If possible, take
a couple of digital photos of your tree or shrub and include them
with your questions. One photo should be a close up of the problem
area. The second photo should be of the entire tree if possible.
Information For Trees
details for trees in Cheyenne
There is a wealth of information
concerning watering trees, low water using landscapes, and water
saving ideas available at these Websites:
Information in General
The Environment and
Culture of Cheyenne's Trees
Historically the climate in
and around Cheyenne is defined by:
- Precipitation yearly average:
Approximately 15.50 inches
- USDA Plant Hardiness Zone:
Zone 4b to 5a - low temperatures usually not below
-20 degrees F.
- Record low temperatures: -30°F
occurring infrequently during December, January, and February
- Summer temperatures: 80's to low to mid 90's.
Record high of 100°F on
four different dates.
- Average date of last Spring temperature at
or below 32 degrees F: May 18.
- Average date of first Fall temperature at
or below 32 degrees F: September 25.
- Sustained, dry, winds year round.
Supporting vegetatively, a short
grass prairie, with native trees such as cottonwoods, willows,
and boxelders around areas of frequent or persistent water retention.
Typically trees will not grow in
this area without initial human support through watering, fertilizing,
wind protection, and insect and disease control. Trees that are
suited for USDA Hardiness Zone 5 and above are at risk of dying
during periods of record cold. Trees suited for zone 4 and below
are relatively safe bets for this climate.
Without initial human support, trees
under stress are easy targets for insect and disease attack.
Late spring freezes can cause significant
depletion of food reserves in the tree by killing emerging new
growth, forcing the tree to "push out" additional new growth.
Average last spring frost day May 18th.
Hail occurs frequently during the
spring and summer months in Cheyenne. Hail damages limbs and trunks.
Trees use energy reserves to compartmentalize hail damage. Hail
damage causes open wounds, easy access for insect attack, and
Early autumn moderate snowfall or
freezing rain can break limbs or entire trees due to snow and
ice accumulation on the tree leaves. Major limb breakage opens
the tree to insect attack and decay fungus infection.
Shallow rooted trees are weakened
or killed by yearly or cyclic periods of drought conditions.
Evergreen trees are susceptible to
death by dry and windy winters due to evapotranspiration that
occurs year round. Mechanical rubbing injury to limbs, twigs,
and needles is caused by wind.
Cheyenne's high elevation (~6,100
feet) means more intense sunlight, especially in winter when the
sun is low in the south and snow is on the ground. Direct and
reflective heating of the south and southwest side of tree trunks
results in higher chances of sunscald damage to young thin-barked
trees. Trunk damage from winter sun heating is also known as southwest
disease and sunscald.
Tree species selection in Cheyenne
is limited due to these conditions. Many of the broadleaf deciduous
trees that are growing well in Cheyenne are not very strong trees.
The cottonwoods, poplars, willows, Siberian elms, and soft maples
like boxelder and silver maple, are fast growing short-lived trees.
Fast growing trees usually equates to structurally weak trees.
Cottonwoods, poplars, silver maples, and willows can grow very
large limbs in a short period of time, 20 years. These fast growing
trees are more likely to acquire a wood decay fungus in the interior
heartwood of the trees. Frequently these trees will have large
hollow limbs or trunks initially caused by wood decay fungus.
Squirrels and cavity nesting birds take advantage of the decaying
wood by excavating it out of the tree to make a home for themselves.
Although structurally weakened, trees with hollow cavities in
limbs and trunks are critical habitat for birds and squirrels.
The challenge is to provide habitat for urban wildlife and to
keep trees safe for human activities below them.
The Siberian elm, commonly, but incorrectly
known as a Chinese elm, is an imported tree from Asia, initially
used to a great extent in wind breaks throughout the Great Plains
states. This tree species can grow just about anywhere and under
any condition. The life expectancy of Siberian elms is usually
40 to 60 years. They produce an abundant amount of seed that will
sprout anywhere including lawns, alleys, and in cracks in street
pavement. Most Siberian elms will still have green leaves at the
end of October. An exotic insect from Asia, the
banded elm bark beetle, is causing mortality in the Siberian
elms in and around Cheyenne. Trees retaining leaves into the snowy
months are more likely to suffer major limb breakage when snow
collects on the leaves and limbs. Since they are in green leaf
late into the season not only are they susceptible to snow damage,
they are susceptible to extreme temperature drops as well. The
Halloween freeze in 1991, when the temperature dropped from the
60's to below zero in a short period of time, killed or caused
extensive die-back in many Siberian elms in the northern Great
Trees: Facts and Info
Wyoming State Tree: Plains
Cottonwood, Populus sargentii Dode.
to 100 feet tall, 60-100 foot canopy spread, trunk
diameter up to 5 or 6 feet.
