Palm Tree Guide — Cathedral City City Council, September 10, 2025

GDY

CONSULTING
1/2/2020

CITY OF INDIAN WELLS

PALM TREE GUIDE

Prepared By:

Gregston D. Young
GDY Consulting
Cell-760.250.1229
[email protected]
IA Certified CAIS, CIC, CID, CIT, CLIA, CLIA, CLWM-86964 ISA Board Certified MASTER Arborist WE-9732B
ISA Tree Risk Assessment Qualified
NCCCO Certified 130387931
QAL 131706 ABD
Member ASCA

©2020 GDY Consulting. All Rights Reserved. No part of this publication may be reproduced or distributed in any form or by any means, or stored in a database or retrieval system, without prior written permission of GDY Consulting.

CITY of INDIAN WELLS PALM TREE GUIDE

Contents
What is a Palm Tree? ......................................... 2 3,000 Palm Species ........................................ 2 Coachella Valley Native .................................. 2 Parts of the Palm ................................................ 2 Leaves............................................................. 2 Trunk .............................................................. 2 Flowers, fruits and seeds ............................... 3 Roots .............................................................. 3 Common palms used in the Coachella Valley. ... 4
Phoenix Dactylifera- (Date Palm) ................... 4
Female date palms ..................................... 4 Male (Macho) ............................................. 5 Washingtonia palms....................................... 6 Washingtonia filiferia-California fan palm . 6
Washingtonia robusta-Mexican fan palm .. 6
Washingtonia hybrid fan palm ................... 7
Specialty palm species that are well suited for
Coachella valley .............................................. 7 Bismarckia nobilis (Bismarck palm) ............ 7
Brahea armata (Mexican blue palm) ......... 7
Mexican blue palm ..................................... 7 Butia capitata (Pindo palm) ....................... 8
Paurotis Palm (swamp palm) ..................... 8
Phoenix roebelinii (Pygmy date palm) ....... 8
Sabal palmetto (Cabbage palm) ................. 8

Palms NOT Suitable for Coachella Valley ........... 9
Syagrus romanzoffianum (Queen palms) .. 9
Trachycarpus fortunei (Windmill palms) ... 9
Recommended practices for vitality of palms ... 9
Trimming ........................................................ 9 Washington robusta palms ........................ 9
Washington filiferia palms ....................... 10
Phoenix dactylifera palms ........................ 10
Fertilization of palms ................................... 11 Palm watering recommendations ............... 11
Irrigation .................................................. 11 Example water schedule .......................... 11
Key signs of potential palm tree failure ........... 12 Palm tree replacement recommendations ..... 14
Time of year to plant ............................... 14 Soil ........................................................... 14 Water ....................................................... 14 Planting depth ......................................... 14 Conclusion ....................................................... 15 Glossary ........................................................... 16 Glossary Continued .......................................... 17 Bibliography ................................................. 18

CITY of INDIAN WELLS PALM TREE GUIDE

What is a Palm Tree?

3,000 Palm Species
There are more than 3,000 species of palms
around the world. Palms are in the Arecaceae
family of perennial plants. They are monocots
and have more in common biologically with
grasses than with hard wood trees.

Coachella Valley Native
California fan palms, (Washingtonia filiferia)
named after our 1st president, are the only
native palms to the Coachella Valley. It is
believed that the Cahuilla Indians (the first
inhabitants of Indian Wells) where the first to
plant and transplant palms in the Coachella
Valley. The palms were important to the
Cahuilla because they could use the dead fronds
to thatch their houses, harvest and grind fruits
into flour, and modify the spine-covered frond
stems into weapons.

Parts of the Palm
Leaves
Fronds are the leaves of the palm. Palms have
the largest leaves of any trees. Photosynthesis
takes place in the fronds, which dominate the
palm crown. There are two classes of palm
fronds:
1) The Pinnate or feather leaf is long and
slender. Examples of this type are the Date
palm (Phoenix dactylifera), and the Pindo palm
(Butia capitata).

2) The other is Palmate or fan leaves, which are
circle shaped and makes near a 360-degree
circle. Examples include California fan palm
(Washingtonia Robusta) and Mexican blue palm
(Brahea armata).

