Did you know you can grow olive trees in the landscape? Growing olive trees is relatively simple given the proper location and olive tree care is not too demanding either. Let’s find out more about how to grow olive trees.
Growing Olive Trees
Think of olive trees and one visualizes the warm sunny Mediterranean, but olive trees can be grown in North America as well. Most aptly suited to areas which are prone to high heat and plenty of sunshine, the olive tree should be planted outside and once established is fairly low maintenance.
Olive trees have lovely silver leaves, which will compliment many other plantings of the garden but are also grown for their fruit. The olive tree’s fruit can be pressed for oil or cured (brined) and eaten.
There are other plants which bear the name “olive,” so make sure to look for a European olive tree when you are growing olive trees. Some cultivars that flourish here are self-fertilizing ones such as Arbequina and Mission, grown for oil and Manzanilla, which is the typical “California” black olive suitable for canning.
How to Grow Olive Trees
Most olive trees take about three years to come into maturity and begin to set noticeable amounts of fruit. To increase fruit set, it is recommended that you plant more than one cultivar close together.
Olive trees like to be planted in well drained soil in a sunny area of the landscape. The olive tree is an evergreen that flourishes in hot dry areas and as such, will not do well in wet winter soil.
Olive trees are usually purchased in either 4 inch (10 cm.) pots with numerous side branches and a height of 18 to 24 inches (46-61 cm.) or in a 1-gallon pot with a single trunk and a height of 4 to 5 feet (1-1.5 m.). Unless you are growing an olive tree for a strictly ornamental purpose, it is most advisable to plant a specimen with a single trunk for ease of harvest.
Look for olive tree specimens that are actively growing with soft new growth sprouting from the shoot tips. In an olive tree orchard, the trees are spaced 20 feet (6 m.) apart to accommodate their eventual size, however, there is no strict rule of thumb on spacing. Spacing will vary according to the cultivar.
Dig a hole the size of the olive tree’s container. Leave the root ball alone except to remove or cut any circling roots. Do not add soil medium, compost, or fertilizer to the newly planted olive tree. Also, avoid adding gravel or drainage tubing. It is best for the young olive tree to acclimate to its soil.
Olive Tree Care
Once your new olive tree is planted, it is a good idea to provide drip irrigation as the tree will need water every day, especially during the summer months throughout its first year.
Once you begin to see a quantity of new growth, feed the olive tree with nitrogen rich compost, conventional fertilizer, or concentrated organic.
Minimally prune during the first four years, only enough to maintain shape. The young olive tree may need to be staked right up against the trunk to assist with stability.
Commercial olive tree growers harvest fruit in September or October for canning purposes and small fruit is left until January or February and then pressed for oil.
Classic Trees, Professionally Grown
Olive trees require a well-drained soil and a sunny position. Avoid sites where water stands during rainy periods or where ground water seeps into a hole two feet deep. Do not, however, confuse the olive for a desert plant. It needs regular watering to thrive. Insufficient water will cause your tree to suffer, and even die if left too dry for too long.
Choose a site that receives at least six hours of direct sun per day. Full sun is ideal.
Plant your tree at the depth it has been growing in the pot. Do not amend the soil with organic material, moisture-retaining polymers, fertilizer or anything else. Simply plant in the native soil (provided it is well-drained) and backfill with the same.
If your tree requires staking, it will already have a stake in the pot. A very young tree may require a heavier stake as it grows. Once the trunk caliper reaches 1.25 inches or more in diameter (or perhaps less for shrub-form or short trees), it will no longer require a stake. Until then, use a stake large enough to hold the trunk upright. Put the new stake in the same hole the previous stake occupied and tie the tree to the stake with arborists' tape such as comes with your staked tree. Do not use wires, water hoses, cloth, cables, guying systems or other means of securing your tree. A good stout stake and the proper tape is all you need.
