EC 1457September 1995$1.50

Stand Management

Pruning to Enhance Treeand Stand Value

W. Emmingham and S. FitzgeraldT OF D

ATE.

/catal

og

THIS P

UBLICATIO

N IS O

U

For mos

t curr

ent in

formati

on:

http:/

/exten

sion.o

regon

state.

edu

1

. 3..... 3...... 3

4..... 4...... 4

4..... 4....... 4..... 5...... 5

.. 6

..... 6

..... 6

..... 6

..... 8

....... 8

.. 8

..... 8.... 8..... 8...... 8..... 9..... 9

11

11..... 11

. 11

2

T OF D

ATE.

tion:

state.

edu/c

atalog

Contents

Why Should You Prune ..........................................................Other objectives of pruning ...................................................................Pruning is intensive management ........................................................

Basics of Wood Quality in Trees and Stands .........................Knots and wood quality .........................................................................Stand and branch development and self-pruning .................................

Pruning Management Options ................................................Choose stands carefully for pruning .....................................................What species can be pruned? ..............................................................Deciding on a pruning strategy .............................................................Core size ...............................................................................................

Basics of Tree Pruning ...........................................................Pruning lifts ...........................................................................................What about high pruning? .....................................................................

Combining Pruning with Other Management Operations ... 6Thinning ................................................................................................Fertilization............................................................................................Pruning in uneven-aged management systems ...................................

Pruning Mechanics .................................................................Identifying trees to prune ......................................................................What’s the optimum pruning diameter? ................................................How many trees to prune ......................................................................Sunscald and epicormic branching ......................................................Where to cut the limbs ..........................................................................Time of year to prune ............................................................................

What about Tools? .................................................................

Long-term Considerations .....................................................Is there cost-share assistance for pruning? .........................................

Summary ................................................................................

For More Information ............................................................ 1

THIS P

UBLICATIO

N IS O

U

For mos

t curr

ent in

forma

http:/

/exten

sion.o

regon

2

Pruning to Enhance Treeand Stand Value

W. Emmingham and S. Fitzgerald

h

THIS P

UBLICA

TE.

For mos

t cur

http:/

/exten

twtahrtbl

patPsfL

P

aftatutl

Why ShouldYou Prune?

Pruning removes the lowerbranches of young trees and allowsthe early formation of clear, knot-freewood. It is done to increase tree andstand value. In the Pacific Northwest,pruning operations are increasing onnonindustrial private land, timbercompany land, and state and federallands.

Recent lumber manufacturingstudies show that the value of lumbercut from pruned logs can more thanpay for the cost of labor and intereston the money invested in pruning.The value increase depends upon asawmill’s willingness to pay premiumprices for pruned logs—a trend thatseems increasingly likely.

However, like all forestry invest-ments, pruning must be considered acalculated risk because future marketsare unknown. Best estimates indicatethat pruning 100 trees per acre for one16.5-foot log at age 20 will producean added $6,000–$10,000 per acrewhen harvested 40–80 years later.

TION IS

OUT O

rent in

formati

on

on.or

egon

sta

3

i

Pruning currently is used to lessenhe impact of blister rust in younghite pine stands. It also may reduce

he incidence of foliage diseases, sucs Swiss needle cast, that thrive inumid environments. Pruning also caneduce dwarf mistletoe infections ifhe mistletoe is confined to the lowerranches, and the overall infection

evel in the stand is moderate to low.In this publication, we focus on

runing even-aged forest stands thatre being managed primarily for

imber volume and high value.runing regimes used in agroforestryystems are discussed in Agro-orestry: Growing Trees, Forage, andivestock Together, EC 1114.

F DA

:

te.ed

u/cata

log

William Emmingham, Extensionsilviculture specialist, and StephenFitzgerald, Extension forester, DeschutesCounty, Oregon State University.

