Canary Island Palm brown fronds

[Alex_San Diego]

My Canary Island Palm is about 20 years old.  Has never done great, now getting worse. Many fronds brown, including new fronds on top. Brown starts on one side of the frond, then moves to other side of the frond. Asked at a nursery a few years ago, one person said it had a fungus and will die no matter what I do, another said needs more nutrients. I got some Vigoro palm food, which seemed to fix the problem for a couple of years (no more brown fronds), but still fertilizing and now brown is back.  What do I do? More or different fertilizer? Any specific nutrients I should add? More or less water? Could it be infested with ants, would that cause this problem? What is my best watering plan HELP!

I’m in San Diego, about 4 miles from beach. Tree in full sun. Soil is sandstone, poor quality.

[jerp33]

Sounds like fusarium wilt (death sentence). If you search it you will see photos showing symptoms. I have been told that the palms will fail within a couple of years. I have seen this one sided frond dying and removed it and 3 years later, no symptoms. I believe mine was drought related and not fusarium.

[Merlyn]

On 8/17/2021 at 12:35 PM, Alex_San Diego said:

My Canary Island Palm is about 20 years old.  Has never done great, now getting worse. Many fronds brown, including new fronds on top. Brown starts on one side of the frond, then moves to other side of the frond. Asked at a nursery a few years ago, one person said it had a fungus and will die no matter what I do, another said needs more nutrients.

Some photos would help diagnose the problem, but from what you are describing Fusarium is a possibility.  There are other rachis blights that *can* cause similar symptoms, and you can treat those with a systemic fungicide like Banrot.  Banrot is also claimed to treat Fusarium, but I don't know that it actually will do that.  Generally speaking if it is Fusarium, the palm will die regardless of what you try.  Here's a good read on it: https://edis.ifas.ufl.edu/publication/pp139

There are other deficiencies that can cause leaves to brown and die early, like Manganese and Magnesium, and supplementing your regular fertilizer can help cure those.  If you can post a couple of photos, people here can help figure out what is causing your problem.  It's not *guaranteed* to be Fusarium, though that apparently is common in Canary Dates out in CA.  Here's my "cheat sheet" on nutritional deficiencies:

• Nitrogen - Older fronds turn light green uniformly, new fronds remain dark green until deficiency is really severe
• Potassium - Older fronds get translucent yellow/orange or dead spots on leaves, especially at the tips. Sometimes tips are curled or frizzled. Always starts at tips of oldest leaves, moving inwards
• Magnesium - Yellow linear bands on leaves but generally transitions to solid green at the base of each leaf. Never causes leaf tip necrosis
• Iron - Many times caused by overly mucky soil and root rot. Starts with new spear leaves with yellow-green or even white, possibly with spots of green.
• Manganese - Lengthwise necrotic streaks in leaves with dead and curled leaf tips. Similar to bands showing Magnesium deficiency
• Boron - Bent or necrotic or distorted leaf tips, distorted or bent spear, bands of dead spots on new fans, spears that won't fully open
• Water - Underwatering brown at the edges first, later followed by yellowing of the whole leaf. Overwatering can be drooping fronds turning yellowish and losing color