Trunk
Palm stem or trunk, is the structure that holds
the leafy vegetation above the ground. Palm
stems have a single growing point or apical

Indian Wells Cahuilla Indians
Traditional Home with Palm fronds

CITY of INDIAN WELLS PALM TREE GUIDE

meristem. Most palms lack the capacity to
generate a new apical meristem, so if damaged,
the whole palm will die. The stem provides
transportation and storage of water, minerals,
and carbohydrates. Enabling palms to reach
heights of 100 feet or more. One or a few
irregular trunk constrictions usually represent
periods of abnormal reduced growth or stress,
from environmental events, such as severe cold,
disease, and culture or transplant shock.

Flowers, fruits and seeds
Palm trees make flowers and produce seeds.

There are both male and female flowers. Palm
species where each individual plant is either
male or female is called a dioecious species.

Example is the date palm, which has to be hand
pollinated in order to produce a commercial
crop of

dates. Palms with flowers of both sexes on the
same tree, are called monoecious, example is
Washingtonia robusta. Palm fruits vary in sizes
and shapes, typically fleshy, pulpy, mealy, or
fibrous, and contain one or more hard seeds.

There is a potential to stain concrete, so
removal of the inflorescences prior to fruit
drop, is recommended. While most palm fruit is
edible, precautions should be taken, many
other landscape plants fruit is poisonous.

Roots
Palm roots tend to be diffuse and small in
caliper. There is typically no massive tap root
below the tree. They fan out with small to
medium sized roots and have hair-like smaller
roots that occupy the soil. They do not thicken
like roots of hard wood trees. Root initials are
produced throughout the life span of the plant.

Making even very large specimens, able to be
successfully transplanted. Palm roots are
nowhere as invasive as hard wood trees.

Fan palm parts
Date palm parts
CITY of INDIAN WELLS PALM TREE GUIDE

Common palms used in the
Coachella Valley.

Phoenix Dactylifera- (Date Palm)
Female date palms
 Date palms make a great landscape
palm, as it is sourced locally from the
many date palm groves in the eastern
Coachella Valley. They are reasonable
priced for their size compared to other
trees. Date palms can successfully be
transplanted with proper equipment
and training.
 Grown in many tropical and subtropical
regions worldwide for its fruit.
 Fruit, is sweet and edible, but can stain
cement if not removed before fruit
drop
 Leaves, pinnate, spreading to slightly
drooping, to 12 feet long, leaf base to 1
foot wide, has 2 inch thorns along
petiole, can be dethorned when
trimmed.
 Height and growth, can reach 80 feet,
grows about 1 foot per year, but starts
to slow down to about ½ foot a year
when reaches about 40 foot.
 Trunks, 14” to 16” diameter, if diamond
cut, makes a nice manicured look, aerial
roots up to 5 foot is natural in taller
date palms, but can be manicured
nicely.

Common varieties used in landscape

Deglet Noor
Hard date, fruit used mostly for commercial
use, most common date palm used in
landscape.

Medjool
Fruit soft and sweet to eat, has a little shorter
and darker green fronds, making it more
attractive for landscape use.

Deglet Noor dates-Diamond cut trunk
Medjool dates
Diamond cut trunk
CITY of INDIAN WELLS PALM TREE GUIDE

Other Female Varieties

Zahidi
Transplants well, much shorter supply, tends to
produce multiple apical meristems on the sides
of the trunk, requiring annual removal.

Abbada, Barhi, Halawi, Honey, Khadrawi &
Thoory
Soft fruit and good eating, do not transplant
well, limited supply for landscape use.

Male (Macho)
 Macho dates are a great alternative to
Canary Island date palm (Phoenix
canariensis), transplants much better,
not susceptible to Fusarium wilt.