Minimum Ground Space: 15
feet diameter of open ground around a cottonwood tree trunk.
up to 100 years.
Female cottonwood trees: Produce
the cottony covered seed.
Male cottonwood trees: Produce
Wyoming State Tree - Plains Cottonwood,
Populus sargentii Dode. Dendrologists do not have
a consensus of opinion if the Plains cottonwood is a separate
species or a variety of eastern cottonwood - Populus deltoids
var. occidentalis. Cottonwood trees
are in the Willow family and the Poplar genus.
The plains cottonwoods, eastern cottonwoods and other true species
of cottonwoods are majestic and magnificent trees, especially
when they are allowed to reach their full, unrestricted growth
potential. Cottonwoods grow well in Cheyenne and in Wyoming in
general. Cottonwoods are typically found growing along streams,
irrigation ditches, and around lakes. Although they grow best
around a source of water, they can tolerate dry soils, if grown
in dry soils from the start. Cottonwood trees grow fast, can grow
large heavy limbs, are weak-wooded, are prone to wood decay, and
on average have a safe lifespan of 70 years. Additional information
on cottonwoods at
National Arbor Day Foundation.
Cottonwood trees are dioecious, which means they
have male and female flowers on separate trees. The pollen in
male flowers is ripe in late March and into April. Wind borne
tree pollen, including cottonwood pollen, is a major source of
allergy problems for many people. Cottonless
cottonwoods are clones of male trees, which have pollen. The
fruit of the cottonwood borne on the female tree is in the form
of a seed surrounded by a cottony substance, hence the name of
the tree -- cottonwood. Like the pollen, the seed is distributed
by the wind. The seed capsules open in late May through June.
Although the cottony-seeds can be a nuisance, they have NO
allergenic properties. People with allergy problems during the
time of the cottony-seed distribution are probably suffering from
other wind-borne pollen from grasses, weeds or late pollinating
trees. There are no Cheyenne city laws, nor any state statutes
prohibiting the planting of the female, cottony-seed bearing tree.
Tree nurseries typically do not sell the female, cottony seed
Plains cottonwoods in Cheyenne can develop a trunk
five feet in diameter (an example is on the 1200 block of West
Pershing). On average, the mature and over-mature cottonwoods
in Cheyenne have two and a half to three foot trunk diameters.
The upheaval of the soil around the base of the tree caused by
the root flair can be an additional three feet around the trunk.
Five feet of tree trunk with three feet of root flair on all sides
of the trunk can require an 11 to 15-foot diameter circle of ground
surface for unhindered tree trunk and root flair development.
The tree lawn area in the public right-of-way, the landscape area
between the street and sidewalk, should be at least 12 feet wide
to allow a cottonwood to develop to its full trunk and root flair
potential without damaging other infrastructure such as the sidewalk
and street. A cottonwood planted in a narrow or small ground site
will push up the sidewalk and curb near the tree, which requires
repair of the damage. Replacing curbs, gutters and sidewalks requires
cutting tree roots. Often, large roots will have to be cut. Trees
with cut roots result in structural stability problems for the
tree and diminished water and nutrient uptake by the tree, which
can cause a decline in tree health. A decline in tree health can
result in increased insect and disease attack, limb die-back,
or complete tree mortality. Damaged sidewalks can exclude wheelchair
use and restrict pedestrian use. More
info on Large Shade Trees.
Plains cottonwoods can develop a leaf canopy of 40 to
100 feet in diameter. Ideally, shade trees that can reach the
size of a cottonwood should be planted so that there is minimal
leaf crown interference with each other. A spacing of at least
40 feet between large shade trees is desirable.
All of us, as current stewards of the city, have
a responsibility to future generations to utilize our current
research, information, and technology to provide a functional,
sturdy, long-lasting infrastructure, which includes trees.
Cheyenne City Code requires that vegetation including
trees located in the public right-of-way abutting private property
is the maintenance and cost responsibility of the property owner.
