Olive: Everything You Need To Know About This Evergreen Tree

The olive tree, recognized by the botanical name Olea europaea, which means ‘European olive,’ is a small tree group in the Oleaceae family, typically found in the Mediterranean Basin. The species is grown in all Mediterranean countries and South Africa, South America, China, India, Mexico, Australia, New Zealand, and the United States.

In the Mediterranean region, this fruit is also known as the olive. It has a significant agricultural purpose as a source of olive oil; it is one of the Mediterranean cuisine’s primary components.

The tree is grown for olive oil, olive leaves, fine wood, olive fruit, and ornamental plants. Around 90% of all picked olives are converted into oil, whereas only 10% are used as table olives.

Common NameOlive
Botanical NameOlea Europaea
Plant TypePerennial Tree
Size (Fully Grown)About 25 To 30 Feet In Height (About 7,6 To 9,1 Meters)
Sun ExposurePrefers Full Sun
Soil TypeOne That Drains Well
Soil pHFrom 5.5 To 6.5
Flower ColorWhitish
U.S. Hardiness ZonesDepending On The Variety, 8, 9, 10, And 11
Native AreaMediterranean region

How Many Olive Varieties Are There?

In these days, there are over 500 different cultivars. Here we have listed some of the most common ones:

  1. Beldi
  2. Bidni
  3. Gordal
  4. Barnea
  5. Bosana
  6. Azeradj
  7. Mission
  8. Amfissa
  9. Calabria
  10. Cailletier
  11. Ascolano
  12. Picholine
  13. Kalamata
  14. Arbosana
  15. Aglandau
  16. Bouteillan
  17. Arbequina
  18. Biancolilla
  19. Manzanilla
  20. Castelvetrano

What Is The History Of The Olive Tree?

Fossil evidence suggests that in the Oligocene, a country that we now know as Italy and the eastern Mediterranean Basin is where the tree has its roots. In the Mediterranean regions, olive was first grown about 7,000 years ago. The edible one, dating back to the early Bronze Age (3150 to 1200 BC), seems to have coexisted with humans for around 5,000 to 6,000 years.

We don’t know the exact heritage of this tree. In Macedonia and other places across the Mediterranean, researchers have discovered fossil Olea pollen, which shows that this genus is an original part of the Mediterranean ecosystem. In the palaeosols of the volcanic Greek island of Santorini (Thera), fossilized leaves of Olea were discovered and were dated to around 37,000 BP.

There were also found imprints of olive whitefly larvae on the leaves. The same insect is commonly found on olive leaves today, indicating that the co-evolutionary plant-animal relationships have not shifted since that time.

Other leaves found on the same island date back to 60,000 BP, making them the Mediterranean’s oldest surviving olives. They were also cultivated widely in Crete as far back as 3000 BC, and they may even be the cause of the Minoan civilization’s richness.

The Journey To The States…

Olives are not native to the USA. It was introduced to the New World by Spanish settlers, where its cultivation thrived in modern-day Argentina, Chile and Peru. In Lima, Antonio de Rivera cultivated the first olive seedlings that he brought from Spain in 1560.

The cultivation of the trees eventually spread along the dry Pacific coast of South America, where the growing conditions were close to the Mediterranean. Spanish missionaries in California founded the tree in the 18th century.

The plant was first grown in 1769 or later around 1795 at Mission San Diego de Alcalá. Orchards were established on other missions, but in 1838, an investigation only found two olive orchards in California. From the 1860s onwards, cultivation for oil gradually became an incredibly successful business operation. In Japan, on Shodo Island, which became the cradle of cultivation, olive trees’ first thriving plantation took place in 1908.

These days (even though this info is already outdated), in 2005, there were approximately 865 million olive trees in the world. A large proportion of these was grown in the Mediterranean region, with traditionally marginal lands accounting for no more than 25% of the olive-planted area and 10% of the oil area.

How To Identify An Olive Tree?

Olive tree produces many branches with a height that ranges from 25 to 40 feet (about 7,6 to 12,2 meters). Its leaves are dark green above and silvery on the underside, leathery and lance-shaped, and on the twig, they are paired opposite each other.