Machos can be trimmed to match
Canary Island date palms.
 Grown by farmers for the pollen,
usually one row on end of field of
female date palms.
 Fruit, pollen drops below palm and is
dusty, but does not stain cement.
 Leaves, pinnate, spreading to slightly
drooping, to 14 feet long, leaf base to
14 inches wide, has two inch thorns
along petiole, can be dethorned when
trimmed.
 Height and growth, can reach 60 feet,
grows about 1/2 foot per year, but
starts to slow down to about ¼ foot a
year when reaches about 40 foot.
 Trunks, 16 inch to 24 inch diameter, can
be diamond cut or flat cut to resemble
Canary Island Date Palms, very common
to have two foot to five foot of aerial
roots, but can be manicured nicely
 Heads, can be pineapple cut to
resemble Canary Island Date Palms

Macho dates- flat cut trunks,
Similar look to Canary Island date palms.

Macho dates- natural, before harvested or cleaned

CITY of INDIAN WELLS PALM TREE GUIDE

Washingtonia palms
Washingtonia filiferia-California fan palm
 Native to California desert areas
 Fruit, edible, was used by the native
Indians
 Leaves, palmate, to eight feet long,
blade (fan part) 4 X 5 feet, one inch
spines along petiole
 Height and growth, can reach 60 feet,
grows about one foot per year
 Trunks, 14 inches to 24 inches after
bark is peeled, can be left with dead
fronds hanging down, called a skirt,
dead fronds can be trimmed, leaving a
natural look, or bark can be peeled to
give a clean, manicured look.
 Makes a great landscape tree, easy to
move with proper equipment and
training. Transplants well, drought
tolerant after established, but will
require irrigation water in the desert
areas.

Washingtonia robusta-Mexican fan palm
 Native to Mexico
 Fruit, edible
 Leaves, palmate, to five feet long, blade
(fan part) 3 X 3 feet, one inch spines
along petiole
 Height and growth, can reach 90 feet,
grows two to four feet a year
 Trunks, 9 inches to 12 inches after bark
is peeled, can be left with dead fronds
hanging down or called a skirt, dead
fronds can be trimmed, leaving a
natural look, or bark can be peeled off
to give a clean manicured look.
 Makes a great landscape tree, easy to
move with proper equipment and
training, transplants well, the most
economical landscape palm.

Washingtonia filiferia- peeled
Washingtonia robusta- peeled

CITY of INDIAN WELLS PALM TREE GUIDE

Washingtonia hybrid fan palm
 The hybrid is a cross between the
W.filiferia and the W. robusta, has
characteristics of both. Sometime
referred to as filibusta (Unofficial
Scientific name).
 Fruit, edible
 Leaves, palmate, to seven feet long,
blade (fan part) 3 X 4 feet, one inch
spines along petiole
 Height and growth, can reach 70 feet,
grows about one foot per year
 Trunks, 11 inches to 14 inches after
bark is peeled, can be left with dead
fronds hanging down, called a skirt,
dead fronds can be trimmed, leaving a
natural look, or bark can be peeled to
give a clean manicured look.
 Makes a great landscape tree, easy to
move with proper equipment and
training. Transplants well, drought
tolerant after established, but will
require irrigation water in the desert
areas.

Specialty palm species that are well
suited for Coachella valley
Bismarckia nobilis (Bismarck palm)
Beautiful whitish green large palmate fronds,
does not transplant well.

Brahea armata (Mexican blue palm)
Dark green palmate palm, drought tolerant
after establishment

Washingtonia hybrid fan palms-non peeled
Bismarck palm
Mexican blue palm
CITY of INDIAN WELLS PALM TREE GUIDE

Butia capitata (Pindo palm)
Beautiful pinnate palm, slow growing

Paurotis Palm (swamp palm)
Slender multi palmate palm, works great as
center tree.

Phoenix roebelinii (Pygmy date palm)
Beautiful small pinnate palm, must source
locally. There are California department of
Agriculture restrictions from importing from out
of Coachella Valley.

Sabal palmetto (Cabbage palm)
Stocky palmate palm with long fronds

Pindo palm
Swamp palm
Pygmy date palm
Cabbage palm
CITY of INDIAN WELLS PALM TREE GUIDE

Palms NOT Suitable for Coachella
Valley
Syagrus romanzoffianum (Queen palms)
They survive when less than five feet, then as
they get taller the extreme hot dry days burns
the meristem down in the crown, so you don’t
see the damage until late fall or winter.

Trachycarpus fortunei (Windmill palms)
Not recommend as Coachella Valley Summers
are too hot.

