A guide to planting, watering
& maintaining healthy trees
Trees are landscape superstars, and we depend
on them to enhance our environment and quality
of life. They help clean the air, cool our homes
and buildings, replenish groundwater and create
beautiful, livable neighborhoods.
Though planting a tree may be a simple process,
following these step-by-step instructions will help
give new trees the best opportunity to establish,
grow and thrive. Creating resilient trees free of
common disorders or diseases starts with the
appropriate care, and we are here to help.
California Sycamore
PLANTING
01/
True root flare
Root ball
Circling roots
1
2
3
1 / Prep
1. Remove grass and plants in a 4-foot-wide area
of your landscape.
2. Dig a hole that is as deep as the tree’s root ball
and 2 to 3 times as wide, about 4 feet wide by
8 inches deep.
3. Remove the container from the tree by laying the
tree down on its side and putting pressure on the
sides of the container to loosen the root ball.
1
3
Prep continued on next page
Coast Live Oak
Remove the
container from
the tree, not
the tree from
the container.
2
4. Do not leave the root ball exposed to the sun and
air for too long, or the roots will dry out. If needed,
water the root ball and return it temporarily to the
container before planting.
5. Massage the root ball to remove extra soil and
loosen the roots for planting. You want the roots
to stretch out radially like bicycle spokes coming
out of the root ball.
6. Remove extra soil to expose the area where the
rst main roots attach to the trunk. This area is
known as the true root flare.
7. Prune off and straighten any large, circling roots
and add soil around them if they are exible.
TRUE
ROOT FLARE
PRUNE
CIRCLING ROOTS
Western Redbud
2 / Plant
1. Place the tree in the hole, paying
attention to the direction the branches
will grow. You don’t want branches to
interfere with buildings or street traffic.
2. If the tree is slanted, add soil
underneath the root ball to straighten.
3. Fill the hole with the same soil that
you removed from the area.
4. As you fill the hole, tamp down the
soil to remove any air pockets. Do not
stomp the soil in place. Instead, you
can use the back of a shovel to tamp
down, but make sure to leave space
for water to percolate into the soil.
5. The root flare should be the same
level as the soil.
SOIL
LINE
JUST
RIGHT
TOO
HIGH
TOO
LOW
Do not stomp
the soil in place.
18" 18"
1. Remove the nursery stake and ll the
hole with soil.
2. Place stakes on either side of the tree,
about 18 inches from the trunk. Then,
position them to hold the tree straight
when tied to the stakes.
3. Loosely loop the rubber ties around the
tree in a gure X. The tree should be able
to move 3 inches in the wind with the
ties on. The ties should be placed about
2/3 of the way up the tree trunk.
4. Nail both ends of the ties to the stakes
to secure.
5. Stakes and ties should remain until the
roots are established. This may take about
six months to two years. You will know the
roots are established when you can shake
the trunk and the ground does not move.
3 / Stake
NOTE: Installing stakes can be an arduous process
that involves climbing a ladder and hammering.
You may want an extra set of hands for this step.
Desert Museum
Palo Verde
4 / Water
& Mulch
1. Slowly water the tree with a bucket or
hose by pouring it onto the back of a
shovel directed at the tree roots.
2. After planting, give the tree about
15 to 20 gallons of water.
3. Add soil to any area where water
is escaping.
4. Spread no more than 6 inches of
mulch 4 inches from the trunk.
4"
6"
Use rubber ties or
horticulture tape.
They are flexible
and will give the tree
some wiggle room.
15 to 20 gallons
of water
after planting.
Notes
WATERING
02/
Do not rely on lawn sprinklers to water your
trees–they do not soak soil deep enough to
reach the tree roots. Trees absorb water at least
18 inches below the soil and out to the drip line.
The drip line is an imaginary line around the tree
that marks the edge of the tree canopy.
Watering
MULCH
DRIP
LINE
DRIP
LINE
Blue Elderberry
The best way to irrigate your trees is with a tree ring, or
in-line emitter hose spiraled outward from the tree in
concentric circles beyond the drip line. If possible, put
the tree on its own irrigation valve. Trees need deeper
but less frequent watering than other plants. A separate
irrigation valve may water the tree more effectively.
Watering Young Trees
1. The area around young trees
must always be kept moist to
help the trees establish.
