Desert Fern Tree Arizona

What is a desert fern?

What is its scientific name?

What makes Arizona such a good location for growing a desert fern tree?

The desert fern tree is known by the scientific name Lysiloma watsonii. This tree is an ideal option for growing in Arizona and other desert climates because it enjoys full sunlight, warm temperatures, and well-draining soil conditions. It also likes slightly alkaline soil.

Since the tree is partial to the conditions that are most commonly found in the desert, it is a great option for use in xeriscaping. If you’re looking for a tree you can utilize and incorporate into your desert landscape, look no further! When it comes to the desert fern tree Arizona is a great place to grow this plant.

Read through the article below to learn more about the desert fern tree and get an idea of what to expect if you choose to grow it in your lawn or garden.

Desert Fern Trees in Arizona

1. How much water and humidity does this tree need?

  • The tree needs a little bit more water than some drought-resistant tree options for Arizona, but it can still handle fairly dry conditions. If it is very hot outside, it’s best to try watering this plant at least once a month. Give it a deep watering that reaches its roots for best results.
  • The tree also likes very dry air conditions. It needs low humidity to allow it to grow and flourish. Too much humidity in the air regularly can prevent it from growing into a healthy, mature tree, so it works well in desert climates for this reason.

2. Can the tree handle harsh sun and cold weather both?

  • The tree does well when grown in bright sunlight, and it can tolerate harsh sun when fully grown. It can also tolerate high temperatures if it is grown in a location with slight, filtered shade.
  • The tree can also handle some cold temperatures, but it is only cold hardy down to 25 degrees Fahrenheit. If the tree gets any colder than this, it may risk frost damage and could die, especially if the cold temperatures are sustained for more than one night.

3. What are the best and worst areas to plant this tree?

  • Ideally, this tree should be planted in a location that gets a lot of bright, full sunlight and even some reflected heat throughout the day. It can be placed in a location with very slight filtered shade, especially in places that get higher temperatures.
  • The tree should never be placed in a location where it receives any runoff or pooling from gutters or other fixtures in your home or yard.
  • It should be far enough away from buildings and structures that it has room to grow, as well, and should have space for its roots as well as for its canopy.

4. What kind of soil should you use, and does it need fertilizer?

  • This tree should be grown in well-draining soil. It likes slightly alkaline soil and can grow best in poor quality substrate, which means it does well in the sandy and rocky conditions of the dry desert.

5. Can this tree be grown in a container or indoors?

  • Theoretically, the tree could be grown in a container or indoors, but it probably wouldn’t be very happy. It also likely would never flower, because it would not be kept under its ideal growing conditions.
  • It’s better to give this tree enough room to spread out and grow. It also prefers to be in such bright sunlight and high temperatures that it is best kept outdoors.

6. How big does this tree get when mature?

  • When grown in a lawn or garden, this tree usually reaches ab out 15 feet in height as well as about 15 feet in width, although it may go up to 20 feet tall and wide if given the perfect growing conditions.
  • When grown in the wild, this tree can reach over double that size, ranging up to 50 feet in height. This is because the wild desert climate conditions are ideal for the tree and it is given enough room to grow as wide and as tall as it wants to.

7. Does the tree flower, and if so, when?

  • Yes. The tree grows small white flowers that look like dandelions or powder puffs. These occur in the later part of the springtime or even the very early summer, depending on the climate where you live.

8. What kinds of insects does the tree attract?

  • The tree attracts some pollinators while it is in bloom. Bees, wasps, and hummingbirds all enjoy spending time pollinating its white puffy flowers. If you are looking for a tree that can contribute positively to your pollinator garden while still fitting into a xeriscape, the desert fern is a great solution that checks both of these boxes.

9. Is this tree prone to diseases and if so, are they preventable?

  • This tree is not prone to diseases or pests at all. It is extremely resistant to both and, as such, it is a great beginner tree since it requires very little care or concern after it has become fully established.

10. What are some pros of growing this tree in Arizona?

  • The tree loves the climate and conditions found throughout most of Arizona, and it is sure to grow and thrive as long as it is placed in full sunlight and well-draining soil on your property.
  • The tree can grow tall enough to provide some shade for your home.
  • The tree can also provide some wind protection, especially when paired with multiple of the same type of tree or with other tree options as well.

11. What are some cons?

  • The tree may not ever flower if you keep it in a shady spot. Although it is likely to grow its leaves with no trouble, you will never see its puffy white flowers, and will never attract pollinators for this reason.
  • The tree cannot handle the cold temperatures in some parts of the desert. Think about how cold it gets in your location, even at night in the winter, to help decide whether or not this tree is right for you.


If you’re looking for some ideas of how to use your desert fern tree in your landscaping, or if you just want to know what these trees look like when mature, we’ve got you covered. Check out the images below to give you some inspiration.

1. Growing Lysiloma Watsonii

This image shows a bright yellow-green tree and gives you some idea of what its fronds should look like. You can see what a healthy adult desert fern tree looks like in this picture.

2. California Native Garden

This picture shows a full canopy of several desert fern trees that seem to be growing close to one another. The trees are slightly more subdued green than those in the previous image.

3. Feather Bush

This picture shows a tree that has been trained into a specific shape. It has very yellow fronds and small flowers throughout its canopy of growth.