What are the Characteristics of an Olive Tree?

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Olea Europaea

Where would we be in the world if we didn’t have olive trees? Salads would be dry without extra virgin olive oil, food would constantly be stuck to our pans, and pizzas would be significantly less adorned with little salty bombs of flavor.

The olive is a small fruiting tree that is part of the botanical family Oleaceae. They are native trees to the Mediterranean basin, and they have been cultivated by humans for thousands and thousands of years.

We needn’t really explain that olive trees are of incredible agricultural importance, but we will anyway. They’re really important! Olives and olive oil are the most integral ingredient in Mediterranean cuisine, and they are incredibly popular cultivars in South America, South Africa, Chine, Australia, New Zealand, Mexico, and the United States.

Not only are olive trees wonderful for providing us with wonderful food, they also have coveted and high quality wood. AND they’re super long lived! There are some trees that grow in Portugal that are almost 3,500 years old!

Let’s not forget about the very symbolic image of the olive branch! The olive branch holds a great amount of spiritual significance, and has long been a representation of abundance, glory, and above all, peace.

If you have been following along the journey of 101 Types of Trees, you will know that the olive tree is the 101st and final tree in our crazy list! It’s been a long road, learning about all the incredible trees that grow all over the world. Take it from me, the person who has done hundreds of hours of research, I feel like a much richer person for having learned the intimate details of our woody plant friends.

green olives growing on a slender branch with rain drops dripping off of them with blurry forest background

What do Olive Trees Look Like?

Root System

Olive trees are very resilient trees, and a lot of that is thanks to their root system. These trees are equipped with both a shallow and wide spreading root system, as well as a strong taproot.

The shallow root system only lives in the topsoil, and sometimes these roots become visible above the soil. These roots help create stability, and is where the majority of the water is absorbed.

Taproots – something that certain trees have in common with carrots – are a few, very large roots that grow almost vertically down into the soil. This is like the foundation of the trees’ stability, and where the tree is able to obtain moisture in drought-like conditions.

Dimensions

This plant is classified as either a small tree, or as a large shrub. They can grow between 8 and 15 meters tall, which a wide trunk diameter.

beautiful and mature olive trees with gnarled trunks growing in rows with lavender bushes growing underneath them

Growth Pattern

Olive trees have very wide trunks that are gnarled and twisted. Trunks can be either single stem or multistemmed, with the trunk splitting quite low to the ground. Manicured trees can hold a very attractive rounded shape, whereas trees growing in the wild have more of a open and irregular crown spread.

Bark

Olive tree bark will be either a light brown or a light gray color, depending on the age and growing location of the tree. A young olive tree will have smooth bark, whereas old trees have bark that is more rough, and grows twisted as the trunk changes growth pattern as well. The bark on a mature tree will will have deep fissures and high ridges, and it will exfoliate away in thin scale-like plates.

Foliage

Olive trees are evergreen, meaning that their foliage will remain green and persist all year long, regardless of the season.

Olive tree leaves are silvery green in color, they are more pale on the underside, and more dull on the topside. A leaf is a narrow oblong shape, usually between 1 and 4 inches long, and 0.3-1.5 inches wide. Leaves grows symmetrically along a twig.

looking up at the sky with olive tree branches and leaves growing prosperously and young green olives ripening

How do Olive Trees Reproduce?

Flowers

Olive trees have two different types of flowers. They have both male flowers that are pollen producing, and “perfect” flowers that have both male and female sexual characteristics.

A male flower is a yellow/white color, whereas the perfect flowers are more of a green/yellow color. These flowers have 4 simple petals and bright yellow stamens.

Flowers are borne in clusters in the axils of the leaf stems, and both types of flowers can occur on the same tree. The flowers with both male and female sexual characteristics will be pollinated either by an insect, like a bee, or through wind-pollinated, where pollen is carried by the wind to the opening of a flower.

tiny little olive tree flowers growing in clusters waiting to be pollinated with blurry background of olive leaves

Fruit

Once a flower is fertilized, it will produce a fruit in the form of a drupe. A drupe is a small fruit with a single stone, or pit in the centre, where the flesh of the fruit grows outward from. These drupes are otherwise known as olives! When growing in the wild, olives will be much smaller with less flesh than the ones that are cultivated for commercial harvest.

Olive fruit is ovular in shape with one stone in the center. They have a very thin skin and a thick, meaty textured flesh. Olives can be either green or purple. Black olives are actually artificially colored!

Types of Olives

Olives are classified into 3 different groups in fruit production, and these categories are organized according to the level of ripeness of the fruit when they were harvested. 90% of harvested olives are used for olive oil, whereas 10% are used as table olives.

Green Olives – green olives are picked when they have grown to their full size. Their skin appears as being ripe, but the inner flesh is still green, bitter, and a little bit firm.
Semi Ripe Olives – semi ripe olives are harvested when they have just begun their ripening cycle. This is indicated when their skin color changes from green to either red or brown. Though the skin appears ripened, the inner flesh still isn’t all the way ripe.
Black/Ripe Olives – black or ripe olives are picked when both the skin and the inner flesh has reached full maturity. The color is either purple or brown naturally with a soft and savory flesh.

Once olives have been harvested, they must then be processed. Raw olives are naturally very bitter, and in order to make them enjoyable, they must be first cured or fermented.

farmers hands holding a bunch of picked olives at different levels of ripeness

Sexual Maturity

The average olive tree is able to start producing flower and fruit crops as early as 5 years old, though it is more common for this to occur closer to the age of 12. This leaves for ample opportunity for prosperous crop seasons, as some of these trees are known to live almost 3,500 years!

Where did Olive Trees Originate?