Cottonwood trees, like historic buildings, require
maintenance. Tree maintenance includes: watering, occasional fertilizing,
treating insects and diseases, and pruning of dead, broken, weak
or diseased limbs. Maintenance can be expensive, especially pruning.
Federal funding through Community Development Block Grants (CDBG)
administered by Cheyenne Housing and Community Development at
307-637-6255, is available for low income families for removal
of trees only. Currently, there is no financial assistance available
for property owners to prune their trees. Pruning weak, broken,
and dead limbs off of a tree can extend the safe lifespan of trees
Responsible street tree planning requires species
diversity. A tree inventory/evaluation was done in 2004
in the central part of Cheyenne found that Populus species
trees (cottonwood, poplar, aspen) comprise 19.8% of the inventoried
Many eastern cities in the U.S. had streets lined
with American elms in the 1800's and into the early 20th Century.
In the mid 1930's a fungus commonly known as Dutch elm disease
was inadvertently introduced into the United States from Europe.
The fungus carried by a European introduced bark beetle, along
with native bark beetles, quickly spread Dutch elm disease throughout
the United States. Hundreds of thousands of native large leaf
elms were killed by Dutch
elm disease. Many cities lost all of the street trees
on many city streets that were previously shaded by the elms.
We learned from this introduction of disease and
insects that planting a wide diversity of tree species is required
to reduce the impact of catastrophic tree loss when a disease
like Dutch elm disease occurs again. We learned that the Dutch
elm disease could be spread from tree-to-tree not only by insects,
but by root grafts from nearby trees. To avoid same species root
grafts we try to avoid planting same species of trees near each
other, even if they are planted 50 feet apart. Tree roots can
grow in a radius from the trunk more than 1½ times the
height of the tree. If a tree mortality causing insect or disease
is introduced into the United States, which specifically attacks
cottonwoods, the city of Cheyenne could lose one fifth of all
our street trees. An unknown number of cottonwoods on private
property would also be lost.
Cottonwood trees can grow in a wide range of soil
types. Cottonwoods, in the same tree family as willows, are a
good pioneer type of tree for converting grass prairie land into
an urban woodland area. Other slower growing trees that have a
longer life can be planted in the shade of cottonwoods and in
the soils modified by cottonwoods. Although they do not grow well
in the shade of larger trees, cottonwoods can still be replanted.
Care needs to be taken to allow mixing tree species to avoid a
monoculture, which is a close grouping of the same species. A
planting plan for a healthy urban forest is to have a wide diversity
of tree species.
A Good Tree
Tree Spacing in the Public Right-of-Way
If they survive, trees will adapt to the situation
in which they are planted or growing. Most large mature trees
that grow in Cheyenne are capable of having a crown spread of
30 to 60 feet. Shade trees, or large trees at maturity, planted
less than 30 feet apart on trunk centers, have the following drawbacks:
- Intertwined tree crowns have
rubbing branches causing limb mortality or wounds where insects
and diseases can enter the tree causing decline or death. Rubbing
branches are structurally weakened and fail more frequently
than undamaged branches.
- Intertwined tree crowns cause
excessive shading in that crown intersection resulting in branch
die-back. If one of the trees dies or is removed, a large bare
area and a disfigured crown will exist on the remaining tree.
- Excessive shading from intertwined
crowns can promote fungal disease growth in the tree and on
plants below the tree. Grass development is limited in highly
shaded areas. In the winter, even when the leaves are not on
the trees, intertwined tree crowns have a higher shade factor
above the street, reducing solar melting of snow and ice from
- Trees in competition with
one another for sunlight will concentrate most growth in reaching
up for the sunlight, usually at the cost of growing trunk and
limb strength to support the rapid height growth.
- Shade trees have large trunks.
A row of closely spaced large trunks along the street causes
a visual wall, hampering the visibility of oncoming traffic
from street intersections.
- Trees planted close to one
another in an area already lacking sufficient ground surface
for water and air infiltration into the root zone, such as trees
planted along paved streets, compete with each other for the
limited supply of water and minerals. Trees in close competition
for limited minerals and water are growing under stress.
- Reasonable tree trunk movement,
swaying in the wind, actually promotes a stronger root and trunk
support system for the tree. Trees planted close together or
in groups have grown to depend on other nearby trees to damper
the wind. Individual trees growing in a closely planted group
of trees have not developed strong root and trunk support since
the strength is attained as a group.
