My parents are planting a lot of new fruit trees lately, and they’re wondering how far they should be planting from other trees and their house. To help them with this, I did some research. Here’s what I found about fruit tree roots and if they’re invasive or damaging.
Generally, fruit trees don’t have invasive roots, but they can cause damage depending on how close they are to a structure. This risk can be reduced if you plant them at least 25 feet away from structures and choose less invasive rootstocks. Avoid planting the trees near foundations, fences, pipes, and fire hydrants.
So, while most fruit tree roots aren’t invasive, which fruit trees are the most invasive, and how invasive are they? Let’s take a further look.
The Least Invasive and Most Invasive Fruit Trees
Least Invasive Fruit Trees | Most Invasive Fruit Trees |
---|---|
Apple | Avocado |
Apricot | Fig |
Banana | Jamaican Cherry |
Cherry | Java Plum |
Citrus | Jujube |
Papaya | Mango |
Paw Paws | Mulberry |
Starfruit | |
Dwarf Varieties |
Before we jump into the details, I wanted to provide you with a table to separate the least invasive and most invasive fruit trees. Hopefully, it helps a bit.
Keep in mind that while some fruit tree species are more invasive than others, some varieties can also be more invasive. For example, most cherry trees roots aren’t considered invasive, but Jamaican cherry trees can be highly invasive.
Also, figs tree roots are generally one of the most invasive of the fruiting trees.
Now, let’s get into more specifics.
How Long Do Fruit Tree Roots Grow?
The maximum length of a fruit tree’s roots is often 25 feet long, about the length of the tree’s drip line. On the other hand, dwarf fruit trees have roots about 15 feet long. As a general rule, it’s best to keep fruit trees at least 25 feet from structures such as fences, walls, and foundations to avoid damage.
Generally, the roots of fruit trees are responsible for gathering primary resources from the surrounding environment such as:
- Nutrients
- Water
- Oxygen
Many of these resources are located in the topsoil, which is why so many roots are shallow and grow horizontally.
A large number of surface roots also help anchor the tree in times of strong winds and when herbivores rub or lean against the tree. This is one reason why running livestock in orchards is beneficial.
However, if the soil is compacted (common in backyards and around construction sites), the tree will have a difficult time growing and pushing its roots through the soil. This can stress the tree and cause it to have reduced resources, leading to issues such as yellow and dropping leaves, blossoms, and fruit. Over enough time, the fruit tree can die.
The tree will continue to use its remaining resources growing and spreading to find suitable resources. If the roots run into any obstacles, they will grow around the object and continue in their original direction of growth.
Although it depends on the soil profile and availability of water, the root system of a mature fruit tree can reach a maximum length of up to three times the height of the tree. For a full-sized tree, this equals a length of 25 square feet or more, while dwarf fruit trees have root systems that are closer to 15 square feet.
Despite the far-reaching nature of a fruit tree’s root system, its growth is not considered invasive because it often depends on soil conditions. Invasive trees generally thrive in a variety of soil conditions and are difficult to get rid of.
However, if you’d like to be safe and limit your fruit tree’s horizontal root growth, there are a couple of things you can do:
- Install root barriers
- Keep the tree potted
Root barriers can be used to redirect the tree’s roots deeper into the soil and away from fences or foundations. This physical blocker protects your property as well as the fruit tree. On the other hand, planting the fruit tree in a pot will naturally bind the roots.
If you’d like to get an idea of a good root barrier you can use for your fruit trees, check out this root barrier on Amazon.
Keep in mind that many fruit trees grow an average of 36 inches per year, so they can quickly outgrow their root barrier or pot. Because of this, it’s best to provide potted fruit trees with a new, larger pot every 3-5 years. If you feel comfortable, you can also prune the roots during this time to slow the tree’s growth.
How Deep Do Fruit Tree Roots Grow?
