How to olives grow?

Classic Trees, Professionally Grown

Frequently Asked Questions

Are they green olives or black olives?
Do your trees make table olives or oil olives?
How long before I get fruit?
How do I process the fruit?
How much fruit can one tree bear?
Can they be grown in cold climates?
Is it true that olive trees need to be kept dry?
Can olive trees be grown in South Florida?

Are they green olives or black olives?

Green and black olives on the same branch
That’s a matter of ripeness. All olives left on the tree will eventually ripen to black. Olives can be pickled at any stage of ripeness. “Green ripe olives” are picked at a certain stage of development, when the juice inside turns from clear to milky. Olives to be used for oil are usually left on the tree until at least some color change has occurred. “Black ripe olives” can be ripened on the tree or picked green and turned black in processing, as with “California Black Ripe Olives.” See the link below at the question “How do I process the fruit?” for recipes for home processing of olives.

Do your trees make table olives or oil olives?

Wherever olives are grown, almost any cultivar of olive is used for both table fruit and oil. References to a particular cultivar’s purpose is generalized and refers to the primary commercial purpose of the cultivar. The exception to the rule is a few cultivars that produce very little oil and so are generally used only as table fruit. A large percentage of the Egyptian cultivars fall into this category.

How long before I get fruit?

That is a function of cultivar. ‘Arbequina’ and ‘Koroneiki’ begin fruiting at an early age (about 3 years). Other cultivars do not make fruit until they are five to twelve years old. Most olive cultivars will not produce fruit without a pollinator tree of a different cultivar. There are also non-fruiting cultivars of olive. Olives grown from seed may never produce fruit and, if they do, will not likely have the same characteristics as the parent tree.

How do I process the fruit?

Olives soaking in brine
Olives are ripe enough for green pickling when the juice inside is cloudy instead of clear.
The following article from the University of California at Davis describes some of the many ways to process both green and black ripe olives at home:

How much fruit can one tree bear?

Arbequina fruit Semi-dwarf varieties typically bear around 30 or 40 pounds of fruit per year at maturity. Larger cultivars such as ‘Mission’ can bear up to 100 pounds of fruit in a season, and the giant ‘Chemlali’ can produce nearly a ton of fruit in one year.

Can they be grown in cold climates?

Some people do grow olives in places where winters are very cold but they take extreme measures to protect their trees from low temperatures. Those who attempt to grow olives in pots to be brought indoors in winter often fail. Olive trees are very demanding of light and potted trees must be up-potted at least once each year or else treated as a large bonsai tree.

Is it true that olive trees need to be kept dry?

Absolutely not. Olive tree culture is much the same as for any tree. Though drought resistant after they are thoroughly established, olive trees need a lightly moist but not soggy soil. Under-watered trees will not grow to their potential and may not fruit. Florida’s porous sand does not hold water and olive trees can stress quickly during drought conditions. Olive trees grown in containers will need frequent attention to avoid overly dry soil conditions.

Can olive trees be grown in South Florida?

Yes, they can grow well there but are unlikely to fruit because the weather is too warm for olives to achieve the dormancy required for flower development.

Olive Pit Propagation – Learn How To Plant Olive Pits

Have you ever wondered if you can you grow an olive pit? I mean, you can grow an avocado from a pit so why not an olive? If so, how do you plant olive pits and what other olive seed info might be useful?

About Olive Pit Propagation

Yes, you can grow an olive pit, but there’s one caveat – it has to be a “fresh” pit. By this, I mean not a pit from a store bought olive. The olives that we eat are treated with lye, among other things, and are unlikely to engender olive pit propagation.

Oh, by the way, did you know that both green and black olives are the same. The only difference is when they are picked. Green olives are picked before ripe, while black olives are allowed to ripen on the tree.

Olive Seed Info

Olive trees (Olea europaea) grow in areas of long, warm summers and mild winters and can be grown in USDA growing zones 8-10. Olive trees are primarily grown from cuttings but growing olive trees from pits or seeds is also possible.

The pits need to be thoroughly cleaned and processed to break dormancy and facilitate germination. When growing olive trees from pits, keep in mind that the germination rate is frustratingly low, so hedge your bets by planting multiple pits. Wondering how to plant olive pits? Read on.

