Best Way to Prune Olive Trees: Simple 6-Step Guide

ByBNW TEAM

The olive tree (Olea europaea) is a symbol of peace, longevity, and resilience. While these trees are notoriously hardy, often surviving for centuries in poor soil with little water, they require specific care to reach their full potential. If you want a tree that produces a bountiful harvest of high-quality fruit, rather than just a decorative bush, you must master the art of pruning.

Pruning an olive tree is distinct from pruning other fruit trees like apples or peaches. It requires a balance between encouraging new growth (where the fruit appears) and maintaining an open structure for sunlight penetration.

Below is a comprehensive guide on the best way to prune an olive tree, designed to take you from a novice clipper to a confident arborist.

Why Prune? The Philosophy of the Olive

Before picking up the shears, it is vital to understand why you are cutting. An unpruned olive tree will naturally become a dense, bushy shrub. While this looks lush, it creates a “canopy shadow” where the outer leaves block sunlight from reaching the centre.

The goals of pruning are:

  1. Light Penetration: Olives need sun to ripen. A dense canopy results in fruit only growing on the extreme outer tips.
  2. Air Circulation: Good airflow reduces the risk of fungal diseases like Peacock Spot or Sooty Mould.
  3. Fruit Production: Olives grow on one-year-old wood. Pruning stimulates the tree to produce new shoots this year, which will bear fruit next year.
  4. Harvest Ease: Keeping the tree at a manageable height ensures you don’t need a fire truck ladder to pick your crop.

1. Timing: When to Cut

Timing is critical. Pruning at the wrong time can expose the tree to frost damage or stunt its fruit production for the season.

  • The Best Time: Late winter to early spring. You want to prune when the risk of severe frost has passed, but before the tree begins its new spring growth flush (and before flowers appear).
  • In Mild Climates, you can prune earlier in the winter.
  • In Cold Climates, wait until early spring to ensure the wounds heal quickly with the rising sap.

Warning: Never prune during heavy rain. Moisture on fresh cuts invites bacteria and fungi. Always choose a dry, sunny day.

2. The Toolkit: Preparation and Hygiene

Olive trees are susceptible to pathogens, particularly Verticillium wilt and olive knot. Tool hygiene is non-negotiable.

Essential Tools:

  • Bypass Pruners (Secateurs): For small twigs and branches up to ½ inch thick.
  • Loppers: For medium branches up to 1.5 inches thick.
  • Pruning Saw: For removing large structural limbs.
  • Disinfectant: A solution of 10% bleach or 70% rubbing alcohol.

The Golden Rule of Hygiene: Dip or wipe your blades with disinfectant between trees, and ideally, between major cuts on the same tree if you suspect disease. This prevents you from acting as a vector, spreading infection across your orchard.

3. The Strategy: The “Open Vase” Method

The universally accepted “best way” to shape a productive olive tree is the Open Vase (or Open Centre) system. Imagine a martini glass or a wine goblet made of wood.

The trunk represents the stem of the glass. The main scaffold branches slant outward (the bowl of the glass), and the centre is empty.

Why the Open Vase?

Olive trees are heliotropic; they crave the sun. By removing the central leader (the main vertical trunk above a certain height) and hollowing out the middle, sunlight can strike the inner branches and the ground below. This ensures that the tree produces fruit throughout its entire volume, not just on the “skin” of the tree.

4. The Step-by-Step Pruning Process

Whether you are rehabilitating an old tree or training a young one, follow this logical order of operations.

Step A: The Clean-Up (The 3 Ds)

Start by removing the obvious “garbage” wood. This clears your view and makes the structural decisions easier. Remove:

  • Dead: Any dry, brittle wood.
  • Damaged: Branches broken by wind or animals.
  • Diseased: Wood showing signs of knots, black mould, or lesions.

Step B: Removing Suckers and Water Sprouts

  • Suckers: These are the shoots growing from the base of the trunk or the rootstock. They steal energy from the main tree and are structurally useless. Cut them flush to the ground.
  • Water Sprouts: These are vigorous, perfectly vertical shoots growing from the main branches. They grow rapidly, rarely bear fruit, and shade the centre of the tree. Remove them completely.

Step C: Establishing the Structure (The Open Centre)

If the tree is mature but messy, look for the “central leader”—the main branch going straight up the middle. You may need to saw this out to re-establish the vase shape.