Leaves

As we already discussed, the olive tree leaves are green above and silvery on the underside. The leaves look a bit leathery, and they are lance-shaped. Lastly, there is the twig where the leaves are paired opposite each other. The green leaves’ size measure around 1,6 to 3,9 inches (about 4 to 10 cm) long and 0.39 to 1.18 inches (about 1 to 3 cm) thick, and they are oblong. The trunk, on the other hand, is gnarled and twisted.

Flowers

When it’s late spring, the trees start to flower. This is when the tree produces small, whitish flowers in clusters that are in the leaf axils. There are two kinds of flowers, ones that comprise both male and female parts that, in the end, grow to fruits. The second ones are males that only produce pollen.

Fruit

The fruit olive tree produces a green drupe that usually becomes blackish-purple when it’s completely ripe. When the fruit is mature, some of the fruits are green, and others transform to copper brown shade.

Best Growing Conditions For An Olive Tree

An environment that experiences a mild winter and a long plus dry, hot summer is optimal for an olive tree; a subtropical climate. The reason why a subtropical climate is perfect for it is because they are vulnerable to severe frost.

So, only zones 10 and 11 are optimal for olives, but even zones 8 and 9 might be suitable for some varieties.

Temperature

So, as we’ve discussed, the trees want a long, hot summer, while the winter should be chilly but not freezing. Don’t worry too much because a mature tree can withstand a temperature that is down to 15°F (about -9,5°C). But a winter that’s long with such low temps can turn out to be harmful and even deadly for the tree.

Soil And Sun

Soil types like sandy loam are suitable for olive trees. But the most important thing is that the soil won’t get waterlogged while still having a high water holding capacity. For example, if you take good care of heavy irrigation, sandy soil works well. It’s also essential to take care of the proper soil pH, which in the case of an olive tree is 5.5 to 6.5.

An olive tree needs something other than good soil to thrive. That’s why a regular water supply is also essential. The trees need regular watering, and if you don’t take good care of that, the tree will suffer, even though they are pretty drought tolerant.

Do Olive Trees Need Lots Of Sun?

To grow this tree successfully, remember to select a location with at least six hours of bright sunlight per day, but the ideal is full sun.

Water And Fertilizer

Once you’ve planted your tree, you might not have to water it ever again. But if you want it to prosper and produce fruits, I would recommend you to keep the soil moist. So, if you expect to get “fruit from your labor,” remember to water the plant frequently.

Based on the period of the year, young olive trees may need fertilizing after planting. To remain healthy and to produce yield every year, existing trees need fertilizing. So, with a fertilizer that has a 16-16-16 NPK-ratio, or equal, you have a chance to grow plenty of olives.

Is It Safe To Eat / Consume Olives?

Studies show us that olives are beneficial for our heart and might even protect us from osteoporosis. The plant is high in vitamin E and contains antioxidants, so we shouldn’t be surprised that it has the benefits we mentioned before. But even though it has many health benefits, there must be some downsides, meaning it can’t be safe for everyone, can it? Let’s find out!

Pregnant And Breastfeeding Women

When you are pregnant, olive oil is pretty healthy for you to eat, which means that you can add it to your pregnancy diet if you want. For an expectant mother, it has many advantages. First of all, it’s beneficial for the baby and, of course, for you, the mommy.

Children

You can feed your baby with olive oil, but I highly recommend that you do that only once your kid is old enough. This is usually the same age when your kid is ready to start solids.

If you are wondering why you should give your child food containing olive or oil that we talked about earlier, hear me out. Olives have plenty of omega acids and vitamins. In short, these are all critical for the healthy development of your child.

People With Allergies

Even though an allergy to olives is a rare one, it’s not wholly impossible. But, I need to calm down your fear a little bit by telling you that the odds are that you are allergic to the olive tree pollen than the fruit itself. With all this in mind, it’s still advisable to be careful with this fruit if you are allergic to the pollen.

People With Diabetes

As we know, olives are fruits that don’t contain sugar, and what’s more, studies show that they can help you control blood-sugar spikes with the compound they contain called oleuropein. So, the answer to the question, are olives safe for people with diabetes? The answer is yes!

Pets

The short answer is that your pets can eat olives, and the good news is the many minerals and vitamins they contain. But, your pets might never need them if their diet is already satisfactory. They work as a random snack, but I wouldn’t add olives to their regular diet because they might cause your pets some digestive issues.

Featured image credit – © avdeyukphoto – stock.adobe.com

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