How to Plant Olive Pits

The first step in growing olive trees from pits is to gather seeds in the fall once the fruit has ripened but before they turn black. Don’t gather the olives from the ground but rather harvest the fruit directly from the tree. Use only olives that are unmarred by insect holes or other damage.

Put the olives in a bucket and lightly hammer the flesh to loosen it. Cover the crushed olives with water and soak overnight, stirring the water on occasion. Skim out any floaters, which are likely rotten. Drain the water. Using two scouring pads or the like, rub the olives to remove any residual flesh and then rinse them thoroughly.

Carefully, nick the pointed end of the olive pits with a pair of bolt cutters. Don’t break all the way through the hull or the seed will be ruined. Soak them for 24 hours in room temperature water.

Now it’s time to sow the olive pits. Use a well-draining soil mix of half sand and half seed compost in individual 6-inch containers. Sow the olive seed to a depth equal to two times their diameter. Put the pots into a shaded cold frame with a germination mat set at 60 degrees F. (15 C.) for about a month. Keep the top 2 inches of each pot moist while the seed germinates but allow the top ¼ to dry out between waterings to deter fungal and bacterial disease.

Increase the germination mat’s temp to 70 degrees F. (21 C.) after the first month of warm stratification and continue to water as before. Seedlings should emerge in this second month. When they do, begin to drop the temperature of the mat by 5 degrees each week until the temp is equal to the exterior temperature.

Acclimate the seedling to outdoor conditions gradually over the course of a couple of weeks. Keep them in a lightly shaded area during the hot summer months and then transplant them in mid-autumn when the weather is again cool and moist.


Think of olive trees and you may think of the Mediterranean, but did you know that you can grow olives in Florida? These fruits have a rich history—from appearing in ancient mythology to the peaceful symbolism of an olive branch.


The olive tree (Olea europaea) is an evergreen native to the Mediterranean, Asia, and Africa. The beautiful silvery foliage will vary in color, but is generally considered to be grayish-green. White flowers appear in April or May in Florida and precede the fruit set.

Olive fruits start out as green and will generally become a blackish-purple color when fully ripe; though some varieties will remain green and others turn a copper-brown color. The shape, size, and flavor characteristics can vary quite a bit as well.

Olives are usually too bitter for eating right off the tree; depending on the variety, some are ideal for preserving and eating later, while others are better suited to be pressed for oil.

Planting and Care

Several other Florida plants are commonly called “olive,” so be sure you’re purchasing a European olive tree if you intend to grow an edible fruit.

While olives have been grown in Florida for years on a small scale, they are a relatively new commercial crop here, so there is still much to be learned about the cultural requirements for keeping healthy and productive trees. Researchers have been testing olive trees as far south as Orlando. Growers further south will have to decide whether it’s worth the chance or wait for more research to be done to see just how far south these trees will grow and thrive.

Floral development (and thus, fruit production) in the olive can be quite complex. Planting more than one cultivar close together may increase fruit set. If you want to jump in and give it a try, the cultivar ‘Arbequina’ from Spain has been the most popular in Florida. It is a self-pollinator, meaning it can use its own pollin to fertilize and produce fruit, but having other cultivars nearby seems to help. ‘Koroneiki’ and ‘Arbosona’ are often planted to support pollination of ‘Arbequina’. ‘Mission’, the common black “table olive” (for eating as opposed to those better for oil), is another cultivar that is self-fertile and may do well in a Florida landscape.

One of the most important landscape considerations for growing olives is soil. Olives grow best in sandy, well-drained areas. The trees actually thrive in poor soil; excessive nitrogen fertilization can cause too much shoot growth at the expense of fruit production. Too much water from irrigation or rain will make trees susceptible to root-rot disease and damage production by causing flowers to drop before they form fruits.

Plant your olive trees in a sunny spot with well-drained soil. Once established they’ll require minimal care, but you will need to protect them if winter temperatures drop below 20 degrees.

Pruning can be tricky. Olive trees never bear fruit in the same place on a stem, so new growth each year is essential for flower production and fruiting. While pruning controls height or form and increases airflow to reduce fungal disease issues, the impacts on flowering and fruiting should be considered before drastic pruning takes place.