Other objectives of pruningAlthough pruning is done primarily

to enhance clear wood production andtree value, it can fulfill other land-owner objectives as well. Forexample, pruning can increase fireresistance by removing “fuel ladders.”It also can improve access into densestands. Many owners simply like thelooks of a well-pruned stand.

Pruning also can increase theamount of light beneath the treecanopy, which enhances grass andforage production. This is especiallyimportant in intensive agroforestryoperations where livestock and high-value trees are grown and managedtogether for added income.

s

runing is intensive managementBecause pruning is a technique for

dding value to trees growing inorest stands, you can think of it ashe woodland manager’s “value-dded” effort. It is, however, a long-

erm investment; for example, evennder favorable tree growth condi-

ions, it takes 20 years to add a 5-inchayer of clear wood on a tree.

Pruning also is a laborious andcostly operation. For example,pruning 100 selected trees per acrelikely would take you several days ofhard work, or it could cost $150–$250if you hired a contractor to completethe work.

y

g

Basics of WoodQuality in Treesand Stands

Knots and wood qualityAlthough many factors cause

defects in lumber, knots are theprimary reason for reductions inlumber grade. A knot is the portion ofa branch that becomes incorporatedwithin the bole of the tree.

Knots can be of two types:ingrown or encased (see Figure 1).Ingrown knots are “tight” becausethey develop when the branch is aliveand the wood of the branch is ingrownwithin the tree bole.

Encased knots are loose becausethey develop after the branch dies andthe wood of the bole grows around thedead branch. Encased knots reducelumber quality more than tight knots.

Clear wood does not form until theentire pruning wound is covered over.This may take 1 to 10 years,

depending on species, site, tree vigorbranch size, stub length, and qualityof pruning work.

4

S t

result, branches stop growing and dieat a small size. In contrast, widespacings (e.g., 14 x 14 foot spacing)delay crown closure, allowingbranches to live longer and growbigger, resulting in large knots.

,

f

PruningManagement Options

Choose stands carefully for pruningSince pruning is a large investment

and payoff is many years away,evaluate potential stands carefully.Not every stand can be prunedprofitably, so you should prioritizestands to be pruned.

Select stands on your moreproductive sites: e.g., site class threeor better. They should be accessiblefor workers and preferably on gentletopography, making multiple thinningentries easy. Stands should be healthand vigorous.

Do not prune stands on exposed,wind-throw-prone areas such asridges, or sites with a high watertable. Avoid pruning stands with highincidence of root rot. Anything thatwould jeopardize growing the standfor several decades should raiseserious questions about the wisdom opruning that particular stand.

r

d

OF D

ATE.

on:

state.

edu/c

atalo

What species can be pruned?Douglas-fir and ponderosa p

good candidates for pruning. Rstudies show that pruning thesspecies can be profitable if milwilling to pay for the value in plogs.

The market value of other sis less certain, but species sucwestern larch, western hemlocwestern white pine, and noble considered good candidates fopruning. Most species of conifebe pruned, although some (e.glock, true firs, and spruce) are prone to invasion by wood-decfungi. In contrast, both ponderopine and Douglas-fir are quiteresistant to invasion by such fu

We know much less about pnative Northwest hardwoods, bvalue of clear wood is much hithan for conifers. Pruning red abigleaf maple in managed stanpay off as local markets for har

ingrown ortight knot

bark

clear woodcylinder

tight knotcore andDOS

pith

Figure 1.—A pruned and an unpruned log. Note the knotty core, diameteroutside stub, ingrown and encased knot zone, and cylinder of clear wood.

tight knotzone

encased orloose knots

ingrown ortight knots

pith

THIS P

UBLICATIO

N I

For mos

t curr

ent in

forma

http:/

/exten

sion.o

regon

Stand and branch developmentand self-pruning

The number and size of knots on atree are determined to a large extentby site productivity and stand densityand development. Natural or self-pruning of lower branches in foreststands is a slow process. It has threedistinct steps: branch death, branchshedding, and healing over of thebranch stub.

