Q. I have three mature
California fan palms, aged at least twenty years, planted quite close to each
other and located in Mesquite, Nevada. Two or three years ago, one showed signs
of early leaf browning and soon died. Now leaves of others are quite yellow but
stems and new growth at the top of the tree is green. I’m afraid they are going
the same way as the one that died! Disease?
California fan palms, aged at least twenty years, planted quite close to each
other and located in Mesquite, Nevada. Two or three years ago, one showed signs
of early leaf browning and soon died. Now leaves of others are quite yellow but
stems and new growth at the top of the tree is green. I’m afraid they are going
the same way as the one that died! Disease?
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| Yellowing palm leaves of the reader |
A. I do not think the
yellowing and scorching is directly related to disease. I think it is primarily
a soil or plant nutrient problem that will not be solved simply by adding
fertilizers. Irrigation might be part of the problem IF the trees are watered
too often. In your particular case, I think several things may be going on at
once.
yellowing and scorching is directly related to disease. I think it is primarily
a soil or plant nutrient problem that will not be solved simply by adding
fertilizers. Irrigation might be part of the problem IF the trees are watered
too often. In your particular case, I think several things may be going on at
once.
I’m
a big proponent of soil improvement when planting anything in our desert soils.
In Mojave Desert soils, and soils brought in as fill around homes in housing
developments, soil improvement at the time of planting is an absolute must even
if you are planting cactus.
a big proponent of soil improvement when planting anything in our desert soils.
In Mojave Desert soils, and soils brought in as fill around homes in housing
developments, soil improvement at the time of planting is an absolute must even
if you are planting cactus.
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| Desert soils are usually very low in organic matter like this soil. The light tan color of the soil is an indicator of a very low percent of organics in the soil. |
If
your soil is tan colored or very light brown, there is zero organic matter in
that soil. Palms are typically planted without much consideration for any kind
of soil improvement. They are planted in tiny holes, the roots surrounded with
very little if any improved soil. Once planted, the soil surrounding the plant
is covered with rock mulch.
your soil is tan colored or very light brown, there is zero organic matter in
that soil. Palms are typically planted without much consideration for any kind
of soil improvement. They are planted in tiny holes, the roots surrounded with
very little if any improved soil. Once planted, the soil surrounding the plant
is covered with rock mulch.
In
this type of soil environment roots suffocate and die over time. If they don’t
die in the first couple of years, they have a great deal of difficulty taking
up the proper nutrients from the soil even if fertilizers are applied. They
become unhealthy.
this type of soil environment roots suffocate and die over time. If they don’t
die in the first couple of years, they have a great deal of difficulty taking
up the proper nutrients from the soil even if fertilizers are applied. They
become unhealthy.
The
plants react to this poor soil environment by turning yellow. It’s not a
disease caused by disease organisms directly but the plant color indicates they
are in poor health.
plants react to this poor soil environment by turning yellow. It’s not a
disease caused by disease organisms directly but the plant color indicates they
are in poor health.
To
correct this problem, add organic material to the soil surrounding the roots
and improve water drainage and movement of air into the soil. Until this is
done, you will see very little improvement to these plants just by adding
fertilizer.
correct this problem, add organic material to the soil surrounding the roots
and improve water drainage and movement of air into the soil. Until this is
done, you will see very little improvement to these plants just by adding
fertilizer.
In
the past we used a technique called “vertical mulching”. It is no longer talked
about much anymore but it was effective. Vertical mulching created vertical
holes to a depth of 2 to 3 feet around the plant in the root area. These
vertical holes were filled with improved soil.
the past we used a technique called “vertical mulching”. It is no longer talked
about much anymore but it was effective. Vertical mulching created vertical
holes to a depth of 2 to 3 feet around the plant in the root area. These
vertical holes were filled with improved soil.
Vertical
holes were created using a high-pressure watering device or a post hole digger.
Pull back the rock mulch where you are going to create vertical holes a foot or
two from the trunk. Create the holes using a post hole digger or water from a
high-pressure nozzle to a depth of 2 to 3 feet. Be careful of irrigation lines.
holes were created using a high-pressure watering device or a post hole digger.
Pull back the rock mulch where you are going to create vertical holes a foot or
two from the trunk. Create the holes using a post hole digger or water from a
high-pressure nozzle to a depth of 2 to 3 feet. Be careful of irrigation lines.
Fill
these holes with a 50-50 mixture of the soil you took out of the hole mixed with
compost, minus any rocks larger than a golf ball. Create a minimum of four
holes around these trees. Use these spots in the future to add fertilizer once
a year. Apply more compost on the surface to further improve soil at the
surface and put back the rock mulch.
these holes with a 50-50 mixture of the soil you took out of the hole mixed with
compost, minus any rocks larger than a golf ball. Create a minimum of four
holes around these trees. Use these spots in the future to add fertilizer once
a year. Apply more compost on the surface to further improve soil at the
surface and put back the rock mulch.
Make
sure plastic is not on the soil surface surrounding the plants and under any
mulch. Plastic on the soil surface can create similar problems.
sure plastic is not on the soil surface surrounding the plants and under any
mulch. Plastic on the soil surface can create similar problems.