Fruit trees typically have shallow roots, with 90% of the roots found in the first 2′ of soil. Other, deeper roots can be found in 12-16″, with some reaching up to 3′ deep. While many factors contribute to the depth of fruit tree roots, the main factors are the soil’s water, nutrients, and space.
Most roots are found close to the surface, with 90% or more of all roots located in the upper 60cm [24 inches].
Martin Dobson, Arboricultural Advisory and Information Service
Fruit tree roots grow to different depths depending on environmental conditions such as:
- Soil packing and quality
- Airflow
- Water content
- Bedrock
One of the deepest roots from fruit trees is the taproot, which is a vertical, singular root that extends straight down into the soil in search of water.
Although the majority of the tree’s root system spreads out horizontally to seek resources in shallow soil, some roots grow deep into the soil to provide more anchorage and feed on the deeper water and nutrients. This is especially beneficial if the fruit tree is growing in a dry region. Generally, these trees are more self-sufficient, especially in times of drought as their deeper roots can access deeper water tables.
Deep rooting can be encouraged by deep watering, which is watering long and deep amounts instead of shallow and light. This mimics long, heavy rains, which many fruit trees have evolved to favor (also helping to produce more abundant and juicier fruits).
If the fruit tree’s roots encounter unfavorable conditions, they’ll stop growing and turn horizontally or retreat back towards the surface. For example, roots will only grow a few feet in waterlogged, peaty soil due to the lack of proper aeration. On the other hand, if the soil is loose with good airflow, the deepest roots can reach over three feet.
Dwarf rootstocks feature an effective feeding root depth of 1-2’, while full-size trees probe 2-3’ deep.
The University of California, Santa Cruz, Center for Agroecology & Sustainable Food Systems
Can Fruit Tree Roots Damage Structures?
The roots of fruit trees are rarely the cause of foundation damage but can displace walls or fences as they grow. This is due to the shallow root systems that spread horizontally just under the surface. Fruit tree root systems are more likely to destabilize the ground than directly cause any damage.
While unlikely, fruit trees that are planted close enough can damage:
- Foundations
- Fences
- Walls
- Pipes
- Fire Hydrants
Although fruit tree roots are often blamed for interfering with foundations, they cannot actually harm bedrock through growth. Small tree roots can penetrate pre-existing cracks in the foundation but are not strong enough to cause any damage.
Generally, the roots of fruit trees will grow towards sources of oxygen and water, especially if they’re in environments that lack these resources overall.
If there is water under the foundation, roots can dry out shrinkable clay soils. This indirectly causes damage by contributing to the depletion of soil moisture which can cause the foundation to recede into the ground. However, this situation is uncommon and old age is a more likely culprit in foundation damage.
In the book The Hidden Life of Trees, Peter Wohlleben busts the myth that the tree’s roots are attracted to water from water pipes. He shows that the more likely case why they’re attracted to the pipes is that they generally have looser ground, which allows for more air and space for root growth. The water is more of a bonus.
If there isn’t enough space in your yard, a dwarf fruit tree is a good option that doesn’t require as much space as its full-sized counterpart.
Additionally, using a rootstock that’s less aggressive will help prevent any potential damage.
How Far Away Should You Plant Fruit Trees From Structures?
As a general rule, fruit trees should be planted at least 25 feet away from structures such as foundations and walls. This will avoid any potential damage from the tree’s roots or branches. It will also ensure that the plant has enough space to grow and find sufficient nutrients in the soil.
Along with keeping a minimum distance of 25 feet from structures, aim to keep your fruit trees within 50 feet of other flowering trees and plants.
This will boost the pollination effects from other fruiting trees and flowers such as companion plants. Any farther than 50 feet and the chance the pollinators will visit both a nearby flower and your fruit tree’s flowers is significantly reduced.
In the end, aim to plant your fruit trees at least 25 feet away from other plants and structures and you should be fine. If you’d like to be on the safe side, consider growing varieties that have less invasive rootstocks or dwarf varieties. You can also keep the tree potted or add a root barrier if you’d like!