Recommended practices for
vitality of palms
Trimming
 The larger the canopy of green healthy
fronds the better.
 Green palm fronds through
photosynthesis, produce sugars for the
palm to grow and keep healthy.

 Dead or dying fronds create extra
weight and wind drag on the palm; also
can be a fire hazard and a home for
rodents.
 Tree spikes should never be used on
any palms, damages the trunks both
visually and physically, spike holes serve
as entry for diseases and pests. The
palm has no way to heal the damage.
 Trimming tools should be sanitized by
soaking for 30 minutes in solution of
10% bleach and water between palms.

Washington robusta palms
 Should be trimmed once a year early
summer after inflorescences
(flower/seed stalk) are fully emerged.
 Trim all dead or dying fronds close to
the base, trim green fronds no more
than 10:30 to 1:30, as compared to a
clock face.
 Old frond bases can be peeled, as
wanted, for aesthetic looks, but never
closer than four foot from the crown.

Washingtonia robusta
proper “10:30 to 1:30” trimming
Washingtonia filiferia
Over trimming will damage the palms
CITY of INDIAN WELLS PALM TREE GUIDE

Washington filiferia palms
 Should be trimmed once a year early
summer after inflorescences are fully
emerged.
 Trim all dead or dying fronds close to
the base, trim green fronds no more
than 10 to 2, as compared to a clock
face.
 Old frond bases can be peeled, as
wanted for aesthetic looks, but never
closer than five foot from the crown.

Phoenix dactylifera palms
 Should be trimmed once a year early
summer after inflorescences are fully
emerged.
 Trim all dead or dying fronds close to
the base, trim green fronds no more
than 9 to 3 as compared to a clock face.
 Trunk should be removed of old Frond
bases or extended crown every five
years, leave crown or pineapple about
four feet long. This is to reduce weight
in the head and expose any pencil
necking or damaged trunks.

Date palm needs dead fronds and fruit removed,
trunk cleaned, crown raised. This will reduce
weight in top of palm (lower danger of breaking
the wind), lower danger of falling tree parts;
expose any “pencil necking” in the trunk.

Date palm with “9 to 3” trimming

CITY of INDIAN WELLS PALM TREE GUIDE

Fertilization of palms
 A good quality “Palm Special“ fertilizer
is recommended
• First application 60 days after
initial transplanting,
• One application in April
• One application in July
 Follow manufacturer recommended
quantities.

I recommend “Lesco 13-3-13 Palm and Tropical
Ornamental Fertilizer” sold by “SiteOne” or
“Lutz” “Maintaining Healthy Palms” Palm Tree
Spikes, (Palm spikes only have to be installed
once per year), found direct from Lutz, Amazon,
and Home Depot.

Palm watering recommendations

Irrigation
 Should be above ground, either a drip
hose with drippers, riser with a dripper
or bubbler on top. A minimum of three
per palm is recommended, five is
better. The water transports oxygen
down to the roots, water also pushes
the salts in the ground down away from
the roots.
 Deep water pipes are bad for the palms
and never recommended, they do not
transport oxygen down, and they push
salts up into the roots of the palms.
 A small basin is recommended to keep
water from running off before it has a
chance to soak in.
 Multiple water cycles are
recommended throughout the day with
short run times.

Example water schedule

Weekly days “ON/OFF”
Stagnant or standing water can be an issue for
palms. A short period of no irrigation is
recommended for both observation and
optimal root growth. If standing water is
observed after the “OFF” period, water
schedule should be reduced; alternatively if soil
is dry after last “ON” period, irrigation should
be increased.

Summer
Six days “ON”, One day “OFF” per week.

Winter
Four days “ON”, Three days “OFF” (not
consecutive) per week

CITY of INDIAN WELLS PALM TREE GUIDE

Recommended gallons per week
Hours/Minutes of time per station varies
depending on the size and quantity of drippers
per palm, so we will use gallons per week.

Divide the gallons of water per week by the
watering “ON” days each week, to get the
gallons of water per day on.

Washingtonia palms
New palms (first two years)
 Summer 225 gallons per week
 Winter 100 gallons per week

Established palms (more than two years)
 Summer 150 gallons per week
 Winter 75 gallons per week.

