Gardeners growing olive trees may have to contend with leaf loss at some stage of their life cycle. Is this something that you need to worry about?
Different tree species shed their leaves periodically, depending on many factors. This is a fairly natural process that helps them preserve resources and promotes robust growth.
However, the problem is trees shedding more leaves than expected.
And if that’s the case, you should know how to handle this problem to ensure your trees remain healthy.
Let’s get going.
The Life Cycle of an Olive Tree
Whether you’re a veteran gardener or a novice, understanding an olive tree’s life cycle is essential to identify problems and apply remedies.
Olive trees are some of the oldest tree species globally, with some producing olives for centuries. For the record, their average lifespan is 500 years. The trees prefer growing in Medittererean climatic conditions.
According to the US Department of Agriculture, olive trees grow well in plant hardiness zones of nine to eleven. They are usually propagated from cuttings taken from the parent plant at least two years old.
The trees have the potential to grow to 50 feet and spread as wide as 30 feet. Fruit bearing usually happens after about 4-5 years.
Olive trees need good care for optimal fruit production despite their toughness and ability to survive harsh weather.
The trees produce flowers of both gender types, pollinated by wind. Some varieties are self-pollinating, while others are cross-pollinated.
An interesting aspect about olive trees is there on and off years in fruit production. During the ‘off-year,’ the tree produces several small fruits, followed by the ‘on-year’ whereby the fruits are fewer but comparatively larger.
Their fruits are harvested during the autumn months. Water and full sunlight are vital for a prolonged life span.
Why Your Olive Tree Is Losing Leaves And How To Fix?
If you’ve noticed leaves falling off your olive tree, look closer to see whether it’s a usual occurrence or a different case. It’s natural for them to shed their leaves during the dormant winter season.
However, if the leaf free fall is massive and continuous, other factors could be at play.
- Little or excessive watering
- Low or extreme temperatures
- Improper/Insufficient nutrients
- Insufficient light
- Transition shock
We look at each of these factors comprehensively below.
1. Little/ Excessive Watering
Olive trees are hardy and can thrive in dry, harsh conditions. That helps explains why excessive watering could lead to leaf loss problems.
Waterlogged soil interferes with their healthy growth. Signs of too much water are leaf yellowing owing to poor aeration or potential rotting of the roots.
Leaf yellowing in olive trees due to overwatering is somewhat different from the one caused by nutritional deficiency. The yellowness in the case of the former shows up in a mosaic pattern.
Common Signs of Overwatering in Olive Trees
- Leave droppings
- A constantly wet tree base
- Curling of new growth and leaves
- Fruits dropping prematurely
- Leaves turning brittle, yellow or pale green
Underwatering manifests in the same form and leads to the same outcome— leaves yellowing and dropping.
Check other accompanying symptoms to know whether the yellowing results from overwatering or underwatering.
How To Fix?
Understand the water requirements of your olive tree and only water them when needed. A quick way to determine if your soil is overwatered or in dire need of water is to stick your fingers two inches deep.
An underwatered soil will feel dry and crusty. Some gardeners prefer using a moisture meter to be sure. If your olive plant is potted, you should only water the plant when the soil is dry.
The potting mix should be well-draining to ensure excess water flows out. Ensure there is a working drainage system to prevent waterlogging and rotting of the roots.
You should use sandy soil as a planting medium ideally.
2. Low/ Extreme Temperatures
Your olive tree could lose leaves due to low or extreme temperatures. As mentioned earlier, they thrive best in USDA plant hardiness zones of 9 -11.
A prolonged period of deviation from these zones could mean exposure to damaging temperatures.
Besides the natural shedding in winter, the trees will lose leaves under low temperatures to signal unfavorable conditions. A tell-tale sign of this is young and fresh leaves falling off instead of the old and crusty ones.
Low temperatures induce dormancy, while extreme temperatures stress up the trees. A stressed tree will also lose its fruits and flowers prematurely.
How To Fix?
Maintain a temperature range of 26 -32 degrees Celsius around the trees. Cover them with burlap, sheets, or tarps if the temperature falls sharply.
Ensure availability of sufficient sunlight and nutrients while maintaining a healthy watering regime.
A stressed plant takes time to recover, and you will need to be patient to ensure its recovery.