You should begin to see fruit on your olive tree after three years. In terms of production, don’t be surprised if your tree seems to take every other year off. Olives are described as alternate-year-bearing species and typically have a year of heavy fruit production followed by a year of lighter production. Take advantage of the lower-producing years by pruning non-flowering branches during the flowering season. When heavier fruiting does take place, thin the crop of olives to two to three fruits per foot of twig. This will increase fruit size. Thinning should be done soon after fruit set.

Olives are considered relatively pest- and disease-free trees, although scale can be a problem, as with many other landscape trees in Florida. Additionally, leaves can be damaged by caterpillars and grasshoppers. Keeping an eye on your tree and addressing any issues early is important to keep it healthy and thriving.

For more information on growing olives, contact your local county Extension office. And look for updates from the Florida Olive Council; it’s working with UF/IFAS on olive research.

UF/IFAS Publications

  • Olives for Your Florida Landscape
  • Pests and Fungal Organisms Identified on Olives (Olea europaea) in Florida

Also on Gardening Solutions

  • Mediterranean Gardens

Elsewhere on the Web

  • Florida Olive Council

NOTE: Propagation should be done after the fruit has set and from a parent tree of 3 years or older.

Fill an 8-inch nursery pot with a mix of sand and peat. Completely saturate the mix with water but press out excess water. Poke a hole 3 – 4 inches deep in the center.

Cuttings should be from the tip of a healthy olive branch and about 7 – 8 inches long. Choose one with a 1/4-inch diameter. Sever or hammer it to crack it 1/8 inch below a leaf node. Remove all the leaves except a few on top.

Dip the cracked end in 0.2-percent IBA rooting hormone and gently tap to remove the extra. push the cutting into the hole in the moistened sand mixture and press the soil in tight around it. (Be sure to get the proper concentration there are 3 grades. Be sure to follow the instructions there are health and environmental hazards associated with this product.) The powder has been proven to work better than the gel. Be sure to use plastic gloves.

Place the pot on a propagation mat inside a lightly shaded area and set the temperature on the mat to 70 degrees Fahrenheit.

Mist the foliage twice daily with a spray bottle. Be sure to check the soil, it should be stay moist.

After three months there should be roots on the base of the olive cutting, you can check by gently tugging on the cutting. Continue watering and caring for your new sapling with the heat off, can be placed into a larger pot or planted.

Good Luck!

Rooting olive trees for organic farming

Figure 1: Olive cuttings of the Cornicabra variety of 15 cm with two pairs of leaves rooting in perlite substrate. Credits: Ana Centeno and María Gómez del Campo

Researchers at UPM have shown good results by using products that facilitate olive tree rooting and are authorized for organic farming.

After the enactment of organic farming regulations, there have been significant limitations to the use of certain products for rooting olive trees. Researchers from the School of Agricultural Engineering and School of Agricultural Technical Engineering of Universidad Politécnica de Madrid have taken an important step towards finding solutions thanks to the “Orgánico Terrabal” product that is permitted in organic farming and can be an alternative to the most popular rooting product for olive trees, indolebutyric acid. According to the regulation (CE) 834/2007 and 889/2008, indolebutyric acid is not permitted for organic production.

Organic farming aims to obtain the highest quality products which are respectful to the environment and can preserve soil fertility by avoiding using synthetic chemicals. Organic olive groves comprise the second-most important organic farms worldwide after coffee. Spain has more than 168,000 hectares (MAGRAMA 2012) of organic olive grove, representing 31.1 percent of the total global area. Castilla La Mancha has 38% of the organic olive grove surface in Spain. Andalucia has 33% and Extremadura 19%. It is estimated that 11.5 million kilos of organic olive oil were sold in 2012. This means an increase of about 17% compared to the year before. Italy is the main exporter of Spanish organic oil with 4 million kilos.

Today, olive tree multiplication is performed by semi-hard wood cuttings comprising stems of 20 cm with leaves (Figure 1). The base of cuttings is treated with products that facilitate the rooting and the root formation. After that, the cuttings are placed into a greenhouse on basal heated benches with filled substrate trays and are watered with intermittent misting (Figure 2) in order to maintain humidity and trigger the rooting.

