4 Reasons Why Olive Trees Drop Their Leaves (& Fixes)

Our olive tree is recently getting browning and dropping leaves. We were a bit concerned, so we did some research to find out more. Here’s what we found.

Olive trees drop their leaves due to seasonal changes, water stress, nutrient deficiencies, and pest or disease issues. To fix this, ensure proper watering, maintain balanced soil nutrients, and regularly inspect for pests or diseases.

Let’s take a look at how we can tell which issue the olive tree has and how we can fix it.

1. Seasonal

Olive trees, like many other plants, have a natural cycle of shedding old leaves and growing new ones. This typically happens in late winter or early spring, as the tree prepares for new growth.

However, olive trees are evergreen, so they don’t lose all of their leaves in the fall and winter like deciduous trees (apples, cherries, etc).

Don’t confuse this natural process with a problem that needs solving! To help with this, here are some tips to help you recognize seasonal leaf drop:

• Observe the timing: If leaf drop occurs during late winter or early spring, it’s likely a natural process.
• Examine the leaves: Healthy leaf drop will mostly involve older leaves, while new growth remains unaffected.

But what if your olive tree is dropping leaves in the spring or summer? What should we look at next?

2. Improper Watering

Olive trees are drought-tolerant plants, but they still require proper watering to thrive. Over-watering or under-watering can cause stress to the tree, leading to leaf drop. Here’s how to maintain the right balance for your olive tree:

• Soil check: Before watering, check the soil’s moisture by pushing your finger into the top 2-4 inches. If it feels dry, like a wrung-out sponge, it’s time to water. Checking soil moisture regularly helps prevent over- or under-watering, as factors like temperature, humidity, and rainfall can affect how quickly the soil dries out.
• Deep watering: Give your olive tree a thorough watering to encourage deep root growth. This helps the tree better tolerate drought conditions. Water the tree slowly and deeply, allowing the water to penetrate the soil and reach the roots. Avoid frequent, shallow watering, as it encourages shallow root systems that are more susceptible to drought stress.
• Drainage: Ensure your tree is planted in well-draining soil or a container with drainage holes to prevent waterlogging and root rot. Olive trees are susceptible to root diseases if their roots sit in water for extended periods. If you’re planting in a container, use a high-quality potting mix that retains moisture while allowing excess water to drain away.
• Mulching: Apply a 4-12 inch layer of organic mulch, such as straw or wood chips, around the base of your olive tree. Mulch helps regulate soil temperature, retain moisture, and reduce water evaporation. It also suppresses weeds that could compete with your tree for water and nutrients. Be sure to leave a gap between the mulch and the trunk to prevent pest problems and rotting.
• Watering frequency: Olive trees require less frequent watering than many other fruit trees. During the growing season, water your tree every 10 to 14 days, or as needed based on your soil moisture checks. In hot, dry weather, you may need to water more often to maintain soil moisture. In winter, reduce watering frequency, as the tree’s water needs are lower during its dormant period.
• Irrigation methods: Consider using drip irrigation or a soaker hose to water your olive tree. These methods deliver water directly to the root zone, reducing water waste and minimizing the risk of disease caused by wet foliage. They also provide a slow, steady supply of water, ensuring that the soil doesn’t become waterlogged.

Now that we’ve covered watering practices in-depth, let’s move on to nutrient management to further support your olive tree’s health and prevent leaf drop.

3. Improper Nutrients

Nutrient Deficiency	Leaf Symptom
Nitrogen	Entire leaf is pale or yellow
Iron	Dark green veins, rest of the leaf is yellowing
Zinc	Yellow blotches
Manganese	Broadly pale leaves, foliage color looks mottled or smeared

Nutrient management is a crucial aspect of maintaining a healthy olive tree, as deficiencies can lead to various symptoms, including leaves yellowing, browning, and dropping.

To ensure your tree receives the nutrients it needs, start with a soil test to determine its nutrient levels and pH. This information will help you select the right amendments and fertilizers for your tree.

Olive trees also prefer slightly acidic to neutral soil with a pH of 6.0-7.0.

When it comes to fertilization, opt for a balanced, slow-release fertilizer with an NPK ratio of around 10-10-10, unless your soil test indicates that specific nutrients are lacking.

To see which fertilizer I use and recommend, see my recommended fertilizer page.

The best time to apply fertilizer is in early spring before the tree starts its active growth phase. Remember to follow the package instructions for the correct application rate.

In addition to using commercial fertilizers, incorporating compost and other organic matter into the soil around your olive tree can provide essential nutrients while also improving the soil’s structure and water-holding capacity.

Organic matter can also help regulate soil pH, creating a more favorable environment for your tree to thrive.

However, it’s essential to avoid over-fertilization, as this can harm your olive tree and contribute to leaf drop.

Excessive nitrogen, for instance, can cause rapid and weak growth, making the tree more susceptible to pests and diseases.

Follow the package’s instructions and fertilization schedule on the results of your soil test to ensure your olive tree receives the nutrients it needs without over-fertilizing it.

4. Pests and Diseases

Pests and diseases can cause significant stress to your olive tree, leading to leaf drop and other symptoms. Monitor your tree regularly and take action to control pests and diseases as soon as they appear. Here are some strategies to help protect your olive tree:

Pests

Inspect your tree frequently for signs of pests, such as aphids, scale insects, or olive fruit flies. Look for evidence of their presence, like sticky residue (honeydew), sooty mold, or tiny insects on the leaves and branches.

If you spot pests, you can use organic solutions like neem oil or insecticidal soap to control them. Remember to follow the product instructions for proper application.

For example, when my lime tree had aphids recently, I used a jet of water to knock them off. That’s all that was needed and they didn’t come back! Again, neem oil as well as ladybugs (a natural predator of aphids) are other great options.

Diseases

When it comes to diseases, olive trees can be affected by various fungal infections, such as anthracnose, verticillium wilt, and peacock spot. These diseases can cause leaf drop, discoloration, and other symptoms.

To prevent the spread of fungal diseases, ensure proper air circulation around your tree by pruning and spacing your trees appropriately. Remove any infected leaves or branches to prevent the disease from spreading further.

Another critical aspect of disease control is keeping the area around your tree clean and free of debris.

Fallen leaves, fruit, and other plant material can harbor fungal spores and pests, providing them with a place to overwinter and re-infest your tree the following year. Regularly raking and disposing of debris can help reduce the risk of pest and disease issues.

Finally, maintain the tree’s overall health by properly watering, providing nutrients, and pruning (overlapping or clustered branches as well as “suckers”—the new sprouts between limbs).

A healthy olive tree is more resistant to pests and diseases, and less likely to suffer from leaf drop and other issues.

Final Thoughts

That was a lot of info, but if you’d like, here’s a recap:

1. Understand seasonal leaf drop as a natural process and distinguish it from other causes.
2. Ensure proper watering by checking soil moisture, providing deep watering, and promoting good drainage.
3. Manage nutrients by testing soil, using appropriate fertilizers, and incorporating organic matter.
4. Control pests and diseases through regular inspections, using organic treatments, and maintaining overall tree health.

Recommended

How to Fix Curling Leaves on Olive Trees (3 Ways)

Why Olive Trees Get Brown Leaves (& How to Fix It)