How to Control Palm Wilt Naturally

  Malibu has one of the best environments for Palm Trees provided we properly take care of them. I have been in Malibu since 1984, and I have seen many beautiful Palm trees die and not from a natural death but from a totally unnatural death and one that was not necessary.

Not long ago, it was not uncommon to find Palms growing over 100 years old! It would be interesting to see if there are any palms in southern California that are even close to that even tho they were first brought here around 100 years ago. There is only one palm that is native to southern California - Washington filifera, the California fan palm.

The rest of the palms you see everywhere live here because we planted them and have somehow kept them alive. I say "somehow" because most folks haven't the faintest idea of how to properly take care of their palm trees.

It doesn't help that the  "experts" themselves do not seem to understand either. I see massive amounts of fertilizers applied to palms as if high nitrogen was the answer to everything. It is the primary cause of everything from pests to diseases.

I recently started a new customer who has a Date Palm about 25 years old that has Fusarium oxysporum  "Palm Wilt". A Very dangerous pathogen that will kill these Palm Trees within a short time. Usually, Arborists will recommend replacing the palm with a different variety. One that will not catch this disease since it is easily spread (usually by gardeners and tree folks that do not properly clean their tools!).

Here is my  "opinion" on what is happening here, and how to not only avoid it but how to properly deal with this problem. Contrary to popular belief, you can save a palm tree that has this disease and keep it alive and well for many years as well as prevent the healthy palms you have from getting it.

First off, the main problem with any disease is the soil. This disease is no different. 

We damage the soil by:

Destroying the soils natural microbiological balance thru applications of chemicals from fertilizers to weed killers to snail baits.

Destroying the land thru the constant use of chemicals in our water supply (water that is treated to kill bacteria! hint; soil needs bacteria).

Destroying the earth as well as damaging the trees root system thru over watering.

It is no wonder that diseases and pests flourish in this type of environment!

By the way, the first thing this person did to the sick palm was to dump high nitrogen fertilizer all over the place. High nitrogen is the perfect food for this pathogen!

This particular disease (actually all diseases) depend on one primary factor in the plant -low trace minerals/high nitrogen. These two always go together, and they provide a perfect environment for diseases and pests.

I wonder how many folks have ever tested the Brix level of their palms? If they did, they would be shocked to find that the Palm would have a very low Brix level. 10 unless it was taken care of properly, in which case it would be above 22.

So the key to keeping your palms healthy is to help them keep their Brix levels high by providing them with a healthy soil environment. To which rock dust, compost and mulch are provided along with an excellent organic fertilizer source (slow release, low nitrogen). A monthly organic foliar application would go a long way towards keeping your palms healthy.

Andy Lopez

Invisible Gardener

Any questions? Email me andy@invisiblegardener.com