Olive trees do not need special olive tree fertilizer but results will be exponentially more satisfactory with a good nutrition regimen. If planting is done after mid-August but before March 1, do not fertilize at the time of planting wait until spring. Otherwise, fertilize after planting and regularly throughout the growing season. How regularly will depend upon the type of fertilizer used. We at Olive Tree Growers prefer to use a premium slow-release fertilizer with essential minor elements (zinc, boron, calcium, etc.). Use a fertilizer that has a nitrogen analysis of at least ten percent. Olive Tree Growers believes that some sort of minor elements package is important, as many soils are lacking in some essential minerals which aid plant growth in several ways.
A fast-release farm-type fertilizer such as 10-10-10 or 13-13-13 may be used according to label directions. Many such fertilizers contain some minor elements and are widely available. Be sure to water very well after application. These fertilizers are generally not for use on plants in pots.
Liquid fertilizers may be used (again, a formulation with minor elements is best) but it should be remembered that liquid feeding is a fleeting thing and must be repeated often.
Organically-derived fertilizers are available and a good thing, though often more expensive and rarely contain the percentage of nitrogen preferred by olive trees. Top dressing with organic material such as composted manure or kitchen compost can be done but the grower should consult the current literature. It can be difficult to achieve a good balance of nutritional elements by this method. It is environmentally responsible but requires more study and understanding by the gardener. Always avoid placing compost or any fertilizer next to the trunk of the tree.
Whatever type of fertilizer is used, it is best to feed lightly and often during the growing season. Avoid heavy applications of fast release fertilizer that could damage plants and leach or run-off into groundwater. Always read and follow label instructions. Do not fertilize after mid-August or before mid- March unless you live in a very warm climate.
If your tree is planted in a lawn area, take care that lawn maintenance practices do not harm the tree. Do not allow "Weed and Feed" products to be used within 30 feet of your tree. These products are designed to feed lawn grasses and destroy other plants. Remember that the roots of any tree extend far beyond the drip-line of the branches. Also, do not allow weed-eater operators near your tree. Weed-eater operators kill thousands of trees every year by "girding," or removing the bark from the bases of trees.
Wood chips are bad, okay? Do not use wood chips, cypress mulch, etc. for mulch. These products are high in carbon and rob the soil of nitrogen and other nutrients in the decomposition process. They also hold too much water in wet periods and, once dry, shed irrigation water and rainfall like a shingle roof. We prefer to use only pine straw for mulch and keep it back several inches from the trunk do not allow a build-up of decomposed mulch around the base of the tree trunk. If pine straw is not available, you can mulch with pine bark or gravel.
Once established, olive trees are among the most drought-resistant trees in the world, but porous soils such as Florida sand are very inefficient at retaining moisture olive trees in sandy soils must be watered often. You will have to water sufficiently to get your tree established and thereafter as necessary during dry periods. No one can give you a formula for that you will have to observe and evaluate. Low volume spray irrigation can be used effectively, but drip irrigation is of little or no use in sandy soils.
Olive trees do not require pruning in order to produce fruit, at least not until they are around 50 years old. It is okay to prune olive trees to achieve a desired shape but remember that they fruit on branches that grew during the previous spring and summer cutting off a lot of such growth will preclude or greatly reduce fruiting potential for the next season.
It may be helpful to prune the top, upwardly growing, branches back by a few inches to encourage lateral growth, thus facilitating the picking of fruit. It is also a good idea to cut out small interior branches that will ultimately clutter the tree's appearance and provide protection for any pests or diseases that may be lurking around your site.
If fruiting is not important, you can shape your olive tree to any way you please.
The only pests we have known to attack olive trees outside of olive producing regions is an armored scale insect. It is not common but should be watched for, especially if your site has other species prone to harbor scale insects. Inspect the trees by looking under the leaves and in the branch axils for a dark bump the size of a "BB." These insects do not move in the adult stage they attach themselves like barnacles. The presence of sooty mold on leaves and bark, or ants crawling on your tree, indicates the presence of scale insects.
