PREVENT AND TREAT DISEASES FOR YOUR ARIZONA PALM

Palm Trees are always great for turning your outdoor space into a tropical paradise or create that luxurious feel on your commercial property. They even come in many different shapes, sizes, and variations to match your dream landscape. Some may not know that aside from the California Fan Palm, Palm Trees, although spread throughout the state, are not native to Arizona.

However, did you know that palm trees aren’t even real trees? Because palm trees don’t form rings as they age, they are classified as Arecaceae. They are, botanically speaking, more closely related to grass than for example, a pine tree. Keeping that in mind, it’s important to understand the potential diseases that can affect your palm and the steps you can take to help prevent them from getting sick and keep your outdoor paradise looking great year-round!

So what popular non-native Palm Species can be found in the Greater Phoenix Area?

• Canary Island Date Palm (Phoenix Canariensis)
• Mexican Fan Palm (Washingtonia Robusta)
• Pygmy Date Palm (Phoenix Roebelinii)
• Queen Palm (Syagrus Romanzoffianum)
• Date Palm (Phoenix Dactylifera)

We’ve put together a description of a couple of diseases that could be affecting the health of your beautiful palm as well as tips to keep your “tree” as healthy as possible in Arizona’s climate.

LEAF SPOTTING: Are your palm’s fronds suffering from circular, brown, oily, or mold-like spotting? This may be a sign that your palm tree has a Leaf Spot Fungi Disease. These diseases are common and may occur with different fungi species. It’s important to take a look at your palms surrounding conditions and current care as well as taking preventative and corrective measures prior to treating. Fungi thrive in humidity. While that may not be the largest concern in Arizona’s relatively dry climate, here are a couple of steps to keep in mind when preventing fungus from invading your tree.

• Water your palms at the base and not directly on the fronds or leaves. Watering directly on the leaves increases humidity around the plant and puts them at risk of fungal infection.
• Consider surrounding air circulation. You may need to clear some plants around your palm if it seems too crowded to allow the natural breeze to blow around your palm tree and provide the proper circulation that it needs.

Typically treatment for Leaf Spotting is to prune the tree of the infected fronds as well as applying fungicides to prevent further spread of infection. It is important to pay attention to your palm’s nutritional needs first to make sure that your tree does not get sick further after pruning.

Your tree may have been experiencing a nutritional deficiency that allowed it to catch the fungal infection in the first place. It may be helpful to consider a new fertilizer to help aid the process. If you are unsure if your tree is sick or is showing symptoms, it is important to always call a professional and have them take a look and provide insight on the best treatment possible for your Palm Tree to recover and thrive.

Fusarium Wilt: Also a fungal disease, Fusarium wilt can affect a variety of plants including the Queen and Mexican Fan Palm. For many years this disease had only been spotted in Florida and Texas. The first sighting of Fusarium Wilt in Arizona was in 2016 and had been spotted over the last several years. If your palm is suffering from this disease, you may notice the following symptoms. Typically the palm will start showing signs from the bottom of the fronds and gradually making its way up the tree.

• Vascular browning
• Wilting
• Leaf Drop (Prematurely)
• Stunting
• Yellowing or Lightening of fronds (chlorosis)
• Death of your Palm

What makes Fusarium Wilt unique is how rapidly it can kill your palm’s canopy. It’s important to be aware of the signs especially since this disease appears to be relatively new to the Arizona region as an airborne fungal pathogen. Because this disease is airborne, it can be difficult to prevent this disease from occurring and it’s important to note that there is no cure once your palm is infected. However, there are steps you can take to help extend the life of your palm.

• Treat your tree with fungicides that contain thiophanate-methyl: This will help prevent further fungal infections in the future and may help extend the life of your palm.
• Fertilize your tree: Your palm may require additional nutrients it may not otherwise be getting. This will be important in your palm’s overall health and also prevent further infection. Proper watering is just as important!

It’s important to look at other factors when considering the health of your palm tree in its not-so-native environment of Arizona. Because they are imported into the state to give off that tropical look, the truth is, we’re in the desert. And that can come with some complications. In October of 2020, it was reported that Arizona’s monsoon season was the driest ever recorded as well as being one of the hottest summers recorded.

Because of the lack of moisture in the air due to the anticipated monsoon rain, many locals had noticed their palms dying in the heatwave regardless of using a specialized fertilizer for palms or watering them on their own. Does this mean we have to give up our tropical landscape? Absolutely not. However, it can be important to educate ourselves on the different palm species and those that adapt better than others and understand the proper upkeep when caring for your palm tree.

The Queen Palm, although incredibly popular in landscaping found in the Greater Phoenix Area, really isn’t built to withstand extreme weather patterns such as the intense dry heat that the Sonoran Desert is known for. The appeal of the Queen Palm has been known for adding the lush and tropical vibe to either a pool area or courtyard for a hotel or business complex.

When exposed to the weather here such as intense heat, (or near-freezing temperatures in winter), wind, and the dry climate, these factors can put this palm at higher risk of getting a palm disease resulting in the fronds browning, dying, and in need additional care and removal of the dead leaves and possibly the tree itself.

So which Palm Species are best adapted for Arizona’s climate?

The California Fan Palm: As we mentioned before, the California Fan Palm is the one Palm Species that can be naturally found in Arizona. That means they are more likely to adapt to the state’s weather changes better than an imported species.

Date Palms: Date palms also add that dose of paradise to your landscaping and can be a great addition with a reduced risk of conflict with the local climate. The best part, date palms love the dry, warm, and sunny weather!

Canary Island Date Palms: Also known as the Pineapple Palm or Phoenix Canariensis, is another palm variety that can thrive in Arizona. Again adding to the aesthetic of paradise and can grow up to be a beautiful tree up to 60 feet tall.

Understanding the different species of palm trees for your landscape and how to properly care for them in Arizona can be quite a challenge. Even more so when you begin to see signs of disease and don’t know whether a fungicide will do the trick, if you need frond removal or if it’s best to remove the entire tree altogether. That’s why we’re here! At Jose Knows Trees, we are the professionals so you don’t have to be. Our job is to know how to keep your yard and landscape looking their best.

If you begin to see signs that your palm may be in need of additional care or unsure if removal may be necessary, please give us a call. We have many years of experience and great reviews and can’t wait to help you get your trees in the best shape of their lives.