Olive trees have been around for a long time. There is fossil evidence that proves the existence of olive trees some 20-40 million years ago in the Oligocene era!

Wild olives are known to have been harvested as early as 19,000 BC in the eastern Mediterranean, and it is estimated that they have been farmed and cultivated by humans for the past 7,000 years.

These trees haven’t always grown in North America. They were first brought to the Americas by Spanish colonists in the 1500’s, and they have been a major source of agricultural value in the America’s ever since then.

Where do Olive Trees Grow?

Since their origination, olive trees have been successfully cultivated all over the planet, where there is a suitable climate for their prosperous growth. They can usually be found growing on limestone slopes, and along coastlines.

Though their greatest population occurs in the Mediterranean region, olive groves are present in huge numbers all over South America, North America, South Africa, China, Australia, New Zealand, and Mexico. They have a rather expansive growing zone, and can exist in USDA zones 8 and 9, whereas some more cold hardy varieties can exist in 10 and 11.

What are the Growing Conditions of the Olive Tree?

Soil

Olive trees can grow in any type of light soil, even clay derived soil as long as it is will drained. These trees do not perform well in rich soil, as this makes them predisposed to certain diseases. They grow far better in low nutrient soil.

Water Level

Olive trees are very drought tolerant, thanks to their sturdy taproot and extensive shallow root system, though they do prefer to exist in regions that receive moderate annual precipitation.

Temperature

Though olive trees are relatively cold hardy, they will not be able to survive in an area if the winter temperature dips below 14 degrees Fahrenheit regularly.

Sun Exposure

Olive trees are entirely shade intolerant, and they must exist in full sun conditions.

wild olive trees with huge gnarled trunks and dense crowns growing next to a pathway and rocky soils

How are Olive Trees Used?

Ornamental Tree

Thanks to their attractive evergreen foliage, lovely spring flowers, easy-care, and edible fruit, olive trees make for a very popular ornamental tree. Thanks to their small size and relatively easy-care, they are also a rather popular option for the art of bonsai, or as a simple indoor olive tree.

Wood

Though you may not have expected, olive trees actually have very prized wood as well. Olive wood is known for being hard, durable, close grained, with a very high combustion temperature. Olive wood is very close grained and attractive in appearance. It is a yellow or light brown color with veins of a darker brown color.

Because this tree is slow growing and the tree is so small, the price of olive wood is rather high. This wood is used for the creation of fine furniture, woodenware, and decorative items.

Fruit Tree

It is already a known fact that olive trees are most used for the production of their delectable fruits. As we mentioned earlier, 90% of harvested olives are used to make olive oil, whereas 10% of harvested olives are used as table olives.

bottles of olive oil a mortar and pestle and bowls of different olive varieties all sitting on a wooden table with a blurry forest background

FAQs

Are olive tree leaves edible?

Because people are so focused on the fruit set of this plant, it is easy to forget that the leaves of the olive tree are also edible! And they are available all year long since it is an evergreen variety. Olive tree leaves can be used to make teas and extracts.

Are olive trees self pollinating?

Though the arbequina olive variety is self pollinating, and it will be able to produce its own fruit, the crop yield will only increase if another tree is introduced to the area.

How deep do the roots of an olive tree grow?

Olive trees are very resilient trees, and a lot of that is thanks to their root system. These trees are equipped with both a shallow and wide spreading root system, as well as a strong taproot.

The shallow root system only lives in the topsoil, and sometimes these roots become visible above the soil. These roots help create stability, and is where the majority of the water is absorbed.

Taproots – something that certain trees have in common with carrots – are a few, very large roots that grow almost vertically down into the soil. This is like the foundation of the trees’ stability, and where the tree is able to obtain moisture in drought-like conditions.

Can olive trees grow indoors?

A small olive tree may just be the right option for your next indoor plant. Planting an olive tree in a pot is a great way to keep the plant happy, and depending on which variety you choose, it can be a very manageable indoor houseplant.

How do you care for an olive tree?

Whether you are growing your olive tree in your garden, in its own planter, in a shabby container, or in a lovely pot, if you follow these growing tips, you could quickly consider yourself an olive farmer.

First things first, if you purchased an olive tree from the nursery, dwarf variety or otherwise, ensure that the root ball is well broken up before planting it.

Ensure that the location receives full sunlight, as these trees are shade intolerant. Though they can tolerant many soil types, it is best to choose a light soil that is low in nutrients.

A young tree is rather sensitive to both temperature and watering, so make sure that you plant it once there is no more threat of winter frost, and watering is kept at a moderate level.

Do olive trees grow in the shade?

Olive trees are completely shade intolerant, and much prefer to exist in full sun conditions.

How tall do olive trees get?

This plant is classified as either a small tree, or as a large shrub. They can grow between 8 and 15 meters tall, which a wide trunk diameter.

How fast do olive trees grow?

Olive trees are a painfully slow growing tree, and some will only grow 1-2 inches per year!

What is the average life expectancy of an olive tree?

The average life expectancy for an olive tree is 500 years, though there are some trees that are known to be closer to 3,500 years old.

Where does the oldest olive tree grow?

The oldest known olive tree lives in Mouriscas Abrantes, Portugal, and is an estimated 3,350 years old.

What does the olive tree symbolize?

When do olive trees fruit?

The harvesting of olive fruit usually takes place between mid-autumn to mid-winter, depending on the olive variety. Olives are classified into 3 different groups in fruit production, and these categories are organized according to the level of ripeness of the fruit when they were harvested.

When should you prune an olive tree?

It is best to reserve pruning after winter’s end, and before before the summer before the tree starts to open its buds. This way you can control the crop, and visually detect where the crop yield will be.