A reader reached out to me and asked why their olive tree isn’t fruiting. I had a general idea, but I wanted to do more research to give them the best answer. So, I dug deeper and put together this guide. Here’s what I found.
Olive trees may not fruit due to factors such as insufficient sunlight, inadequate pollination, improper pruning, and nutrient deficiencies. To fix these issues, ensure your tree receives at least 6 hours of sunlight, plant pollinator varieties nearby, prune correctly, and provide balanced nutrition.
So, while olive trees won’t fruit because of several different reasons, how can we tell which issue is causing it, and more importantly—how can we fix it? Let’s take a look.
1. Lack of Sunlight
Olive trees, like most fruit-bearing plants, require adequate sunlight to produce energy for fruiting. They thrive with at least 6 hours of direct sunlight each day. If your tree is in a shaded location, it may struggle to produce fruit.
- Evaluate the location: Take a close look at where your olive tree is planted. Observe how much sunlight it receives throughout the day. If it’s getting less than 6 hours, consider relocating the tree or pruning nearby trees to allow more sunlight to reach it.
- Choose the right spot: If you’re planting a new olive tree, make sure you select a location that will receive plenty of sunlight. This will help set your tree up for success from the beginning.
For maximum sunlight, plant the olive tree on the south side of your property (in the southern hemisphere, this is north). If you have a southern-facing wall, you can also plant it near it as the wall helps reflect sunlight and heat onto the olive tree, even radiating heat into the night.
2. Improper Pollination and Variety
| Best Varieties for Fruiting | Flavor | Use |
|---|---|---|
| Arbequina | Mild, fruity | Oil production |
| Koroneiki | High oil content | Oil production |
| Frantoio | Robust, peppery | Oil production |
| Mission | Sweet, nutty | Table olives |
| Leccino | Fruity, mild | Table olives and oil production |
| Manzanillo | Mild, buttery | Table olives |
| Picual | Strong, fruity | Oil production |
Olive trees are primarily wind-pollinated, but they can also benefit from insect pollination. Some varieties of olive trees are self-fertile, while others require cross-pollination with a different variety to produce fruit. Ensuring proper pollination is essential for your olive tree to bear fruit.
Before you plant an olive tree, you should know if it’s a self-fertile or cross-pollinating variety. Self-fertile varieties can produce fruit without another tree nearby, while cross-pollinating varieties need another compatible variety within close proximity to successfully produce fruit.
If your olive tree requires cross-pollination, plant another variety of olive nearby that’s compatible for pollination. This will increase the chances of successful flower fertilization and fruit production. For best results, check the best pollinator varieties for your specific tree and plant them within 30-40 feet of your primary tree.
Although olive trees are primarily wind-pollinated, they still benefit from insect pollination. You can attract pollinators like bees and butterflies by planting a variety of flowering plants around your olive trees. This can help increase the chances of successful pollination and fruit production.
Recommended: The Top 5 Companion Plants for Olive Trees
Since olive trees rely heavily on wind for pollination, it’s important to consider wind patterns in your garden. Make sure there are no large wind barriers, such as walls or tall hedges, blocking the wind flow around your trees. If necessary, adjust your garden layout to improve wind circulation.
Keep in mind that young olive trees may take several years to begin producing fruit. In some cases, it can take up to 5 years for an olive tree to mature enough to bear fruit. Be patient with your tree, and make sure you’re providing the proper care during its early years.
3. Pruning
Pruning is an essential aspect of caring for olive trees, as it encourages new growth, improves air circulation, and helps shape the tree for better fruit production. However, improper pruning can also be a reason why your olive tree isn’t fruiting. Here’s what you need to know about pruning olive trees:
Why pruning is important: Olive trees naturally grow into a dense, bushy shape that can reduce sunlight penetration and hinder pollination. Proper pruning helps open up the tree’s canopy, allowing sunlight and air to reach the interior branches. This not only promotes healthy growth but also increases the tree’s fruit-bearing potential.
Pruning at the right time: The best time to prune olive trees is in late winter or early spring, just before new growth starts. This allows the tree to focus its energy on producing new growth and fruit during the growing season. Avoid pruning during the hot summer months or in the fall, as this can stress the tree and reduce its ability to produce fruit.
Pruning techniques: When pruning an olive tree, focus on removing dead, diseased, or damaged branches. Also, remove branches that cross each other or grow inward, as these can reduce air circulation and sunlight penetration. Aim to create an open, vase-like shape that allows light and air to reach the interior branches.
