Olive trees are beautiful, evergreen trees with a unique twisting bark that adds beauty and interest to the home or landscape. Tree maintenance can be tricky though, and you may be struggling to figure out how and when to prune your olive tree.
There are steps to take to prune your olive tree. First , you should wait until the tree is four years old before you even think about pruning!
You should prune your tree in late spring or early summer before it flowers. Make sure to use the right tools, make clean, correct cuts, and prune to thin the middle section of the tree to let in more light.
While this sounds like a lot, pruning really is a simple process, and going in with the right tools and knowledge will help you to grow a beautiful tree and maybe even produce some olives.
Keep reading to learn about these eight simple steps to pruning your olive tree.
What Defines An Olive Tree?
Olea europaea, or the European olive tree, is a beautiful fruit-bearing tree that originated from Asia Minor, including the Mediterranean and parts of Asia and Africa. The olive tree has been cultivated by humans over centuries to produce food and medicine and has existed in the region for over 6000 years.
The olive tree can grow up to 20-30 feet tall outdoors, and is drought tolerant when mature. They grow best in zones 8-10 and can tolerate some freezing, but prefer a warmer climate and a place in full sun.
For a full timeline on olive trees, check out our article all about olive tree growth.
North American Olive Trees Do Not Produce Fruit
European olive trees should not be confused with North American olive trees that do not bear fruit and are strictly ornamental. Fruiting olive trees will produce fruit in alternating years, with large harvests one year followed by years of lower production.
Another important fact is that olive trees will not produce fruit from the same place on the stem, meaning pruning will be an important tool if your goal is to produce fruit on your tree.
Indoor Olive Trees Require More Maintenance
Olive trees do not typically grow well indoors. While they can survive many years in a pot, eventually you might want to think about moving your olive tree outdoors where it can be planted directly in the ground.
Olive Tree Production Needs Balance
One reason for this is that olive tree production, like other types of trees, depends on the balance between the canopy and root system. An indoor olive tree is constrained by the size of the pot, restricting how much the roots can grow.
Since tree roots do the important job of delivering nutrients to the branches, leaves, fruit, and flowers, this restriction could prevent the tree from getting enough nutrients to produce fruit at all when indoors.
Olive Trees Need Well Draining Soil
Olive trees prefer very well-draining soil and little moisture. Olive trees are particularly susceptible to root rot and other moisture-related ailments, so make sure to avoid overwatering an indoor olive tree.
Prune Your Indoor Olive Tree
Pruning your indoor olive tree will be important to contain it from growing too large in your home. Place the tree in a well-lit window where it will receive eight to ten hours of direct sunlight and consider heading your tree to contain its height (more on this later!)
For more information, check out our article on pruning olive trees in pots!
Ingredients For A Healthy Olive Tree
For a healthy olive tree, try to mimic the environment it is native to. This means choosing a location for your tree that has sandy or well-draining soil, direct sunlight without competing trees nearby, and a moderate amount of rainfall or watering.
Indoors, this means a large pot with very well-draining soil, a place next to a south-facing window that gets eight to ten hours of direct sunlight, careful pruning, and occasional fertilizers and soil amendments.
Keep in mind that too much fertilizer can actually contribute to excessive shoot growth, causing your tree to focus on adding branches rather than producing flowers and fruit.
Keep your tree’s soil consistently moist but not overwatered, and finally, learn how and when to prune the tree to stimulate growth, let light in, control size and shape, and achieve the aesthetic look you prefer.
For more information on watering, check out our article about watering olive trees.
What Is Pruning And Why Do We Do It?
Pruning is an important skill for anyone who is growing or caring for a tree. Olive trees have evolved over centuries with humans and are used for food production, medicine, and cultural and religious significance. As a result of this coevolution, olive trees require careful pruning to produce and flower.
The University of Georgia describes pruning as an “invigorating process.” What they mean by this is that pruning wakes up the mechanisms in the plant that cause it to grow. This growth will be focused on the location where you make a cut, as the plant rushes resources to heal that area and rebalance the canopy in relation to the root mass.
Two Types Of Pruning That Can Be Done To Your Olive Tree
There are two types of pruning categorized as thinning or heading cuts. These two methods will stimulate different regrowth patterns in your olive tree.
Heading cuts will stimulate more branching, leading to a bushier, fuller tree, while thinning cuts will stimulate less new growth and instead will allow light to reach deeper into the plant, and as a result the tree will generate more fruit.
Now that you understand the basics, let’s dive deeper into the art and science of pruning, with eight simple steps you can follow for a healthy and productive olive tree.
Without further ado – let’s get to some steps to pruning an olive tree!
Don’t Prune A Young Tree
The first step to pruning your olive tree is actually not to prune it at all- within the first four years that is! Young olive trees are still trying to become established, and putting all of their energy and resources into getting a solid foundation in the world.
Leave your young olive tree alone until it is at least four years old. Because a young olive tree is reliant on its foliage for photosynthesis, leaving as much on as possible is ideal for a young and hungry tree.
