Helping trees recover from stress : a homeowners guide

28 Pages·2000·1.1 MB·English

by  Massachusetts. Dept. of Environmental Management

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Helping Trees
From
Recover
Stress
A Homeowners Guide
UMASS/AMHERST
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Digitized by the Internet Archive
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HELPING TREES
RECOVER FROM
STRESS
A HOMEOWNER GUIDE
'S
Produced By
Massachusetts Department
of
Environmental Management
ForestHealthProgram
ProjectFunded By:
The United States Forest Service
April 2000
To receive information onwoodyplant care, you
maycontactthe DepartmentofEnvironmental
Management's ForestHealth Program atthe
followingoffices:
Administration
Boston [phone]
Field Office [phone]
Region (SoutheasternMassachusetts)
1
Foxboro State Forest
45 Mill Street
MA
Foxboro, 02035
[phone]
Region2 (NortheasternMassachusetts)
Stow ServiceBuilding
RO. Box 224
MA
Hudson, 01749
[phone]
Region 3 (Central Massachusetts)
Regional Headquarters
P.O. Box 155
MA
Clinton, 015 10
[phone]
Region4 (ConnecticutValley)
Regional Headquarters
P.O. Box 484
MA
Amherst, 01004
[phone]
Region 5 (Western Massachusetts)
Regional Headquarters
P.O.Box 1433
MA
Pittsfield, 01201
[phone]
HELPING TREES
RECOVER FROM
STRESS
A HOMEOWNER GUIDE
'S
Contents Page
Introduction 1
Causes ofStress: An Overview 1
Symptoms ofStress 3
What the Homeowner CanDo 3
ProperPlanting Techniques 4
Caring forTrees 8
ProperPruning 8
Watering 10
Fertilizing 11
Mulching 12
Insect/Disease Control 13
When to Hire a Professional 15
Where to TurnforHelp 16
AdditionalReading 18

INTRODUCTION
Treesarethedominantcomponentinthenatural
andmanagedlandscape inNewEngland. Forthe
mostpart,treesinforeststhriveand, typically, live
morethanone hundredyears. Onthe otherhand,
treesplantedincities andtowns, andalongroad-
ways, oftensurviveno morethanafewdecades, if
that long. Thesetrees are subjectedto avarietyof
factorsthatreducevigorandmayeventuallylead
to decline anddeath. Almostallofthese factors
aretheresultofhumanactivity. Itisthepurposeof
thispublicationto introducethereadertothe
stressesimposedontreesgrowingincommunities
andaroundhomes, describethecommon symp-
toms ofstress, andsuggestwaystopreventor
reducethe impactofthese stresses ontrees.
CAUSES OF STRESS:
AN OVERVIEW
Mostpeoplebelievethatinsects anddiseases are
theprimarycausefordecline anddeathoftrees in
thelandscape. Infact, itishumanactivitywhich
causesmostoftheproblemsthattrees experience.
Evenmanypestanddiseaseproblems canbe
relateddirectlyorindirectlytothepriorstresses
imposedupontreesbyhumanactivity.
Theseactivitiesmayincludeimproperplantingand
pruningoftrees, aswell aspoorcare. Applying
toomuchortoo littlewater, especiallyafter
planting, mayinjureroots andcause stress. Over
applicationoffertilizercanalso leadtorootinjury
orrapidbutweakgrowththatmakesthe tree
proneto certaininsectpests andplantdiseases.
1
Mechanicalinjuriesfromlawnmowersandweed
trimmers candamagetreebarkandcreatethe
opportunityforinvasionbycertaindiseaseorgan-
isms. Excessivefootorvehiculartraffic around
trees candestroythe structure ofsoil leadingto
compactionofthatsoil. Compactionreducesthe
levelofoxygeninsoil, slowsthepenetrationof
water, andhindersthe developmentofroots.
Otherconsequencesofhumanactivity, especially
airpollutionandroadsaltapplications, arealittle
more difficultto assess andtoprevent. Forpeople
livinginareaspronetofrequentairpollution
events, thebestremedy, as farastree healthis
concerned, isto selectspeciesthatare somewhat
tolerantofcommonairpollutants. Similarly,
different speciesoftreeshavedifferenttolerances
to salts. Ifexposureto road salt is aproblem, salt
tolerantspecies suchasginkgomaybeplanted.
Diagnosingthe source ofstress onatree can
sometimesbedifficultbecausetreedecline israrely
causedbyone factoralone. It is more likelythata
combinationoffactorsareworkingtogetherto
causethe decline ofatree overaperiodofmany
years. The growingenvironmentofastressedtree
shouldbecarefullyevaluatedtodetermineasmany
ofthe causal factors aspossible. Check for
properplantingdepth andforgirdlingroots. The
pasthistoryofthetree shouldalsobereviewed.
Previousapplicationsofchemicals, recentperiods
ofdrought, extremelycoldoropenwinters,
floodingand similareventscanbe importantin
evaluatingsourcesofstress.
Nurseries and garden centers sell a greatvarietyof
trees, eachwith itsownspecific environmental
requirements. Landscape features such as soil
acidity, sun or shade, level of soil moisture and
drainage can influence how well a tree will
grow and prosper. It is important to match
these site features with the environmental needs
ofa tree before making a purchase.
SYMPTOMS OF STRESS
The symptoms of stress often develop slowly,
more slowly than insect or disease symptoms.
Some things to look for include: the appearance
ofabnormally small leaves, pale green colora-
tion ofleaves, unusually slow growth, prema-
ture development of fall leafcoloration, early
leafdrop, dieback oftwigs and branches,
wilting ofleaves and tender new growth,
peeling bark, and presence offungi protruding
from stems and branches. Repeated occurrence
ofthese symptoms over a period ofyears is a
good indicator that a tree is being subjected to
some chronic stress influences.
Some sources ofstress, e.g., a prolonged
drought, may reduce the vigor ofa tree, but if
provided with a good growing environment, the
tree may overcome this stress and resume
normal growth. However, should be noted
it
that it may take a tree several years to over-
come a single stress factor. Also, the effects of
drought on tree health may not become appar-
ent until 2 or 3 years after the drought event.
WHAT THE HOMEOWNER
CAN DO
Unfortunately, once symptoms ofdecline or
stress become apparent, it is often too late to
stop or reverse the damage to a tree. Therefore,
prevention is the best approach to eliminating
stress to trees. Prevention begins with proper
selection and planting, and continues with
regular inspection and care ofthese trees.
Proper Planting Techniques
Perhaps nothing is more important in prevent-
ing stress than the proper planting oftrees.
Research has shown that a tree planted at the
correct depth, in a hole of sufficient size to
accommodate the tree's expanding root system,
has a much greater chance of survival than
improperly planted ones.
Here are some rules to follow when planting
trees:
=>Locate trees away from high foot traffic
areas that may cause compaction of soil and
away from the street ifroad salts are routinely
applied during the winter. Avoid planting trees
where their roots may be confined, such as
close to a street, sidewalk or building. Also,
avoid planting trees beneath utility wires.
=>Evaluate the planting site with respect to
drainage, exposure to wind, amount of sunlight,
type of soil (sandy or clay), space for root
development, and soil pH. Also, note the
hardiness zone in which you live so that you
are sure to select a tree that will survive the
prevailing winter temperatures. Hardiness
USDA
zones in Massachusetts range from zone
7a on Cape Cod to USDA zone 4 in the Berk-
shires.