Avoid over-pruning: While pruning is important for promoting fruit production, be careful not to over-prune your tree. Removing too much growth at once can stress the tree and reduce its ability to produce fruit. As a general rule, don’t remove more than one-third of the tree’s total growth in a single pruning session.
4. Improper Nutrients
Nutrient management is crucial for the health and fruit production of olive trees. When olive trees don’t have enough nutrients, they develop issues such as yellowing leaves, poor growth, and reduced fruit production.
Lack of 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 |
Olive trees need a balanced supply of nutrients, including nitrogen, phosphorus, potassium (NPK), and micronutrients like iron, zinc, and magnesium. A deficiency in these nutrients can lead to various health problems and hinder the tree’s ability to produce fruit.
Causes of nutrient deficiency in olive trees can include:
- Degraded soil
- Imbalanced soil pH
- Sandy or poorly structured soil
To fix nutrient deficiencies, use organic matter like compost or well-rotted manure to improve soil structure and provide essential nutrients. In most cases, a 2-inch layer of compost applied around the tree’s base every 1-2 months works well.
Excess Nutrients
Over-fertilizing your olive tree can lead to problems as well. Excessive nutrients, especially nitrogen, can cause the tree to focus on producing vegetative growth such as leaves at the expense of fruit production. Over-fertilization can also cause root burn and weaken the tree’s overall health.
If you think you’ve over-fertilized your olive tree, flush the soil with water to leach excess nutrients from the root zone. Run a slow stream of water around the tree for 2-3 hours to help dilute the nutrients and move them further down into the soil.
How to Fertilize Olive Trees
Olive trees can benefit from a slow-release, balanced fertilizer or compost. Avoid chemical fertilizers if possible, as they can harm the soil’s beneficial organisms and lead to long-term issues.
The ideal fertilizer for olive trees should contain a balanced mix of NPK, as well as secondary nutrients like iron, zinc, and magnesium.
To see which fertilizer I use and recommend, see my recommended fertilizer page.
Soil pH is also important for olive trees, as it affects nutrient availability.
Olive trees prefer a soil pH between 7.0 and 8.0.
To measure your soil’s pH, you can use pH strips or a pH meter. If the pH needs adjustment, use appropriate soil amendments like wood ash, biochar, or lime for acidic soil, and sand, peat moss, or coffee grounds for alkaline soil.
Recommended: Are Coffee Grounds Good For Olive Trees? (Here’s The Answer)
More Tips for Better Fruit Production
In addition to sunlight, pollination, pruning, and nutrient management, there are several other factors that influence fruit production in olive trees. Here are some additional tips to help your tree produce more fruit:
- Water management: Olive trees are drought-tolerant, but they still require proper watering to produce fruit. Too much water can lead to root rot, while too little can stress the tree and reduce fruit production. Monitor your tree’s water needs by checking the soil moisture. It should feel like a wrung-out sponge, not too wet or too dry. Water deeply and infrequently, allowing the top 2-4 inches of soil to dry out between watering. This promotes strong root growth and helps prevent water-related issues.
- Temperature and climate: Olive trees thrive in Mediterranean-like climates, with hot, dry summers and cool, wet winters. If your local climate is not ideal for olive trees, provide extra care to ensure fruit production. For example, if you live in a colder region, protect your tree during winter by wrapping it in burlap or using a tree guard. In extremely hot climates, make sure the tree has sufficient water and is protected from excessive heat.
- Disease and pest control: Olive trees can suffer from various pests and diseases that can negatively impact fruit production. Common issues include olive fruit fly, olive knot, and verticillium wilt. Inspect your tree regularly for signs of infestation or disease, and address any problems as soon as they arise. Use organic pest control methods, such as introducing beneficial insects or applying neem oil, to minimize chemical use and maintain a healthy ecosystem.
- Girdling: Girdling, also known as ring-barking, is a technique used to encourage fruit production in some fruit trees, including olive trees. By removing a narrow strip of bark around the tree’s trunk, you can temporarily disrupt the flow of nutrients, causing the tree to redirect energy into fruit production. While girdling can be effective, it can also stress the tree and should be used with caution. Only attempt girdling if you’re confident in your ability to do it correctly, and consult with an experienced arborist if you’re unsure.
- Tree age: Olive trees can take several years to begin producing fruit. In some cases, it may take up to 5 years or more for a tree to mature and start bearing fruit. Be patient with your tree and provide consistent care during its early years.
Sources
- https://gardeningsolutions.ifas.ufl.edu/plants/edibles/fruits/olives.html
- https://journals.ashs.org/jashs/view/journals/jashs/133/5/article-p639.xml