Focus instead on providing the right environment, and plenty of water, and let it do its thing while it becomes established. Pruning too soon can ultimately stunt its growth or cause an infection that the young tree isn’t able to recover from.
Prune Your Olive Tree At The Right Time
Olive trees bear flowers and fruit in the late summer, and are ready for harvest sometimes as early as September, but more generally in late fall, November and even December. This is because the olive fruits take a long time to ripen on the tree, transforming from a light green to a dark, almost black color at peak ripeness.
Olive trees are also sensitive to cold, having originated in the warm and temperate Mediterranean region, so pruning them too early in spring or winter could result in freezing or infection in the cut branches.
The best time to prune your olive tree is in late spring or early summer, when there is no longer any threat of frost and before the tree begins to flower.
Prune Your Olive Tree In Alternating Years
Earlier, we discussed how olive trees are productive in alternating years. This means that the tree will produce a lot of fruit every other year, taking a full summer to devote more resources to growing branches and foliage.
To avoid taking energy away from fruit production, prune your olive tree on its off year. Because pruning redirects energy to branch and shoots growth, this timing will align with the tree’s natural cycles.
On years when your olive tree is producing fruit, keep the pruning to a minimum. Remove suckers from the main trunk and remove any dead or diseased branches, but leave the rest alone.
Define Your Goal
Before you even make your first cut, establish what your goal is for the tree. Consider whether you want to encourage more growth, thin branches to allow in more light, or reduce the height or width of the tree.
In pruning basics, we talked about the two types of pruning, and this is where you can put that knowledge to work.
Using Heading Prune To Prune Your Olive Tree
A heading prune means that you cut the leading stalk or trunk. When you do this to a branch, it encourages it to branch off and become fuller at the cut, resulting in a fuller, bushier tree. You can do this to stimulate the olive tree to fill in large gaps in the foliage.
When you head the main trunk of the olive tree, you will effectively reduce its height. Trees grow from the top, so by heading the trunk, you prevent the tree from growing taller. You may use this type of cut if you are keeping your olive tree indoors or if the tree is at risk of growing into a power line or other height restraint.
Using Thinning Prune To Prune Your Olive Tree
A thinning prune will stimulate less growth than a heading prune. You can prune large branches off of the main trunk, or off of leading branches to open up more space in the tree for light to reach. This type of cut is helpful if you want to encourage more fruit production.
Olives need sunlight to grow fruit, so failing to thin will eventually cause all of the fruit to grow in the upper canopy, where the light can reach, but you will probably have trouble reaching this area yourself to harvest.
Use The Right Tools
Pruning can be physically taxing, especially when making large cuts that require a saw. Using the right tools will set you up for success. First, look at the branches you want to prune, and figure out what the right sized tool is for the job (you may need more than one!)
Pruning Smaller Branches
For younger, smaller branches, you may only need a lopper or pruner, like this Edward Tools Lopper and Pruner Set. These types of tools are great to prune branches up to about three inches in diameter.
Using a pruner or lopper on a smaller branch is great because you can cut off the branch in one clean motion. On a larger branch though, you risk mangling or damaging the branch, which could lead to infection.
Pruning Larger Branches
For these larger branches, move up to a larger tool, such as a handsaw like this Coher Folding Saw. A saw is a better tool to help you cut through larger branches. For the largest branches, you may even need a chainsaw like this Craftsman V20 Cordless Chainsaw.
When using any sharp tool, make sure you are wearing proper safety equipment. Opt for long pants and long sleeves, and don’t wear loose-fitting clothing that could get caught in the blade. Gardening gloves and safety glasses are recommended, especially when using saws that send sawdust into the air, and potentially into your eyes.
Use earplugs when operating a chainsaw and always call a professional if the job is outside of your skillset. It’s better to do it right for the sake of your safety and the health of your olive tree!
Make Clean Cuts
Using the right tool will help you to make clean cuts when pruning your olive tree. Pruning, while good for your tree, is still an injury that your olive tree will need to heal using energy and resources.
Clean cuts are important to ensure that you don’t hurt your tree or invite infection into the tree. Prune the branch as close as possible to its base while avoiding nicking or scraping the leading branch.
Jagged cuts leave more surface area to invite infections into the wound, and larger stumps will decay on the tree. Both of these scenarios will lead your olive tree to send excess energy and resources to the area instead of flowering or fruiting.
Make Sure Your Tools Are Sharp When Pruning
Making sure your tools are clean and sharp is another way to make cleaner cuts. After you use your tools, you should always clean and dry the blade before storing the tools in a clean, dry place where they won’t become rusted or dull.
Regular tool maintenance is a great habit to get into, by either periodically sharpening the blade yourself or taking it to a professional to do so.
Make Correct Cuts
Since you spent time figuring out what your goal was for pruning your olive tree, you are now equipped to make correct cuts. We already discussed the two main types of cuts which are heading and thinning cuts.