The self-pruning process is greatlyinfluenced by initial stand density andshade tolerance of the tree. At narrowspacings (e.g., 8 x 8 foot spacing),crown closure (when branches fromadjacent trees overlap) occurs soonethan at wide spacings. This increasesthe speed of branch death and crownlift (the process of progressive upwarbranch death) because of the intenseshading by branches from above andfrom adjacent trees (Figure 2). As a

OUT

i

ine areecentels areruned

peciesh ask,fir arerrs can., hem-moreayingsa

ngi.runingut

gherlder ords mayd-

woods continue to develop.

arket

T

IO

A

for ns

g

Figure 2.—Effect of tree spacing on crown lift, branch, and bole diameter.

Stand development

Narrow Wide

Tim

e

HIS P

UBLICAT

For mos

t curr

ent in

http:/

/exten

sion.o

rego

Deciding on a pruning strategyPruning is part of an intensive

management operation and should beplanned and carried out systematicallyonly in stands you intend to manageintensively.

The basic objective of pruning is tominimize the knotty core of wood inthe most valuable butt log of the tree.First, target a maximum knotty coresize, and prune when the tree reachesthat size. Second, decide what lengthof log you wish to market. Third,coordinate the pruning regime withthe thinning regime, because densitymanagement is the main tool forkeeping the tree’s diameter growth ata desired rate. To chart your ownstrategy, you will have to makedecisions based on an array of factorswhile keeping your objectives inmind.

Core sizeThe knotty core is measured as the

diameter outside stub (DOS), that is,to the point where the branch is cut(see Figure 1). Mills commonly peellogs down to a 4-inch core, andsmaller cores of about 2 inches arenow possible.

lmvHal

w

Strategies for keeping the DOSsmall include pruning in multiple lifts.How high you prune depends on howwilling you are to gamble your workor labor costs on the uncertain futurelog market.

Logs are sold in a variety ofengths to different end users. Conifer

ills that peel or slice clear boles intoeneer use short logs of 17 or 25 feet.ardwood mills buy multiples of 10nd 12 feet. Mills manufacturing

umber look for longer logs.It is worth noting that conifer logs

ith any knots (even small ones)

qCym

cmnDcstlN IS

OUT O

mation

ta

5

ualify only as number 2 sawlogs.urrent prices (see Table 1) can giveou a general idea of value, but futurearkets may vary considerably.The values in Table 1 are for

omparison purposes only. Whenarketing pruned logs, alwaysegotiate a special price based on theOS, growth rates, and other qualityharacteristics of the logs from yourtand. Remember, log grades usedoday were not developed with prunedogs in mind.

F D

:

te.ed

u/cata

lo

Table 1.—Conifer log lengths and grades: Current markets.

Length Quality Grade Relative Price(feet) (% of #2 sawlog)

16 + trim very knotty utility 3016 + trim knots over 2" #3 sawlog 8716 + trim few knots special mill 13325 + trim no knots, 6 rpi peeler 17332 + trim knots less than 2", export 190

< 8 rpi32 + trim knots less than 2" #2 sawlog 100

Note: These market values are given as examples of relative value only. Mvalues change daily, and over time, the relative value also may shift.

TE.

g

Basics ofTree Pruning

In pruning trees, you may removeboth live and dead branches. Remov-ing dead branches doesn’t affect thetree’s photosynthesis “factory” or treegrowth. Removing live branches doesaffect the factory, so be careful toleave the tree with an adequate crown

A general conservative rule ofthumb that applies to all tree sizes andspecies is to leave 50 percent of thetotal tree height in live crown(Figure 3). This is particularlyimportant on trees less than 30 feettall.

hoi831l

1l8tttsa

UB cu

.