Figure 2: Basal heated benches where the cuttings are placed for rooting. The bench base has a heating system to keep the temperature constant at 24 °C. Cuttings are watered with intermittent mist to keep temperature at 80-90%. Credit: Ana Centeno and María Gómez del Campo

Indolebutyric acid (IBA) is the most popular product in traditional agriculture to trigger the rooting of cuttings. This component belongs to the group of growth regulators. This product does not generate phytotoxic effects and it usage is relatively simple. It is essential to regulate the immersion time of cuttings. However, after the enactment of organic farming regulation (EC) No 834/2007, 889/2008, the products mentioned before are not permitted for producing organic materials.

In order to find alternatives to IBA for production of organic olive cultivars, researchers from UPM conducted two tests at the nursery of the Centro de Transferencia Tecnológica “La Isla” of the Madrid Institute for Research and Rural Development in Food (IMIDRA), located in Arganda del Rey.

Olive cuttings of 15 cm with two pairs of leaves of Cornicabra variety were prepared for the first test. Researchers performed the rooting on a basal heated bench and maintained the olive cuttings at 24 degrees and a constant humidity of around 80-90 degrees through fogging.

Figure 3: Effect of the treatments with yeast and Terrabal Orgánico in the formation of the root cuttings. Rooted cuttings on the right side and non-rooted cuttings on the left. Credit: Ana Centeno y María Gómez del Campo

The cuttings were divided into several groups and each one was treated with a different product. The products tested were indolebutyric acid (to compare the effectiveness of the other products), algae extracts and yeast (that provide nutrients and have hormones), organic sunflower seeds (that when germinating produce promoting hormones for rooting) and two authorized commercial products for organic farming, Sm-6 Orgánico (seaweed extract) and Terrabal Orgánico (a nutritive product for plants from cereal extracts).

After two months, the cuttings of the basal heated benches were extracted and researchers quantified the rooting percentage. The best results were obtained with the Sm-6 Orgánico product and Terrabal Orgánico product (Figure 3). Thus, the following year they conducted the same test with only these two products and assessed the diverse dipping times of the cuttings. The best root formation was achieved with the Terrabal Orgánico product by dipping the cuttings for an hour.

This result led to the conclusion that this product could be an alternative to IBA since it can produce an organic olive plant with a similar percentage of rooting to IBA. However, dipping time of the cuttings requires regulation, because the longer the immersion, the less the percentage of rooting cuttings.

Explore further

Olive oil more stable and healthful than seed oils for frying food More information: Centeno Muñoz, Ana y Gómez-del-Campo, Maria (2008). “Effect of root-promoting products in the propagation of organic olive (Olea europaea L.) nursery plant.” Hortscience, v. 43 (n. 7); pp.. ISSN 0018-5345. Journal information: HortScience Provided by Universidad Politécnica de Madrid Citation: Rooting olive trees for organic farming (2014, November 5) retrieved 1 February 2020 from This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.

If you believe that it’s inconceivable for a lawsuit to hinge on a plate of olives, it turns out that you’re completely wrong. That’s because a Montreal man is threatening to sue a local Turkish restaurant because there were olives with pits on the table. As Eater Montreal points out, there’s a precedent for this sort of thing: Former US Representative Dennis Kucinich sued the House cafeteria (and successfully settled) over a similar olive pit complaint in 2011.

The argument in both instances in the danger and possible dental damage olive pits present to the unknowing.

But what about the true issue here? Pitted olives are completely gross and don’t belong on any table at any time.

Let’s consider the olive for a second. Pits give olives their firm structure. With them, they’re the shimmering highlight of charcuterie and meze platters. Without the pits, olives are a briny, saggy mess. They become a deflated, literal shell of their former selves and belong virtually nowhere.

Pitted apologists may argue that the act of removing the pit while eating is “a pain” or “gross,” but it’s nowhere near the level of discomfort and disappointment experienced when you bite into an olive expecting its natural, pit-filled self.