Before you get to cutting, see if you can identify the node on the branch. Nodes are the places on the tree where the branch grows from the trunk, or smaller branches from larger ones, or leaves from the branch. The area just above that joint is the node and is the location of specialized cells that will form a new branch if cut.
Making A Heading Cut
Heading cuts will occur at the node between the leading branch and its smaller branches. When you cut the leading branch, the tree will respond by putting out more small branches, making the tree fuller and wider.
This type of cut is good for filling in sparse areas or creating new growth for more flowers and fruit.
Heading the trunk of your olive tree is an extreme form of pruning that will prevent your tree from growing taller. This may be a useful cut for an indoor tree, or one that you want to keep smaller.
Making A Thinning Cut
Thinning cuts are made at the joint between the leading branches and the trunk, or where smaller branches meet the leading one. As its name suggests, this type of cut is made to thin the branches to allow more light in.
Thinning is also a good option for damaged or diseased branches. Brown or spotted leaves and brittle bark and limbs are an indication of an unhealthy branch. Prune these damaged branches to prevent the disease from spreading, and to allow your tree to focus its energy on producing.
Pruning For Fruit And Flower Production
We have discussed the whys and the hows of pruning olive trees, but pruning for production deserves its own spot on this list. Olive trees will begin putting out fruit at around three years old, and are alternate-year-producing plants.
This means that olive trees are very productive every other year, with low production years in between.
In addition, olive trees will never flower or grow fruit in the same place twice. So, it is important to prune your olive tree to encourage new growth if your goal is to increase flower and fruit production.
Tips For Pruning Every Other Year
Prune your olive tree for the first time when it reaches four years old, after its first year of producing olives. Then, try to follow its natural rhythm, pruning more aggressively on slow-producing years, and less on high-producing years.
On the off-years, make your bigger thinning cuts, letting more sun into the inner branches, encouraging production throughout the whole tree instead of just the outer canopy.
In the on-years, before the tree flowers, in late spring or early summer, make heading cuts on smaller branches to encourage new growth to fill out the tree.
Don’t wait for an off-year to cut off dead or diseased branches. It is more important to prevent the ailment from spreading throughout the rest of the tree.
Watch For Pests
Olive trees can be susceptible to damage from pests, especially the Olive Fruit Fly. If your olive tree has become infested with pests, you will want to prune any excessively damaged branches to prevent the spread of flies or related diseases.
Pruning may not be enough in the case of olive fruit flies, so you will likely need other mitigation methods including sticky tape or pest sprays like this Monterey Olive Fruit Fly Trap and Lure.
As always, consult a professional if the infestation is beyond home remedies.
Pruning Lets You Grow A Healthy And Productive Olive Tree
Olive trees offer beauty and interest to your home or garden, and produce beautiful, fragrant blossoms in the summer. They have been cultivated throughout human history, for their medicinal and agricultural use as well as their beauty and cultural and religious significance.
In order to grow a healthy and productive olive tree, learn some simple steps to pruning your olive tree.
These include waiting until the tree is at least four years old, pruning in late spring or early summer before it flowers, using the right tools, making clean, correct cuts, and pruning to thin the middle section of the tree to let in more light.
You shouldn’t be intimidated by pruning, and in fact, once you get the hang of it, it is actually pretty fun! Pruning is an art as much as it is a science, so don’t be afraid of getting creative and making mistakes. You will get more confident with practice, and your olive tree will thank you.
Thank You For Reading!
I hope you have learned some helpful tips and tricks to pruning your olive tree. Pruning can seem confusing to novice gardeners, but it is essential to the health and production of your olive tree. By educating yourself on olive tree pruning, including how to prune, why you should prune, and when you should prune, you are halfway to having a healthy and abundant tree.
To recap what we learned, let’s go over the 8 simple steps to pruning your olive tree:
- Wait to prune your tree until it is at least four years old.
- Prune your tree in late spring or early summer, after the danger of frost has passed and before it begins to flower.
- Define your goal, whether it is thinning to let light in, heading to create more volume, reducing height, or removing diseased branches.
- Use the right tools for the job, and clean and maintain them regularly.
- Make clean cuts, close to the node to prevent injury, disease, or rot.
- Make the correct cuts to achieve the goal you set.
- Keep the natural alternate-year-production cycle in mind to optimize flowering and fruiting.
- Watch for pests and take steps to prevent or eliminate olive fruit flies or other pests.
References:
- Boskou, Dimitrios. (2006) Characteristics of the Olive Tree and Olive Fruit. Chemistry and Technology. 2, 13-19.
- Jiménez-Brenes, F.M., et. al. (2017) Quantifying pruning impacts on olive tree architecture and annual canopy growth by using UAV-based 3D modeling. Plant Methods. 13.55.
- Rapoport, H.F., Fabbri, A., Sebastiani, L. (2016). Olive Biology. The Olive Tree Genome. Compendium of Plant Genomes. Springer. 13-25.
- Rodrigues M.A., et. al. (2021) Use of commercial mycorrhizal fungi in stress-free growing conditions of potted olive cuttings. Scientia Horticulturae. 275.3.