eight of 18.5 feet and a target DOSf 8 inches often can be accomplished

n one lift. By the time trees reach inches dbh, they usually are over7 feet tall and can be pruned to8.5 feet while retaining 50 percent

ive crown.With a 4-inch target DOS and an

8.5-foot pruning height, we need ateast two lifts. The first could be to feet when the tree is about 18 feet

all. The second could be done whenhe tree grows to 37 feet. Differentree species or trees grown at widepacing will have different diameternd height growth characteristics, so

adjust your pruning lift scheduleaccordingly.

t

,

httunPWai

tmfttsdgfod

What about high pruning?Most pruning operations limit

pruning to 18.5 feet because pruninghigher gets more difficult andexpensive. Some foresters pruneconifers to 36 feet so the entire35-foot butt log is a high-value peelerlog. This requires a minimum of atwo-lift operation to prevent removingtoo much live crown at any one lift. Italso requires much more effortbecause pruning beyond 18.5 feetrequires high climbing or using morespecialized equipment such as amechanical “tree monkey.”

The decision to prune to greaterheights depends on your stand, sitequality, and how long you plan towait before final harvest. Limit highpruning to productive sites wheretrees grow tall in a relatively shortperiod of time.

ATION IS

OUT

rrent

inform

atio

n.oreg

ons

6

io

CombiningPruning withOther ManagementOperations

ThinningPruning and thinning operations

should be coordinated. Use earlythinning (commercial or precom-mercial) to maintain vigorous andsteady diameter growth that will healpruning wounds quickly and maxi-mize clear wood growth. A good timeto start pruning is right after earlythinning.

In a well-stocked stand, limbs aresmall and easy to remove. Small knots

eal over quickly. Carefully selectrees to prune at this time becausehey need to survive and grow wellntil harvest 20–50 years later (seeext section). See EC 1189, Usingrecommercial Thinning To Enhanceoodland Productivity, for tips on

voiding problems such as Ips beetlesn pine or sunscald in Douglas-fir.

Prune only the best future croprees in the stand (Figure 4). Thiseans you should prune only well-

ormed dominant or codominant treeshat can be favored (to leave) in futurehinning operations. These treeshould have full, healthy crowns andemonstrate good diameter and heighrowth. Trees should be straight and

ree of defects such as stem decays,ld logging wounds, and other visibleamage.

OF D

ATE.

n:

tate.e

du/ca

talo

Figure 3.—As the tree grows, each successive lift removes the branches below the 50 percent live crown level.

50%livecrown

16'

24'

37'

8'

12'

18.5'

TIME 3Third lift

TIME 2Second lift

TIME 1First lift

Three-lift Operation

50%livecrown

50%livecrown

THIS P

For mos

t

http:/

/exten

s

Pruning liftsLet’s assume your objective is to

prune half the trees in a young standto 18.5 feet. You could prune to thatheight all at once, but to maintain50 percent live crown, the tree wouldhave to be at least 37 feet tall. By thetime a pine tree is 37 feet tall, itusually is 8–12 inches dbh. If yourobjective is to maintain a knotty coreof 4 inches, it makes sense to prunethe same tree several times.

Each time you prune to a higherlevel, you give the tree another “lift.”Intensive pruning operations use twothree, or more lifts, depending ontarget pruning height, pruning toolsused, and size of operation.

As target DOS is reduced, thenumber of lifts needed to prune to agiven height increases. For example,with Douglas-fir, a target pruningLIC

T

suitablesuitable suitable suitable

forked crooked

forkedcrooked

Stand before thinning and pruning

T OF D

ATE.

catal

og

visiblee

S OUtio

n: .edu/

Stand after thinning and pruning

Figure 4.—Select the best trees in a stand to prune. Avoid pruning trees with forked or crooked tops or those withdamage. In this case, all trees left in thinning were pruned; however, often only the long-term, “final” crop trees arpruned.

