Olive Tree Root Systems: Invasive or Not? A Variety Comparison

The invasiveness of an olive tree root system largely depends on the size and variety of the tree. 

Large olive tree varieties can potentially have extensive root systems that could cause damage to foundations, paved surfaces, and fences if planted too close. Medium-sized olive tree varieties typically have less extensive root systems. Meanwhile, dwarf olive trees generally do not threaten their roots due to their limited size. 

You can prevent potential damage from their roots by selecting a suitable variety of olive trees and ensuring proper placement during planting.

What Olive Varieties Have Invasive Roots?

Large olive tree cultivars that grow to 30 feet (9 meters) in height or more can potentially have extensive root systems. The roots of these olives can stretch up to 30 feet (9 meters) from the trunk in all directions. 

Common olive tree varieties with potentially extensive root systems include:

• Mission: A large, vigorous variety commonly grown in California. Trees can reach 25 to 30 feet (7.5 to 9 meters) in height.
• Manzanillo: Another large variety that can reach similar heights to the Mission and is well-regarded for its fruit.
• Sevillano: Known as one of the largest olive cultivars, the Sevillano can grow well above 30 feet (9 meters) tall.
• Koroneiki: This variety is native to Greece and is known for its robust growth, often reaching heights of 20 to 30 feet (6 to 9 meters).
• Frantoio: An Italian variety that can also reach up to 30 feet in height, Frantoio is often grown in Tuscany.

While these varieties can have potentially extensive root systems, it doesn’t necessarily mean they are “invasive” in the damaging sense. With appropriate planting and care, they can be successfully grown without causing damage to nearby structures.

So before planting an olive tree in the ground, first, identify the variety of the olive tree. Next, consult with the nursery or grower for information on the mature size of that specific variety.

Also, check out my article on how tall olive trees grow and learn about their height and how to manage it.

What Olive Trees Do Not Have Invasive Root Systems?

Medium-sized olive trees that reach a mature height of 12 to 15 feet (3.5 to 4.5 meters) have less extensive root systems than their larger counterparts. However, these varieties can still potentially cause damage to foundations or pavement if planted less than 10 feet (3 meters) away from a structure. 

Some suitable mid-sized olive tree varieties include:

• Arbequina: This variety is popular among home growers due to its compact size and high productivity.
• Picual: It is another medium-sized variety highly resistant to cold and disease; one of Spain’s most widespread varieties for olive oil production.

 Dwarf olive trees typically do not have extensive root systems. Their relatively small size means their root systems are unlikely to cause damage to concrete structures. They even pose little to no risk to fences and garden walls. Therefore, you can plant dwarf olive trees beside your home or fence without concern.

Some of the best varieties of dwarf olive trees include:

• Little Ollie: A non-fruiting variety, Little Ollie is appreciated for its compact size and dense, silvery-green foliage, making it an excellent option for smaller gardens or landscaping projects.
• Skylark Dwarf: Known for its hardy nature, Skylark Dwarf has a compact size with the bonus of producing small edible fruits.
• Picholine: While not strictly a dwarf variety, ‘Picholine’ is a smaller olive tree manageable in a home garden setting.

Even though dwarf olive trees are compact, they still need proper care and attention to thrive. More about how to grow dwarf olive trees you can read in my post: dwarf olive tree care. 

How Do Olive Tree Roots Grow?

Olive trees are accustomed to harsh conditions, and their roots can grow deep into the soil during drought conditions to find needed water. Yet, in typical situations, you’ll find most of the root system in the top six feet (3 meters) of the soil, spread wide to collect nutrients and moisture efficiently.

Olive trees are known for their slow and steady growth; this rule also applies to their roots. This slow pace can benefit, allowing the surrounding environment and other plantings to adapt gradually.

Overall, the size and spread of an olive tree can provide clues about its root growth. Larger, taller varieties can develop deep, extensive root systems that echo their above-ground stature. Medium-sized trees have a more moderate root spread, while the roots of dwarf varieties keep a low profile, making them great candidates for pots and smaller garden spaces.

Finally, remember that while olive tree roots can be persistent, they’re not invasive or aggressive by nature. They’re not out to destroy your pathways or damage your home’s foundation. With some planning and understanding, you can ensure your olive trees and their roots coexist harmoniously with the rest of your garden and nearby structures.

How Deep Do Olive Tree Roots Go Down?

The deepest roots of an olive tree can reach depths of 23 feet (7 meters) in very loose soil. However, olive trees are generally flat-rooted, and most of the olive tree’s roots grow 10 feet (3 meters) deep in the ground. While it may seem like these roots aren’t digging deep, this is enough to anchor your tree firmly and absorb the nutrients it needs to thrive.

Also, this depth is sufficient to grow underneath a home foundation or driveway. As the roots expand below these structures, they can cause the concrete to shift, crack, or buckle.