If scale is found, it may be treated with a variety of products, depending upon personal preference. It may also be removed by hand if you have only one or a few trees. If you have other plantings that attract pests such as thrips or stink bugs, these may also have a go at your olive tree. Consult your local garden center or pest control specialist about the control of pests. Regulations vary from place to place.
Finally, be sure to keep ant colonies away from your trees.
Smart tip about winterizing olive trees
You’ll increase hardiness of your olive tree in winter by protecting it from wind. Set a lattice up on two sides, forming a corner that will cut the worst of colds winds off.
Credits for images shared to Nature & Garden (all edits by Gaspard Lorthiois):
Olive tree in winter by André P. Meyer-Vitali under © CC BY 2.0
In Homer’s The Odyssey, Odysseus and his indomitable wife, Penelope, set the modern standard for using olive trees as interior decor: the foundation of their bed was carved into the roots of a living olive tree that had grown deep into the hillside where they built their home. And while Homer’s olive tree stood as an exquisite symbol of the couple’s deeply rooted love, if you decide to keep an olive tree in your home, I recommend keeping it in a large pot so you can move it around for optimal decor and plant health.
Of course, if we’re talking about growing olive trees in containers, we know they’re not going to reach mythic proportions. But because most olives are too sensitive to frost to thrive in our region, containers are a wise approach to cultivating them here. Choosing a variety well suited to interior environments, planting it in appropriate soil and pruning it to manage growth and size make growing an olive tree indoors possible — but keeping it alive is a labor of love. No wonder Homer used one to symbolize Penelope and Odysseus’ marriage.
These trees grow in rocky, dry, hot regions with mild winters. The pots they grow in must drain very efficiently, so choose one made of a natural material like terra-cotta or even wood, and be sure to add a good percentage of perlite or expanded shale to your potting soil so the roots don’t rot. Also, keep in mind that trees are not going to produce abundantly if they live inside at all times. In an ideal situation, your tree would be outside during the hot, dry season and indoors during the coldest months, with a daily minimum of six hours of direct sunlight. These containerized trees do well on patios and are commonly grown this way even in their native regions.
Even restricted to containers, size can be an issue when growing trees indoors. Luckily, fruiting olive trees can be kept petite with careful pruning. Pruning is best performed at the end of winter when the tree is dormant and hasn’t yet begun to flower, so you can clearly see its frame. Trim any “suckers” growing around the base of the tree or new growths protruding from the crotches of major branches, and be sure to remove dead wood. The canopy of the tree needs light to reach into the crown for optimal olive production, and major pruning will remove up to 25 percent of growth. Curiously enough, the olive tree will respond by growing more when it is pruned heavily perhaps there’s a Homeric lesson hidden in there somewhere as well.
When you go to invest in your own olive tree, note that buying a year-old, foot-tall tree will typically cost somewhere between $25 and $50. They grow slowly, too, and it will take anywhere from three to five years to see fruit, if you see any at all. Select a tree that has evenly distributed main branches, and avoid or remove crossed branches. It’s best if you can look at the roots when buying a tree. They should spread out evenly and easily when you go to pot the plant, and they should not be growing out of the pot’s drainage holes. Similarly, make sure your pot has ample space for the tree you buy, and pot up appropriately as your olive tree grows so its roots have room to feed the tree.
Olive trees typically require pollinating companions, and multiple varietals are usually carefully arranged in groves to provide optimal fruiting however, the Texas-friendly “Arbequina” variety is self-pollinating. Its fruit can be used for table olives or pressed for oil, if you are so inclined. However, if you simply want the exquisite matte leaves and a piece of the Mediterranean palette to grace your home, there are plenty of decorative varietals from which to choose. They offer a striking contrast to most traditional houseplants and, like Penelope’s, they ultimately symbolize your epic dedication and perseverance.
Written by Sarah J. Nielsen • Photography by Nazar Hrabovyi and the Bialons