  1. Identify 3 to 5 main Scaffold Branches. These should originate from the trunk at roughly the same height but facing different directions (like the spokes of a wheel).
  2. Remove any large branches that are crossing through the centre or rubbing against your chosen scaffold branches.
  3. The goal is for a bird flying through the tree not to hit its wings.

Step D: Thinning Cuts vs. Heading Cuts

This is where the artistry comes in. You will use two types of cuts:

  1. Thinning Cuts: This involves removing an entire branch back to its point of origin (the larger branch it grew from).
    • Use this for: Reducing density and letting in light. This is the preferred cut for olives.
  2. Heading Cuts: This involves cutting a branch off halfway, usually just above a bud.
    • Use this for: Shortening a branch that is too long or stimulating branching. Use sparingly, as this often results in a burst of chaotic, bushy growth at the cut site.

Step E: Detail Pruning for Fruit

Once the structure is set, look at the smaller branches.

  • The Weight Factor: Olive branches are flexible. As fruit sets, the weight will pull the branch downward (weeping). This is good! The hanging branches protect the fruit from sunburn.
  • Remove “Up” and “Down”: Generally, keep the lateral branches that grow horizontally. Vertical shoots (going straight up) are vegetative and won’t fruit well. Branches growing straight down often get too much shade.
  • Cycling Wood: Remember, fruit grows on the previous year’s growth. If you cut off all the new growth from last year, you will have zero olives this year. Leave plenty of healthy, pencil-thick grey/green shoots.

5. Pruning Based on Tree Age

The Young Tree (Years 1–3)

Objective: Training and Structure.

  • Do not prune heavily. The tree needs leaves to photosynthesise and grow roots.
  • Focus only on establishing the single trunk and selecting the 3–4 main scaffold branches.
  • Remove suckers relentlessly.
  • Tip: Stake the tree if necessary to ensure a straight trunk, but allow some movement to strengthen the wood.

The Mature Tree (Years 4+)

Objective: Maintenance and Production.

  • Follow the Open Vase method described above.
  • Limit the height. If the tree gets too tall, use a thinning cut to bring the top of the scaffold branches down to a lateral branch. This keeps the harvest accessible.

The Neglected Tree (Renovation)

Objective: Survival and Reset. If you inherit a tree that hasn’t been pruned in a decade, do not fix it all in one year. Removing more than 25-30% of the canopy at once can send the tree into shock or cause massive sunburn on the bark (which was previously shaded).

Spread the renovation over 3 years:

  • Year 1: Remove dead wood and the largest central obstructions.
  • Year 2: Select scaffold branches and thin out the density.
  • Year 3: Fine-tune the detail pruning.

When to Call for Backup: While routine maintenance can be handled with hand tools, large-scale renovation often involves removing massive, heavy limbs that pose a safety risk. If the job requires chainsaws at height, or if a tree is too diseased and requires total removal, it is wise to consult experts. Services like Lakeside Tree Lopping and Stump Grinding are equipped to handle dangerous structural removals and ensure that large root systems are ground down properly to prevent regrowth or tripping hazards.

6. Common Mistakes to Avoid

  1. ** The “Poodle” Cut:** Do not shear the olive tree like a hedge or a topiary. Shearing cuts the tips of every branch, creating a dense wall of leaves on the outside and a dead, leafless interior. It looks neat for a week, but ruins fruit production.
  2. Leaving Stubs: When removing a branch, cut just outside the “branch collar” (the swollen area where the branch meets the trunk). Leaving a long stub prevents the tree from healing over the wound, inviting rot.
  3. Over-Pruning: Olives are alternate bearers (heavy crop one year, light the next). Heavy pruning can exacerbate this cycle. Aim for a moderate prune every year rather than a harsh prune every three years.

Conclusion: A Labour of Love

Pruning an olive tree is a partnership between the gardener and nature. You are guiding the tree’s energy, directing it away from useless wood production and toward the creation of healthy, oil-rich fruit.

When you finish pruning, step back and look at your tree. It should look balanced, airy, and slightly “lighter.” Sunlight should dapple the ground beneath the trunk. If you have achieved the “Open Vase” shape and removed the dead weight, you have set the stage for a thriving season.

Remember, the olive tree is forgiving. If you make a mistake and cut the wrong branch, it will grow back. The most important step is simply to begin.

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