the beginning of any pest infestation which hinders the healthy growth of the olive tree.

Read more on how to care for olive trees in pots and find out main tips on how to maintain your olive tree in great shape!

problems with olive tree leaves dropping
Regular care and frequent monitoring will help you to avoid problems with olive tree leaves

2. Go Easy on Insecticides

Insecticides are a very helpful way to prevent pest infestations. You can use the most natural of soapy water or salty water once per year to wash your olive tree leaves.

Bear in mind, not all pest infestations need strong insecticides or chemicals to remove them. So prior to using it, make sure there is no better option for treatment so as not to end up damaging your olive tree irrevocably.

Last update on 2023-06-08 / Affiliate links / Images from Amazon Product Advertising API

3. Do Some Pruning

Pruning the olive tree regularly not only promotes its growth but can be an excellent way to eliminate the leaves showing any abnormalities. In case the pests just affected a few leaves or branches though have a huge threat to infect all the tree, pruning can be the right way to stop the spread.

4. Ask for Advice

If you follow this article and are still not familiar with the cause of white spots on olive tree leaves, ask for professional advice at the nearest garden store. Always learning more about how to deal with olive leaves problems may be handy in the future.

 

Final Thoughts

When you see some fuzzy white spots on olive tree leaves, don’t panic! It may be just an insecticide residue or mild woolly aphid infestation. Even if it can affect your plant’s growth, it will not pose permanent damage to the olive tree. Just deal with it right away to ensure that it will not get worse. Happy growing!

Read Next:

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If you are looking to add more potted trees or other plants to your orchard, or if you like to replace a neglected olive tree, the best places to get them are your local nursery or an online nursery.

One of the most reliable and the world's largest online nurseries is Fast Growing Trees. They deliver fast, neat, and healthy plants backed with a 30-day guarantee.

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10 thoughts on “White Spots on Olive Tree Leaves: Reasons | Cures | Prevention”

  1. Sardar Shazali

    Hi vangelis,
    Hope you are enjoying good health. I bought a olive plant of 1.5feet two years ago and it was bearing fruits at that time. Two springs have passed and my plant is almost 4 feet tall and healthy but not bearing fruits or even flowers. This winter I have seen a lot of Woolly Aphids on it so I sprayed the soil with dilute kerosene oil as recommended by farmer. There are no Woolly Aphids now and plant is healthy and green. But no fruits.
    My plant is just next to out water drainage. I want to know that is it due to lot of water supply that it is not bearing flowers for last two years.
    I will be very thankful to you on guiding me.
    Regards

  2. Hi Sardar, Hope you are doing well. Do you know the variety of your olive tree? Is it self fertile? My first guess is lack of pollination (reduced amount of bees or other pollinizers visiting the flowers) or your tree is cross-pollinating and another olive tree should grow next by in order to cross-pollinate your tree and produce fruits. In general, cross-pollination generally improves the fruit set of most varieties especially when the environmental conditions are not optimal. Good pollinators are Arbequina, Picual, and other trees. Also, it can be a lack of sunlight, inadequate irrigation. Other than that I need more information in order to pinpoint the reason that your tree is not producing.

  3. Julie McVeigh

    Hi Vangelis,
    Hope you’re well?! This might be a strange question to ask and probably not something you would ever consider doing! I am growing small standard olive trees (Olea Europea, bought last year) for the tables at my daughters wedding now postponed until February – they are all covered in tiny ‘olives’ which is good but I wondered if they would grow bigger quicker if I removed some or all the clusters of fruit? I am in UK
    Many Thanks
    Julie

  4. Hi Julie, I am glad to hear your olive trees growing well and have fruits! If you want to boost olive tree growth, keep it in full sun and fertilize it. I am afraid, removing olive fruits won’t make an olive tree grow quicker… Congratulations on your daughter’s wedding and wish these olive trees bring joy and longevity!

  5. Hi there. Hope you are well. Can you please tell me the best way to get rid of woolly aphids from my olive tree? Thanks in advance for your help. 🙏🏻

  6. Hi Georgie, the easiest way is to use insecticidal soap or neem oil. Also, you can use soapy water. Remove insects with a brush or strong jet of water.

  7. Hello,

    I’m wondering if you can help me, I have a medium size potted olive tree on my balcony. I noticed in early Summer some white fluffy stuff on the branches and also some of the leaves look like they have bite s out of them.

    I have just applied a neem oil/water/soap combo but am wondering if this will be enough? The love tree is loosing leaves fast now and I hope I am not too late to rescue it. I think its a European Olive tree.

    Thanks in advance for any help.

  8. Hi Diane, how is your olive tree after applying Neem oil treatment? Neem oil should work very well to remove insects, also, you can try insecticide soap. Once insects are removed your tree will recover slowly, just be patient.

  9. Hi
    My olive tree has white patches on the leaves where the leaves appear to have been eaten but not right through with the white area becoming paper thin. I can’t see any insects
    Please can you advise re what it is and how to get rid of it??
    Thanks Jo

  10. Hi Jo, first guess it may be fungus or bacteria. Check out your local garden center and get a fungicide, neem oil may also work.

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