We have a palm tree in our backyard and we’re looking at getting another one, but we weren’t sure if it would cause problems such as damaging our patio or foundation. So, I did some research to find out more. Here’s what I found.
According to California Polytechnic University, palm trees are not invasive and have a low potential for root damage. Their roots are shallow and grow no larger than a few feet wide and deep. However, the roots can displace nearby structures such as sidewalks and foundations if planted too closely.
So, while palm trees don’t have invasive roots, where are they native to, just how long and deep do they grow, and how far should they be from structures? Let’s take a closer look.
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Where Are Palm Trees Native To?
|States||Native Palm Trees|
|Florida||Everglades, Needle, Cabbage, Thatch, Silver, Royal, Saw, Buccaneer, Dwarf, Miami, Scrub, Key Thatch|
|Georgia||Cabbage, Needle, Saw|
|California||California Fan Palm|
Palm trees are native to tropical and subtropical regions including the Caribbean, North America, South America, and some areas of the South Pacific and southern Asia. While they can grow in many climates, they prefer moist and hot regions, typically including wet, lowland forests.
You can trace palm trees’ origins back to areas of India, Northern Africa, Southeast Asia, and the South Pacific islands.
However, several species are native to the US.
Fourteen species of palms belonging to 9 genera, are native to the United States. Only one occurs in the West; the others are naturally distributed in the southeastern and southern States—from North Carolina through Florida and the Gulf Coast into Texas and as far inland as Arkansas and southeastern Oklahoma.
Palm Trees in the United States, Miriam L. Bomhard, Range Conservationist Forest Service, 1950
So, while there are 14 species native to the US, most of them are (unsurprisingly) found in Florida.
It’s important to keep in mind that while invasive plants get a bad rap, it doesn’t necessarily mean that they’re bad. For example, many invasive plants are opportunists and pioneers, taking advantage of poor soils and improving them. Also, what is considered “invasive”? Birds carrying seeds from other locations?
Now, let’s take a look at their root structure so we can plant them properly.
How Long Do Palm Tree Roots Grow?
Palm tree roots grow an average length of 3 feet in search of water and nutrients. Since palm trees aren’t technically a tree, but a grass, the majority of their roots grow horizontally to help stabilize the main plant in high winds (common in climates close to the ocean).
Supporting the main part of the “tree” are the wide and shallow roots and large plant cells, which contain high amounts of lignin. While woody trees are rigid and can snap under enough pressure, palm trees remain flexible and can bend in the wind.
Palms rely on overlapping leaf bases, thickened enlarged cells, and prop roots to stay up. This strategy is also used by cycads and tree ferns.University of California Museum of Paleontology
Overall, palm tree roots are fairly thin and wispy and cover a larger surface area in the soil compared to most other true, woody trees.
How Deep Do Palm Tree Roots Grow?
While the majority of the palm tree roots grow horizontally, the vertical roots grow 2-3 feet deep in search of deeper water and nutrients. Because their roots aren’t as strong as woody trees, such as fruit tree roots, palm trees prefer very loose, sandy, soil.
Palm tree roots grow at different depths depending on factors such as:
- Soil packing and quality
- Water content
Additionally, watering palm trees with shallow water promotes excessively shallow roots. This can pose a problem as the roots destabilize the tree, causing a larger chance of collapse. It also means the plant will be more affected by hot conditions and drought.
For best results, aim to soak the soil 2-3 feet deep when watering. This will help the tree establish water independence and cool itself effectively.
Do Palm Trees Have Damaging Roots?
According to the SelecTree tool by California Polytechnic University, palm trees have a low potential for root damage (source). So, while damage from their roots isn’t likely, it is possible if palm trees are planted too close.
For example, this palm tree is displacing the sidewalk near our house.
Since palm tree roots are smaller and more fibrous than woody trees, their roots won’t cause damage to structures. However, the mass of their roots can absorb water and displace structures such as sidewalks, driveways, and foundations.
How Close Can Palm Trees Be Planted to the House?
Ideally, plant palm trees at least 10 feet away from your house or other structures. For example, our palm tree is around 11 feet away from our house.
Planting at this distance will not only help avoid root damage but help avoid roof damage from fronds and the trunk if they break. Even though palm trees are not woody and are more closely related to grass, their trunks are still filled with water and are heavy if they fall.
This is because palm trees don’t have rings, but instead have trunks with large, tube-like cells. This is due to a lack of a vascular cambium (what makes the “wood” of trees). As a result, instead of growing wood with rings, they grow fibrous, spongey, and wet trunks. This also makes them extremely difficult to cut down and dry out.
These large, tubular cells in palm trees are what help transfer nutrients and water up through the tree as it grows. On the other hand, the vascular cambium from woody trees is much denser and takes longer to grow.
While palm trees aren’t invasive and their roots are unlikely to damage structures, they should still be planted at least 10 feet away from those structures to be safe.
The grassy nature of palm trees means their roots are weaker than woody trees, but they’re more densely packed in the soil, potentially having a greater chance of soil displacement.
There are many different types and species of palm, so make sure you confirm which one you have before planting it near your house or other structures!