Phoenix dactylifera
New date palms (first three years)
 Summer 350 gallons per week
 Winter 200 gallons per week
Established date palms (more than three
years)
 Summer 225 gallons per week
 Winter 150 gallons per week
Key signs of potential palm tree
failure
 Decline in growth, vigor and/or loss of
green color in fronds.

 Crown or head tilting

Queen palm – Meristem fried
from Coachella Valley extreme
summer heat
W. robusta – damaged tilted head
CITY of INDIAN WELLS PALM TREE GUIDE

 Trunk tilting, cracks developing or
shrinking

 Center fronds falling out or fronds dying
back excessively

 Holes in sides of trunks about the size
of nickel or bigger.

 Pencil neck in trunk more than 50% of
girth reduction

W. filiferia- shrinking trunk, due to lack
of water uptake
Date palm- extreme frond die
back
W. filiferia- deteriorating trunk and
Palm Borer exit holes
Date palm-pencil neck
CITY of INDIAN WELLS PALM TREE GUIDE

 Deteriorating trunk or roots, also
excessive ant activity going up the trunk

 NOTE: If any of these key signs appear
on your palm, call an ISA (International
Society of Arboriculture) certified
arborist who specializes in palms. See
directories on ISA-arbor.com website.

Palm tree replacement
recommendations
Time of year to plant
The optimal time of year to plant a new or
replacement palm is February to middle of June
and September to middle of November; it is
best not to plant in the hottest or coldest
months.

Soil
If the soil has large amounts of clay or does not
drain well, dig the hole 25% larger and deeper,
install a four inch “L” shaped drain pipe with
drain sock, under palm to surface with
perforations only under palm (this is for
aeration and observation only, not for irrigation
or drainage), then back fill palm with washed
concrete sand.

Water
Water jet in with a ¾”PVC pipe on the garden
hose, as backfilling palm, be sure to remove all
air pockets.

Planting depth
Plant the palm root ball at the same level it was
before it was removed from the nursery or
field, covering air roots is ok, but not necessary.

W. Filiferia- deteriorating trunk
CITY of INDIAN WELLS PALM TREE GUIDE

Conclusion
This palm tree report is for general information
only. It is not meant to take the palce of
professional assistance from a trained ISA
Certified Arborist or Certified Master Arborist,
with certification in tree risk assessment and
palm trees. Call the expert; See ISA-arbor.com
website for list of local qualified Arborist.

GDY Consulting provides risk assessment
services and tree care recommendations.

Gregston D. Young is an ISA Board Certified
MASTER Arborist.

CITY of INDIAN WELLS PALM TREE GUIDE

Glossary
 Apical meristem-- is the growth region
in plants found within the root tips and
the tips of the new shoots and leaves.

In palm trees, the growing point, which
is also referred to as the bud or heart.
 Arecaceae-- are a botanical family of
perennial plants. Their growth form can
be climbers, shrubs, tree-like and
stemless plants, all commonly known
as palms
 Arborist-- Professional who possesses
the technical competence gained
through experience and related training
to provide for or supervise the
management of trees and other woody
plants in residential, commercial, and
public landscapes.
 Commercial use-- is any reproduction
or purpose that is marketed, promoted,
or sold and incorporates a financial
transaction.
 Culture shock-- from improper
transplanting or maintenance, and
recovery is hindered.
 Diamond cut or Classic cut—when the
trunk of a date palm has the petioles
cut to a diamond-shaped pattern.
 Dioecious species-- These plants
produce a male plant and a female
plant and not usually a single plant with
both male and female parts.
 Drip Line—Imaginary line defined by
the branch spread of the tree.
 Flat cut—when the trunk of a macho
date palm or a Canary Island palm tree
is cut smooth.
 Fronds-- The foliage of a palm tree or
leaf, where photosynthesis takes place.