One to three years after planting
Watering
2. While the tree is young, pack soil
around the tree to create a circular
mound. This creates a basin that
directs water to the roots. Extend
this mound to the drip line once a
year as the tree grows.
..........................................................................................................
..........................................................................................................
3. Place your nger or a screwdriver
4 inches into the soil to check for
moisture. If the soil is still wet,
don’t water.
5-gallon
4. Water young trees about once
a week using a 5-gallon bucket.
Slowly pour about three to
four buckets of water into the
tree basin.
Tecate Cypress
.
Watering
Established Trees
Three+ years after planting
1. After establishment, trees no longer need
to be kept moist. Allow the soil to dry out
between watering.
2. Water the tree once or twice monthly using an
in-line emitter hose. Due to the slow water rate
of this type of irrigation, this could take one to
two hours.
3. Water needs to soak into the soil until it reaches
about 12 to 18 inches deep. Continue to soak
until the water depth reaches that point. You
can use a soil probe or screwdriver to push
into the soil and check how far the water has
reached. When it doesn’t go down any further,
you have hit the dry layer.
4. Don’t water close to the trunk. Water should
be directed closer to the drip line of the tree.
California Bay Laurel
.
.
Water for one hour
and then check
soil moisture to
see if more time
is needed.
Notes
MULCHING
03/
Mulch acts as a protective barrier for tree roots.
It shields the roots from extreme temperatures
and discourages competition from grasses or
weeds. Add only natural and organic mulch
around your tree to help it grow and keep
moisture and nutrients in the soil.
Avoid using synthetic mulch material. Apart
from being highly ammable, it does not provide
the benecial nutrients your trees need. Some
organic mulch can also be highly ammable.
Mulch
RED DYED
WOOD MULCH
(dyes affect soil health)
BLACK DYED
WOOD MULCH
(dyes affect soil health)
GORILLA
HAIR MULCH
(highly flammable)
RUBBER MULCH
(synthetic & highly
flammable)
Blue Elderberry
TYPES OF MULCH TO AVOID
How to introduce mulch to your landscape:
1. Remove grass and weeds around the tree, especially
in the mulch area.
2. As an option, spread compost in the mulch area to
promote healthy soil.
3. Spread and layer mulch in the shape of a 4-foot
diameter doughnut around the tree. Lay mulch at least
4 inches from the trunk and avoid placing it directly
against the base of the tree. The mulch layer should
be about 6 inches thick. Spread mulch outward from
your young tree as it grows. For mature trees, spread
mulch further away from the base, at least 6 inches.
4. Replace mulch at least once a year as it breaks down.
Continue to remove plants, grass and weeds from
the area.
Mulch
Recommended
WOOD BARK MULCH
Do not place rocks, decomposed
granite, weed block fabric, or
synthetic turf around trees.
These materials increase water
runoff and trap heat in the
surrounding soil.
Replace mulch
at least once
a year as it
breaks down.
Argentine Mesquite
Marina Strawberry Tree
Notes
PRUNING &
WEEDING
04/
1. You do not need to prune for the rst three years.
After three years, prune every winter as needed.
2. Remove any competing branches that are the
same height as the main trunk.
3. Remove dead, diseased, and crossing branches.
4. Remove suckers, which are branches growing
from the ground or root are. If the suckers are
growing directly off the roots, remove the soil
rst and then remove the growth.
5. Remove all grass and weeds growing in a 3-to
4-foot-wide circle around the tree. Be sure to use
a small hand tool so only weeds are removed
without damaging the roots.
Pruning &
Weeding
Suckers are
branches growing
from the ground
or root are.
Western Redbud
Notes
GLOSSARY &
DEFINITIONS
05/
Tree canopy
The layer of branches and
leaves that cover the ground
when viewed from above.
Drip line
An imaginary line around the
tree that marks the edge of
the tree canopy.
True root flare
Where the first main roots
attach to the trunk.
Suckers
Small branches growing from
the ground or root flare.
Root ball
The main mass of roots located
directly beneath the plant's stem.
In-line emitter hose
Irrigation drip line that has built-in
emitters that spread water evenly
every set number of inches.
Torrey Pine
Argentine Mesquite
Hollyleaf Cherry
For Your
Waterwise Garden
TOP
A tree is dened as a woody perennial plant with many secondary
branches supported above the ground by one main stem or trunk.