Worried about etiquette at the table? There are, literally, entire message board threads dedicated to the topic.

If you have a jar of pitted Kalamata olives gifted to you in a holiday basket, yes, feel free to load up on them in martinis and bloody marys. But if you have your choice, do yourself (and the olive, really) a favor and opt for the pit.

Burning Olive Pits

The largest olive processor in theU.S. used to pay to truck around 13 billion olive pits per year to landfills. But the Musco Family Olive Co. now burns what was previously viewed as a waste material to both treat their wastewater and generate electricity to run their plant.

In 2007, after being hit by the state with large fines for water discharge violations, the Tracy, CA-based company began testing a demonstration-sized renewable energy wastewater system (RENEWS) produced by Combined Solar Technologies,Pacific Grove, CA,that proved capable of cleaning the olive plant’s wastewater containing salts, olive brine, olive oil, acetic acid, and high amounts of total dissolved solids.

The firm’s system begins by feeding pits into burners where they are combusted. Energy from the burner heats a heat-transfer fluid made from white paraffin low-grade cooking oil that travels through pipes to a brine boiler. The CST boiler processes the wastewater using a distillation process, and pressurized steam produced from the wastewater powers a steam engine to generate electricity, which is fed into the facility’s power distribution network. Exhaust heat is used to dry solids separated from the wastewater stream.

Since installing a full-scale sized system in 2010, Musco has been able to treat its wastewater and generate 500 kwh/hr, or half of the plant’s electrical needs for operations such as sorters, canners, pitting, packing, and labeling machines.

Storing and Delivering Pits for Combustion

Olive pits have an energy rating of 8,800 Btu per pound, higher than hard wood, and have a similar moisture level. The full-sized system currently in use at the Musco plant burnstwo to threetons of olive pits every hour.

Pits can be burned straight out of the plant, and there’s an easy screw feed system to get them fired in the combustion unit at a constant rate,” explains Frank Schubert, creator of the Bio-Reactor Burner (BRB) and RENEWS at CST.

Pits are fed into a silo for storage before feeding into a burner, and are even used slightly wet. Schubert says the pits are not saturated; about half of the moisture is on the outside in their wrinkles and folds. On occasion pits will be left to dry in the sun, but after scaling to the full-sized plant, CST developed a system to catch the 50-60 gallons per day of water that drained out of the silo so it could be treated with the mill’s wastewater.

Olive pit processing equipment. Photo courtesy of

Pits are fed into a relatively low-temperature combustion chamber where air is spun in a unique way. Ash is allowed to remain in the burner longer at temperatures lower than other typical systems, creating a carbon sink that holds in heat, sulfur and nitrogen oxide. The pits don’t smolder; they start firing quickly when they hit the bed, and burn at 1,800-2,000 degrees F.

As batches of 100 tons are combusted weekly, about one-half ton of residue is cleaned out of the burner.About half of that are “clinkers,” heavy rock-like chunks that look like lava. The other half is powdery fly ash that contains nitrates, potassium, magnesium, and other minerals. Both are spread on the olive fields, offsetting about one-quarter of the facility’s fertilizer needs.

As of 2011, Musco’s CST burner has passed California’s strict air quality laws and is “officially the cleanest burner in California,” producing lower than required limits for nitrogen oxides, according to Schubert.CST’s “bioreactor” combustion unit was granted a permit to emit 17.5-ppm levels of NOx and regularly beats it at 4.7 ppm, according to Schubert.

In addition to treating wastewater, the RENEWS system saves charges for fertilizer, waste disposal, fuel, and power, and generating power onsite reduces transmission and distribution losses.

Musco plans to double the size of its current system this fall, which will provide them with 100% of the plant’s electricity demand.

Debbie Snidermanholds an MENG from Cornell University, Ithaca, NY. She is an independent writer and regular contributor to Mechanical Engineering.

Pits can be burned straight out of the plant, and there’s an easy screw feed system to get them fired in the combustion unit at a constant rate.Frank Schubert, creator of the Bio-Reactor Burner (BRB) and RENEWS at CST

Whether you primarily eat them with martinis or sprinkle them on your pizza, olives make just about everything taste better. But while you might consider that tapenade a savory treat, the flavorful Mediterranean delicacies have another hidden side: They’re technically fruits. Just (carefully) pop any unpitted olive into your mouth for proof.