If you grow a dwarf olive tree, its root system reaches a maximum depth of 3 feet (1 meter), and they are noninvasive roots.

Note: All measurements are approximations and can vary based on factors like soil type, climate, and the specific variety of the olive tree.

How Wide Do Olive Tree Roots Spread?

While the roots aren’t plunging too deep into the soil, they tend to spread out wide. Olive tree roots often extend as wide as their canopy, sometimes up to 1.5 times its width. What does this mean? If you’re dealing with a full-grown tree flaunting a great canopy spread of up to 30 feet (around 9 meters), its roots can extend outward just as far. 

In the olive family, size matters when it comes to root spread. The large olive varieties, reaching about 30 feet (9 meters) tall, typically boast more extensive root systems. They’re like the big, friendly giants of the olive tree world, with their roots reaching as far as their height.

The medium-sized olive trees, usually capping at a modest height of around 15 feet (4.5 meters), generally have less expansive root systems. These roots can still venture quite a distance from the trunk and reach at least 2/3 of their height and more.

Finally, let’s not forget compact dwarf olive trees. These little guys make a significant impact with their limited root spread. They’re perfect for pot culture or cozy corners near structures. 

Note: ‘Potentially Invasive’ indicates that the root system could create problems if not properly managed. ‘Moderately Invasive’ suggests that the roots have a broad spread but are usually less problematic. Also, the actual behavior of a tree’s root system will always depend on local conditions and the care given to the tree.

Do Olive Trees Have a Lot of Roots?

Olive trees have a vast network of roots. But it’s not so much about the quantity as their impressive reach. The roots of an olive tree, especially the larger varieties, can extend as far as the tree’s canopy.

Imagine the roots as a mirror image of the canopy, except underground. And this will give you a fair estimate of the root network’s extent. It’s not about a multitude of roots but a system that’s spread wide and wisely.

How Strong and Thick Olive Tree Roots? 

Olive tree roots are solid, robust, and strong enough to push through even the toughest soil. This vigor allows them to penetrate even compact and rocky soil, seeking water sources and providing a firm anchor for the tree against strong winds. It’s part of the reason olive trees can thrive in various environments and withstand diverse weather conditions.

When an olive tree is young, it sends down a primary root, known as a taproot, which tends to be the thickest. This taproot can be impressively thick in its youth – we’re talking several inches in diameter here. As the tree grows, however, the central taproot may lose its dominance, giving way to a more distributed root system.

As the olive tree matures, the original taproot develops into a network of smaller yet strong lateral roots. These roots spread out and down into the soil, creating a powerful underground system that anchors the tree and absorbs vital nutrients and water from the earth.

In mature trees, you will often find multiple large, thick roots that provide a solid base for the olive tree. These roots can also be several inches in diameter, comparable to the size of the primary root in a young tree.

Will Olive Tree Roots Damage the Foundation of Your House?

Olive tree roots have a purpose: to search for water and nutrients. Planting too close to a structure, like a house foundation, could cause a stir. They can burrow under concrete, which may cause some shifting and cracking over time. Moreover, they can drink water from the surrounding soil, causing the ground to sink as the water is extracted. The foundation may crack as the ground sinks due to olive tree root activity, and your house may lean towards the tree.

• Olive tree roots could potentially cause foundation damage if the olive is planted too close to your home.
• Dwarf olive trees are an exception — their noninvasive roots won’t cause damage. 
• Full-sized olive trees could cause a foundation to buckle, crack, or tilt. 

How Close Can You Plant an Olive Tree to Your House?

In general, olive trees are not as invasive or aggressive as some other species. If you are growing an olive tree with a height of 30 feet (9 meters) at maturity, ensure it is planted at least 20 feet (6 meters) from your home. This distance gives the tree’s root system plenty of room to spread without causing structural issues.

If your olive tree’s maximum height is around 15 feet (4.5 meters), choose a planting location at least 10 – 15 feet (3-4.5 m) from your home.

If you’re cultivating a dwarf olive tree, you can plant it as close to your home as you like or even in a pot to control root spread completely.

 Use the same distance rules to avoid planting olive trees near paved surfaces and other structures, including driveways, sidewalks, garages, pools, and garden sheds. 

Your olive tree may only be a few feet tall when you first plant it, but some mature trees in the olive family can reach substantial heights. This foresight can help prevent damage and ensure your tree thrives without interfering with your property’s structures.

But what if your space is limited, or you want to create a landscape design with closer plantings? You could plant an olive tree closer to a structure with diligent care and pruning. However, this requires careful monitoring and might mean your tree doesn’t reach its full potential.

Also, check my article about where olive trees grow best.

How Do You Restrict Olive Tree Roots?

While it’s technically possible to use root barriers or similar methods to prevent olive tree root growth from invading foundations, it’s often a lot of work for minimal reward.