 Fusarium wilt-- Unlike most fungal
diseases of palms, this disease is very
host specific, with the primary host
being Phoenix canariensis (Canary
Island date palm).
 Hard wood trees-- The most common
species in North America are oaks,
maple, hickory, birch, beech and cherry.
 Inflorescences-- The complete flower
head of a plant including stems, stalks,
bracts, and flowers
 Monocots-- are flowering plants, the
seeds of which typically contain only
one embryonic leaf, or cotyledon.
 Monoecious-- That has male and
female reproductive organs on the
same individual plant (rather than on
separate plants), either in different
flowers or in the same flower.
 Mulch—Material that is spread on the
soil surface to reduce weed growth,
retain soil moisture, moderate
temperature extremes, prevent damage
from lawn-maintenance equipment,
and improve aesthetic appearance of
the landscape.
 Palmate-- A compound leaf with more
than three leaflets (trifoliate) radiating
from the same point, resembling a hand
with the fingers spread.
 Palm crown-- An elongated
circumferential leaf base formation
present on some species of palms.
 Palm stem-- is the tree trunks of palm
trees.
 Photosynthesis-- the process by which
green plants and some other organisms
use sunlight to synthesize foods from
carbon dioxide and water.

CITY of INDIAN WELLS PALM TREE GUIDE

Glossary Continued
 Pencil necking—in palm trees, when
the trunks develop an area where it
slender down to a smaller
circumference, caused by lack of water,
nutrients or over pruning.
 Perennial-- is a plant that lives more
than two years
 Pineapple cut—usually on a macho or
Canary Island palm, trim the crown to
resemble a pineapple shape.
 Pinnate-- leaves, which are sometimes
described as being feather-like, have
leaflets entirely separated from each
other that are attached perpendicularly
to the rachis.
 Resistograph-- An instrument that
detects decay and cavities in trees and
timber.
 Root initials—the starting point of a
root.
 Root Zone—Area within the soil profile
where roots exist; typically the root
zone of trees extends beyond the drip
line.
 Skirt--Washingtonia palm, when the
dead fronds are allowed to cover most
or the entire trunk.
 Sounding-- Strike the tree sharply with
the hammer side of a hatchet or a
mallet.
 Tap root-- is somewhat straight and
very thick, is tapering in shape, and
grows directly downward
 Tomography—Tool used to measure
the decay inside trees.
 Transplant shock-- from improper
transplanting or maintenance, and
recovery is hindered.

 Tree Risk Evaluation—Assessing the
chances of a tree causing damage to
people or property
 Trunk constrictions-- appear as a
narrow area on the trunk and are
caused by a disruption of the palm's
diameter for that year. Some of the
causes are nutritional deficiencies,
drought, hard freezes and over-pruning.

Also called pencil necking.
 Washed Concrete Sand-- Comprised of
a washed and screened coarse sand

CITY of INDIAN WELLS PALM TREE GUIDE

Bibliography
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D.E., P.E. Drip and Micro Irrigation Design and
Management; Irrigation Training and Research
Center; 3rd Edition; 2007
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PALMS; Betrock’s Information Systems, Inc.;
2007
Donald R. Hodel. The Biology and Management
of Landscape Palms: Western Chapter
International Society of Arboriculture; 2012
Gary W. Watson and E.B.Himelick. Planting
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Arboriculture: 1997
James C. McCurrach. PALMS of the World;
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Julian A. Dunster. Tree Risk Assessment:

International Society of Arboriculture: Second
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Laurence R. Costello, Edward J. Perry, Nelda P.

Matheny, J. Michael Henry, Pamela M. Geisel.

Abiotic Disorders of Landscape Plants: A
Diagnostic Guide: University of California; 2003
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Irrigation: Irrigation Association: Sixth Edition;
2011
Michael A. Dirr. Manual of Woody Landscape
Plants: Their Identification, Ornamental
Characteristics, Culture, Propagation and Uses:

Stipes Publishing L.L.C.; Sixth Edition; 2009
Nelda Matheny and James R. Clark. Trees and
Development: A Technical Guide to
Preservation of Trees During Land
Development: International Society of
Arboriculture; 1998
Richard W. Harris, James R. Clark, Nelda P.

Matheny Arboriculture: Integrated
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Vines, Fourth Edition. : Prentice Hall; 2004

Cathedral City City CouncilSeptember 10, 2025

Cathedral City City Council
September 10, 2025