HIS P

UBLICATIO

N I

For mos

t curr

ent in

forma

ttp://e

xtens

ion.or

egon

state

7

h

g

Commercial thinnings over timewill ensure continued growth of thehigher value pruned trees and provideperiodic income. Commercialthinning 10 to 20 years after earlythinning ensures that the pruned treesstay in a competitive crown positionand have the best chance of remaininvigorous and healthy until harvesttime.

In thinnings, remove unprunedtrees that are defective or crowdingpruned trees. If you carefully selectedthe best trees to prune early in therotation and favor them (to leave) inthinning, they should remain the besttrees in the stand.

e

FertilizationWhen trees are well spaced,

nitrogen fertilizer often can increasediameter growth beyond that fromthinning, producing added clear woodand value. However, before investingin large-scale fertilization, check tosee if your site and stand are goodcandidates. Check with adjacentowners or with the Natural ResourcesConservation Service to see if standson your soil type have respondedpositively to fertilization.

Generally, thinned stands respondbetter to nitrogen fertilizer thanunthinned stands. Fertilize ponderosapine and Douglas-fir at a rate of abou200 pounds of nitrogen per acre.

Growth response from fertilizationusually lasts 5 to 10 years dependingon tree species and site and standconditions. Therefore, fertilize about8–12 years before a thinning or finalharvest operation. This minimizes thetime until dollars invested in fertilizercan be regained in increased timbervalue. Contact a State Serviceforester, an Extension forestry agent,or a private consultant about fertiliz-ing and thinning your stands.

IS P

UBLIC

ost c

u

t

x Pruning in uneven-agedmanagement systems

Pruning also is compatible withuneven-aged management regimes. Igroup selection systems, the trees ingroups are managed as small even-aged patches. Therefore, the sametechniques discussed above aredirectly applicable.

In single-tree selection systems,where trees of all sizes and ages aremixed together, the same basicsapply. Choose the long-term crop

THFor

m

http:/

/e

g

trees and prune them in successivelifts. Since the probability of damag-ing smaller trees during repeatedpartial cutting operations is higher inthis system, consider pruning extratrees. As with even-aged regimes,give special attention to trees selectedfor pruning, and favor them (to leave)in all subsequent thinnings. Be sure tocontrol logging operations to mini-mize damage to pruned trees.

t

Pruning Mechanics

Identifying trees to pruneTrees to be pruned may be identi-

fied ahead of time or at the time ofpruning. With proper training, thepruner can select and prune the croptrees. The select-and-prune approachavoids the extra time and/or expenseinvolved in visiting each tree or standtwice. On the other hand, preselectionrelieves forest workers of thatresponsibility so they can concentrateon removing limbs.

It is a good idea to permanentlymark pruned trees so that you, otherforest workers, and potential logbuyers can identify them easily—even20 to 40 years later. Plastic or metaltags or tree marking paint are the moscommon methods for long-term treeidentification. Such efforts do, how-ever, add cost and time.ATIO

N IS O

UT

t infor

matio

gons

n

What’s the optimumpruning diameter?

Hardwoods up to 4 inches indiameter and conifers up to 8 inchesin diameter are excellent candidatesfor pruning; smaller trees are evenbetter. The upper limit for pruningdepends on how long the stand will beheld and how it is managed.

Delaying pruning and/or prema-turely harvesting pruned treesdecreases clear wood and increasesthe relative volume of knotty wood inthe center core. However, trees over10 inches can be pruned if allowed togrow to a large size (i.e., greater than20 inches).

rren

ensio

n.or

How many trees to pruneRemember the first basic rule of

pruning: don’t prune too many trees.You will reap little benefit frompruning every tree in a dense youngstand, because some will die or be

8

t

thinned out before they produce verymuch clear wood.

For example, a Douglas-fir standprecommercially thinned to 200 treesper acre can grow to only about14 inches average diameter before itshould be thinned again. If notthinned, the growth of individual treeswill slow, and, before long, sometrees will die from competition.

If these 200 trees per acre had anaverage diameter of 6 inches whenpruned, there would be only a 4-inchlayer of clear wood on a 14-inch tree.This may not bring a high premium atthe mill.