Roots are resilient, and strategies to prevent them from growing underneath your house require much time and effort. Furthermore, restricting root growth does not typically lead to healthy, thriving trees. An olive tree with restricted roots may struggle, produce fewer olives, and look unhealthy.

• You can use root barriers and other techniques to halt olive tree root growth. 
• Restricting olive tree roots is labor-intensive and can weaken or kill the tree. 
• Instead of restricting growth, select the right size of olive tree for your yard. 
• Larger trees can be grown in spacious areas, but smaller olive tree varieties are best if the tree must be planted near your house or driveway.

Rather than limiting the growth patterns of your olive tree roots, choosing a suitable olive variety for your available space is generally a better approach. 

In a large backyard, an olive tree with potentially extensive roots can be safely planted at an appropriate distance from your home. In smaller yards, mid-sized or dwarf olive trees are often a better choice.

Suppose you don’t have a large area where your olive tree will receive adequate sunlight, consider growing dwarf olive trees instead of a full-sized tree. Dwarf olive trees can still produce a healthy yield of olives, depending on the variety, and provide a manageable addition to your landscape.

Are Olive Tree Roots Damaging?

The roots of mature olive trees can be extensive, leading to complications if not adequately managed or strategically placed. Olive tree roots can encroach upon foundations, paved surfaces, and pipes, leading to undesirable disturbances.

Olive tree roots tend to spread out rather than dig deep and can reach an expanse wider than the tree’s canopy. So if your plumbing or irrigation lines are in their path, these roots may cause an issue.

Before you go ahead and plant that olive tree near your home, here’s what you need to know about olive tree root systems:

• The roots of mature olive trees can potentially be extensive. 
• Olive tree roots might encroach on foundations, driveways, and sewer pipes. 
• Olive tree roots often spread as wide as or wider than the tree’s canopy. 
• Larger olive tree varieties that reach heights of 30 feet (9 meters) will likely have the most extensive root systems. 
• Medium-sized olive trees that stop growing at 15 feet tall (4.5 meters) have significantly less invasive roots. 
• Dwarf olive trees have roots that are not invasive at all.

Places Where It Is Safe To Plant Olive Trees

Here are some of the best places to plant olive trees:

• Spacious Backyards: Larger olive trees should be planted at least 20 feet (6 meters) away from your home and paved areas to prevent potential root damage.
• Sunny Spots: Olive trees love the sun! Ideally, they need at least six hours of direct sunlight daily. Choose an area in your garden that isn’t shaded by buildings or other trees.
• Hillside Plantings: Olive trees thrive on hillsides, especially those with a south-facing slope. The slope provides excellent drainage, and the south-facing aspect ensures plenty of sun.
• Mediterranean-Style Gardens: Olive trees are a classic element of Mediterranean landscapes. If you aim for a Mediterranean look, your olive tree will feel right at home.
• Large Pots or Containers: Dwarf varieties of olive trees do well in pots or containers. This allows you to control the tree’s size and grow olive trees on patios, decks, or balconies.

Places Where It’s Not Safe To Plant Olive Trees

• Be cautious about planting olive trees near underground utility lines, including sewer lines and irrigation systems. Olive tree roots seeking moisture and nutrients could interfere with these utilities and cause significant damage.
• Olive trees are not the best choice near pools or ponds. Their extensive root systems can damage the structure of these water features, and the constant shedding of leaves and fruit can make maintenance a headache.

Note: these are general guidelines and the specific needs of your olive trees may vary based on your garden’s specific environmental and soil conditions.

Frequently Asked Questions

Conclusion on Olive Tree Root System

Olive Trees have strong but not typically invasive root systems. Their roots stretch far and wide, much like their canopy, and they can dig deep, especially when searching for water in drier conditions. These traits are less about being intrusive and more about securing their hold on the earth and ensuring their survival.

While olive trees are generally not destructive to foundations or infrastructure, their root spread can still be considerable. Therefore, you should give your tree ample space to grow without causing potential issues with structures or other plants. A safe rule is to provide room equal to the expected canopy width, especially for larger olive tree varieties.

So, whether you’re planning an expansive orchard or just adding one tree to your backyard, knowing your olive tree’s expected size and understanding its root behavior can help you avoid unanticipated surprises.

Related Topics

• Olive Tree Lifespan
• Olive Tree Grow Best Conditions
• Olive Tree Growth Rate

Vangelis Kleft

Hi, I’m Vangelis Kleftogiannis, the founder of Oliviada and an established olive oil expert from Kalamata, Greece. My expertise isn’t just in producing quality Extra Virgin Olive Oil, but also in the cultivation and care of olive trees themselves. I am deeply committed to sharing my knowledge and know-how, helping others understand the intricacies of olive tree growing and the creation of quality olive oil.

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