The stones inside act as the seeds for the Olea europaea tree. In any botanist’s book that means they’re technically classified as fruits — specifically a kind called drupes, a.k.a. stone fruits. This category also includes sweeter produce like mango, dates, apricots, cherries, nectarines, peaches, and plums, but botany doesn’t rely on taste to make distinctions.

The Best Olive Recipes

It all comes down to the reproductive body of the plant, or in this case, tree. According to Encyclopedia Britannica, a fruit is “the fleshy or dry ripened ovary of a flowering plant, enclosing the seed or seed.” Plant an olive pit in the ground and what’ll you get? A slow-growing but surprisingly hardy tree.

For the record, any other edible part of the plant — like the roots (carrots) or leaves (lettuce) — count as true vegetables, but other seed-filled “veggies” like cucumbers, tomatoes, pumpkins, avocados, and even pimento peppers also belong to the fruit family.

If you olove these fun facts, get this: Both green and black olives grow on the same tree. The depth of color reflects the maturity of the fruit at the time of harvest, with green and yellow occurring at the beginning of the ripening cycle and purple and black happening at the end.

You wouldn’t want to eat an olive fresh from the grove though. Without curing and fermenting, a bitter phenolic compound called oleuropein makes the tiny fruits unpalatable. No matter what you call them, it’s a good idea to keep snacking on Kalamatas and drizzling that olive oil.

“Olives are chock-full of monounsaturated fatty acids, a type of fat linked with lowering LDL (“bad” cholesterol) while maintaining HDL (“good” cholesterol”),” says Jaclyn London, MS, RD, CDN, Nutrition Director at the Good Housekeeping Institute. “Plus, long-term evidence suggests that people who consume extra-virgin olive oil daily are at a lower risk of heart attack, high blood pressure, and cardiovascular mortality than those who don’t.”

Cheers (with martinis!) to that.

Caroline Picard Health Editor Caroline is the Health Editor at covering nutrition, fitness, wellness, and other lifestyle news.

Nocellara Del Belice – Castelvetrano Olive Tree

Nocellara Del Belice – Castelvetrano

There really is no other olive like the Nocellara Del Belice or Castelvetrano Olive Tree! This native Sicilian olive tree offers meaty fruit with a uniquely nutty and buttery flavor, making it one of the most sought after varieties in the world. Grown in Western Sicily’s Valle de Belice, the table olive is also known as Castelvetrano, named for the town in which the fruit is traditionally salt brine cured.

The medium sized fruit boasts a high flesh to pit ratio (85-88%), and good weight (5-7 grams). Table fruit is harvested green for best curing. As a dual purpose olive, fruit can be harvested at the rosy blush color stage to produce olive oil well known for its special quality and dynamic flavor profile. Trees are adaptable to most soils and container growing. The tree is hardy and fully appreciates a good heat wave in summer, while sensitive to over-watering. The dense crown of this medium sized (20 feet) tree offers good productivity on lush branches with broad leaves that are darker green in color than other olive tree varieties. They will produce as a single tree, but does even better with another tree of the same or other variety present. Zones 8-11

Growing Info

Latin Name: Olea europaea
Site and Soil: Olives like a warm, protected location with 1/2 day to full sun and well drained soil.
Pollination Requirements: Nocellara Del Belice is self-fertile, though crops will likely be heavier with another variety nearby. Olives are wind pollinated and should be planted no more than 20 ft. apart. You can assist pollination by moving pollen from flower to flower with a small brush.
Hardiness:Nocellara Del Belice is hardy to 10° F. or below.
Bearing Age: 1-2 years after planting
Size at Maturity: Up to 20 ft. in height
Bloom Time: May
Ripening Time: October
Yield: 20+ lbs.
Pests & Diseases: Our Olives have not been bothered by pests or diseases
USDA Zone: 8-11
Sunset Western Zone: 8, 9, 11-24, H1, H2
Sunset Northeast Zone: Not listed

Leave a Reply

Your email address will not be published. Required fields are marked *