- Tree root systems can grow
more than 1½ times the crown spread of the tree. Trees
planted close together can have roots that will graft together,
thereby establishing a link between the two trees. Contagious
diseases, such as Dutch elm disease, which has killed many closely
planted American elms in the past, can easily move from tree-to-tree
via root grafts.
shade trees require an area of ground that is at least the same
size as the mature crown spread. Ideally, a tree with a 40-foot
crown spread would require at least a 40-foot diameter area, or
1250 square feet, for unhindered root development. Ideally, the
tree crown should not touch any other tree or object to allow
the full potential of crown development
Conifer Trees Planted
Along the Street
Conifer trees, (e.g.,pine, spruce, juniper, fir)
when planted along the street eventually overgrow the width of
the planting strip known as a tree lawn, the area of landscape
between the street and sidewalk. Required sidewalk height clearance
in Cheyenne is eight feet. The required street height clearance
is 14 feet. In addition no branches should protrude into the sidewalk
and street area. A conifer is a cone-bearing tree. Typically in
Cheyenne it is an evergreen with needle shaped leaves. City
ordinance 12.16.020 prohibits the planting of conifer trees in
the tree lawn area.
The growth form of conifer trees is to retain
branches low to the ground. Branches low to the ground can grow
out from the trunk in a radius of 5 to 15 feet. For example a
large spruce tree with low growing branches can cover an area
of ground 20 to 30 in diameter. Most tree lawns in Cheyenne are
6 to 12 feet wide. Pruning a conifer tree to provide the clearance
required for street and sidewalks can cause the conifer tree to
be unsightly, unhealthy, and in some cases predisposing the tree
for failure due to wind. Conifers planted on the south side of
streets can shade the street surface in winter causing icy conditions
on the street. Conifers planted on the north side of street can
cause snow drifts into the street. Conifers obstruct the vision
of drivers. Pedestrians, especially children, cannot be seen by
drivers when they are entering the street from behind a conifer.
Although the small conifer is small when purchased
and planted, and for a period of time fits well in the tree lawn,
the future brings nothing but problems for conifers growing in
Cheyenne Street and
Park Tree Inventory / Evaluation - 2004
The Cheyenne Urban Forestry Division contracted
with Davey Resource Group, which is a division of The Davey Tree
Expert Company, to evaluate street trees in the older part of
Cheyenne and to evaluate trees in Airport Golf Course and in Lions,
and Holliday Parks. The cost of the tree evaluation was $40,000.
Wyoming State Forestry Division awarded the city a $35,000 grant
for the inventory / evaluation and the Cheyenne Urban Forestry
Division paid $5,000. The evaluation process began in August 2004
and ended in October 2004. We received the data and Management
Plan in November 2004.
The evaluation included: A Geographic Information
System (GIS) mapped location for each tree. A determination of
tree condition and management needed for each tree. A monetary
value calculated for each tree. And a management plan to address
the needs of the individual trees and the urban forest in general.
The complete Management Plan can be seen by clicking here: Street
and Park Tree Evaluation for Cheyenne. The
plan is 314 pages long and may take several minutes to load.
of the 2004 inventory are: On the North - W. 8th Avenue, Evans
Avenue and Pershing Blvd. to Converse Ave, On the East - Converse
Avenue, On the South - the railroad tracks, and On the West -
the residential area to I-25. Davey Resource Group evaluated 19,315
total sites which include: 7,718 street trees, 114 stumps along
the streets and 973 possible planting sites along the streets
(Since the cost of the tree evaluation was based on a per tree
cost and per site cost, there are actually many more possible
planting sites above the 973 identified). There are 11210 total
trees (includes 709 trees planted Fall of 2004 after the inventory
was complete) in city maintained public areas including parks,
golf courses, cemeteries, Greenway, and around city buildings.
The park tree total includes city maintained areas previously
evaluated by Cheyenne Urban Forestry arborists last year.
the tree evaluation determined:
19,315 total sites which include: 7,718 street trees,
973 possible planting sites along the streets (Since the cost
of the tree evaluation was based on a per tree cost and per site
cost there are actually many more possible planting sites above
the 973 identified), and 114 stumps along the streets. There are
10,501 total trees (not including 709 trees planted Fall of 2004
after inventory was done) in city maintained public areas including
parks, golf courses, cemeteries, Greenway, and around city buildings.