• Trees must be planted
within the turf replacement
project area.
• Trees must be a minimum
size of 15 gallons when
purchased and planted.
• Trees are expected to grow
to at least 15 feet tall and
10 feet wide at maturity
(this does not apply to
edible fruit trees).
• Fruit trees are only rebate-
eligible for residential
properties, not commercial.
Rebate Requirements
Trees are natural helpers of the environment—they improve air quality,
capture carbon and reduce surrounding temperatures. That’s why
Metropolitan offers an extra incentive to include trees in your turf
replacement project.
You can now receive a $100 rebate per tree for up to five trees
planted while you replace your grass with a beautiful California
Friendly
®
landscape. Before you go to your local nursery or garden
center, use this recommended list to help identify trees that are a
good fit for your space and will thrive in Southern California’s climate.
Minimum
Planting Space
Maximum
Height
Crown/Root
Spread
Root Damage
Potential
Powerline
Friendly
Evergreen
All measurements
are in feet.
Water
Usage
Small California Native Trees
Common Tree Name
Species
Western Redbud
Cercis occidentalis
3' 25' 10-20' Low Yes No Moderate
Bubba Desert Willow
Chilopsis linearis ‘Bubba’
3' 20' 10-15' Low Yes No Very Low
Chitalpa
Chitalpa tashkentensis
3' 35' 20-30' Low Yes No
Low -
Moderate
Desert Museum
Palo Verde
Parkinsonia x ‘Desert
Museum’
3' 20' 20-25' Low Yes No Very Low
Blue Elderberry
Sambucus mexicana
3' 20' 10-20' Medium Yes No Low
Toyon
Heteromeles arbutifolia
4' 25' 10-15' Low Yes Yes Low
ChitalpaToyon
Desert Museum Palo Verde
Hollyleaf CherryCalifornia Bay Laurel
Common Tree Name
Species
Hollyleaf Cherry
Prunus ilicifolia
6' 30' 10-25' Low No Yes Low
Tecate Cypress
Hesperocyparis forbesii
7' 25' 15-20' Medium Yes Yes Low
Southern California
Black Walnut
Juglans californica
7' 30' 15-30' Medium No No Moderate
California Bay Laurel
Umbellularia californica
8' 80' 60-75' Medium No Yes High
Medium California Native Trees
What Not to Plant
Certain trees are not eligible for the
rebate. Here’s a list of what not to plant.
• Woody plants like tree-looking
shrubs used to create hedges
around a property.
• Plants bred or pruned to maintain a
reduced canopy. These plants are
commonly called topiary, espaliered,
or pollarded trees or shrubs.
• Small weeping varieties with soft
branches hanging downward and
touching the ground.
• Trees without spreading canopies
that do not provide substantial
shade or shelter when fully grown.
• All invasive tree species listed
by the California Invasive Plant
Council at cal-ipc.org.
• All palm varieties.
Large California Native Trees
Common Tree Name
Species
Incense Cedar
Calocedrus decurrens
10' 90' 10-15' Medium No Yes Moderate
Coast Live Oak
Quercus agrifolia
10' 70' 20-70' Medium No Yes Low
Engelmann Oak
Quercus engelmannii
10' 70' 80-120' Medium No No
Low once
established
California Sycamore
Platanus racemosa
10' 80' 20-50' Medium No No
Moderate -
High
Types of Trees to Avoid
Certain trees need a lot of water.
Others are vulnerable to disease or
pests, and some are not ideal for
fire hazard severity zones.
Other Trees to Consider
Torrey Pine | Pinus torreyana
California Ash | Fraxinus dipetala
Island Ceanothus | Ceanothus arboreus
The Best Fruit Trees for your Home
Catalina Cherry | Prunus ilicifolia ssp. lyonii
Pineapple Guava | Acca sellowiana
DISEASE & PEST PRONE
• American • Box Elder
Sweetgum
Coast Live Oak
HIGH WATER USE
• Mulberry
• Coast Redwood
• Fremont
Cottonwood
• European
White Birch
• Pine
• Eucalyptus
• Juniper
• Cypress
• Palms
HIGH FIRE RISK
Avoid if you are in a fire hazard severity zone