Several infections could render your olive tree leafless. Let’s look at each of them and their remedies.
3.1 Verticillium Wilt
Verticillium wilt is a fungal infection that causes the leaves of olive trees to dry and drop, leading to its early demise.
The fungus infection is soil-borne. It enters via the roots and spreads throughout the entire plant or tree.
How To Fix?
Verticillium wilt has no cure, unfortunately. The best thing to do is to plant resistant species and varieties.
3.2 Root Rot
Root rot is a fungal disease caused when plants’ roots are exposed to excess water. Poor drainage and overwatering are the two leading causes of the disease.
Your plant will lose foliage because it’s no longer receiving nutrients and water from the roots. The ultimate result is stunted growth and death after 1-2 years.
Check root rot in your plant by uprooting it and scrapping one inch of bark. A black or brown tissue underneath indicates the root is dead.
How To Fix?
Control rot by examining the roots for infection. Prune any infected parts straightaway. Also, rinse the root system with hydrogen peroxide solution to eliminate the bacteria responsible.
As a precaution, do not return the plant to the same spot to avoid reinfection— transfer it to a different area or change the potting soil altogether.
3.3 Olive Knot
Another infection you want to check on is the bacterial infection known as Olive Knot. The disease spreads through water affecting major parts of the plant, including branches, twigs, limbs, roots, leaves, and trunks.
It is characterized by galls of up to 2 inches in diameter on the affected plant parts.
The bacteria usually enter via cuts and wounds on the plant’s exterior.
The galls restrict the movement of food and water from roots to the leaves leading to starvation and death of the plant. Your olive trees could be losing leaves as a potential side effect.
How To Fix?
Treat your olive trees with copper-based bactericides to control the infection and prevent it from recurring. The best time for applying is before the onset of rains in fall.
4. Improper/Insufficient Nutrients
How you apply nutrients can have a big implication for the growth of your olive trees. Nutrients applied at the right time and in the right quantities will make your trees flourish.
However, either of the extremes could result in severe leaf loss. Insufficient nutrients lead to stunted growth.
Similarly, an overdose of the nutrients leads to roots getting burnt. This further results in the cutting of water and food supply to the rest of the plant.
How To Fix?
Common signs of a nutritionally deficient tree include yellow leaves, poor fruit production, and stunted shoot growth.
If your trees are nutritionally inadequate, it might be best to conduct a soil test to determine what nutrients could be missing.
It will also help you know what quantities are required for the best results.
If it’s a problem of overfertilization, have the nutrients leech to the lower soil layers. This can be done by pouring plenty of water onto the soil.
However, ensure there is a proper drainage system, or you would be trading one problem for the other— potential root rot.
You could also repot the trees in a new location or pots.
5. Insufficient Light
Your olive trees could be losing leaves due to insufficient sunlight. When you purchase a new plant, you expose it to a new lighting regime not similar to the one it was accustomed to in the nursery.
This results in the plant shedding its old leaves to produce new ones better suited to the new conditions.
There is one quick way of identifying this occurrence. If the leaves appear pale and move in one direction, that’s a clear sign of insufficient light.
How To Fix?
Olive trees need at least six hours of direct sunlight. You should ensure they are grown in a naturally well-lit area.
You might want to supplement natural light with artificial light if growing them under hazy weather conditions.
6. Transplanting Stress
Another cause of leaf loss in olive trees could be transplanting them from one location to another, especially if the new environment is harsh.
This causes stress in the plant, forcing it to shed leaves to preserve resources. The situation can be further aggravated by root damage while transplanting.
How To Fix?
Harden your olive plants by slowly introducing them to new environmental conditions. For instance, if moving the plants outdoors, gradually acclimatize them by keeping them outdoors for an hour every day.
Slowly increase the exposure duration till the plants are fully adapted to the new conditions and are ready to be transplanted.
You should also avoid damaging the roots during transplanting. We advise watering the area first before you do the uprooting.
If your olive trees have been giving you sleepless nights, you now know why that could be happening. Typically, the trees shed leaves during the dormant winter months.
But this is never always the case. Sometimes other factors could be at play leading to the leaf loss.
Luckily we have highlighted each of the possible factors and how you can address them to bring your trees back to life. Happy gardening!