The park tree total includes city maintained areas previously
evaluated by Cheyenne Urban Forestry arborists last year.
The total value of the inventoried part
of Cheyenne's street trees and the entire park tree population
is estimated to be $34.5 million.
There were 123 different tree species identified.
Most species diversity was found in the Cheyenne Botanic Gardens.
Populus species (cottonwood, poplar,
aspen) comprise 19.8% of the inventoried tree population. Picea
species (spruces) comprise 15.4%, Pinus species (pine)
13.5%, Fraxinus species (ash) 10.0%, Ulmus (elm)
8.2%, Malus species (crabapple and apple) 5.6%, Prunus
species (cherry and plum) 4.7%, Gleditsia species (honeylocust)
4.5%, Acer species (maple) 4.3%, and Juniperus species
(juniper) contributing 2.9%. These ten top genera comprise
88.9% of all the trees evaluated.
Here are two good websites pertaining to tree
State University Cooperative Extension
Shade Trees in Landscapes
ARBORISTS and PESTICIDE APPLICATORS
This list constitutes the arborists
that are currently licensed and insured according to the City
of Cheyenne Ordinances. The Urban Forestry Division cannot endorse
the quality of work of any company or individual on any
particular tree/shrub. The Urban Forestry Division suggests that
consumers obtain several estimates, check references, and enter
into a written contract before tree work begins.
As of April 1, 2006, all commercial
arborists in Cheyenne are required to be Certified Arborists or
Certified Tree Workers through International Society of Arboriculture,
to be licensed in the City of Cheyenne.
The commercial arborist companies below have an
Society of Arboriculture - Certified Arborist
on staff, and are licensed by the city.
Applicators Certified by the State of Wyoming
Licensed by the City of Cheyenne
Arbor Solutions: 307-634-5319
Cheyenne Tree Service: 307-632-3327
Davey Tree Expert Company: 970-223-4597
Evergreen Tree Care: 307-246-3343
Lawn & Tree Care: 307-634-2375
The Exterminator: 307-772-7500
Hi Lawn & Tree Care: 307-635-8472
R & R Spraying: 307-632-2330
Tree Inc: 307-460-4767
Industries: 635-2978 (Does not spray for Mountain Pine Beetle or residential properties)
Commercial Arborists and Pesticide Applicators
Every year, Cheyenne homeowners are inundated with advertising
offering cut-rate deals from contractors for tree and lawn care
services. As a service to homeowners, the Cheyenne Urban Forestry
division would like to offer these consumer tips.
- Request proof of licensing and insurance:
All tree care and spraying operations legally operating in the
City of Cheyenne must be licensed through the City Clerk's office
and must have adequate insurance coverage. In addition, spraying
operations must be able to show a current State of Wyoming Pesticide
Applicator's License. These requirements are for your protection
and do not necessarily increase the cost of a job. Avoid non-licensed
and uninsured companies, as you have no legal recourse should
damages occur. If an uninsured worker injures themselves on
your property, you will most likely have to pay the medical
- Ask for written estimates: Obtain several estimates,
compare the work specified, and the completion date. If your
trees are to be sprayed, find out what insect the company is
spraying for and what time of the year is the optimum time to
control that insect. Most insects are only effectively controlled
during certain growth stages, therefore only certain times of
the year. Beware of individuals that required payment "up front".
Services should not be paid for until all work is completed
to your satisfaction.
Call the forestry office (307-637-6428) to obtain
a copy of the free International Society of Arboriculture brochure
" Why Hire an Arborist".
Lions Park Tree Walk - Available in Cheyenne
Urban Forestry Office in Lions Park.
Drought and Trees - Developed by Cheyenne Community Forestry
Mountain Pine Beetle in Our Community
High Plains Aboretum Guide
Basic Tree Care for
Publications from International Society of Aboriculture:
in Cheyenne Urban Forestry Office in Lions Park.
City Boulevard Tree Care Responsibilities
Why Hire an Arborist
Mature Tree Care
Why Topping Hurts Trees
Benefits of Trees
Buying High-Quality Trees
Several other brochures and informational
papers are available and too numerous to list covering insects,
diseases, planting, pruning, iron chlorosis, and tree maintenance.
Available in Cheyenne Urban Forestry Office in Lions Park.