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

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.

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.

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.

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.

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.

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

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.

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?

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.

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!

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:

• Olive Tree Leaves Turning Brown
• Olive Tree Leaves Turning Yellow
• Olive Tree Leaves Curling
• Olive Tree Leaves Dropping Off
• Revive Olive Tree and Bring Back to Life
• Problems with Olive Trees in Pots & Solutions

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Are You Looking to Buy an Olive Tree? 

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.