On the other hand, if this samestand is then commercially thinned to130 trees per acre when the averagetree reaches 14 inches in diameter, theremaining trees can continue to growto about 19 inches in diameter withoutserious competition. The largest halfof these trees will be 20–26 inchesdbh.

A final thinning leaves 85 trees peracre. If these final crop trees had beenselected and pruned after theprecommercial thinning when theaverage diameter was only 6 inches,and the dbh at final harvest is28 inches, this would result in an11-inch layer of clear wood around asmall knotty core. Obviously, thepremium paid for such a log would besubstantial.

From this example, you can seethat pruning too many trees could be awaste of time and money becausesome will die or be thinned out,unless pruning every tree fulfills someother objective. In summary, depend-ing on the target harvest diameter,only a certain number of trees can begrown to a large size. This dependssomewhat on the species and growthpotential of the site, but it probablywill be 100 trees per acre or fewer.

OF D

ATE.

n:

tate.e

du/ca

talo

Sunscald and epicormic branchingRemoval of branches exposes the

thin or immature bark on young treesto direct sunlight, which may causesunscald. Sunscald results when thesun heats the bark to lethal tempera-tures, killing the growing tissue calledcambium beneath the thin bark. Often,this occurs on the south and westsides of the tree as the sun shinesdirectly on the bark in late afternoon.

Over a period of years, sunscaldcreates a wound, making the tree

.

T

I

O

more susceptible to insects and fungi.Severe sunscald can kill portions ofthe tree above the wound.

Susceptibility to sunscald varies byspecies. True firs are very susceptibleDouglas-fir is intermediate, andponderosa pine is resistant to sun-scald.

Exposing the bark of some treespecies to sunlight also can stimulatedormant buds within the bark toproduce new (epicormic) shoots.These new shoots can producebranches and negate the benefits ofpruning if adequate light is available.Douglas-fir, grand fir, and all hard-woods produce epicormic branches.Ponderosa pine and larch do not.

Problems with sunscald andepicormic branching generally occurwhen dense stands on south slopessuddenly are opened up by thinning.Removing too much crown withexcessive or severe pruning also canaccentuate sunscald and epicormicbranching.

However, pruning in two or morelifts leaves the lower bole shaded,which helps prevent sunscald andminimizes epicormic branching onsmall-diameter trees. Leaving a fewbranches on the south and west side the tree also will help preventsunscald.

HIS P

UBLICAT

For mos

t curr

ttp://e

xten

h

,

On exposed, hot, south slopes, thinlightly so as to open up the standslowly, or delay pruning for a fewyears to let crowns recede and bark tothicken. Finally, don’t combinethinning and pruning operations in thesame year. S O

UT

tion

of

Where to cut the limbsCutting off dead limbs has no

effect on the tree as long as you donot injure the living bark. Pruning offlive branches will not injure the treeseriously if they are from the lowercrown. Lower branches having fewvigorous needles do not contributemuch to the tree’s energy and are oflittle value to the tree.

Remember, when cutting offbranches it is important to avoidinjury to the bole of the tree and thebranch collar (Figure 5). The branchcollar is the swollen area at the baseof the branch. Cut branches outsideany enlarged branch collar and nevercut flush with the bole. By cuttingonly the branch, the tree will healfaster, because the wound diameter issmaller.

Another reason for not cutting offthe branch collar is that the branchcollar is part of the tree bole. If decayenters the wound, it can spread arounthe bole. If decay enters the branchcut, it generally spreads only withinthe branch stub. Cutting outside the

ION

ent in

forma

sion.o

regon

sta

9

branch collar results in less pitchingbecause less live wood is injured.

Never treat pruning wounds witha wound dressing or paint. Studieshave shown that paints and wounddressings sold in farm and gardenstores actually trap moisture behindthe dressing and promote the growthof wood-decaying fungi.

:

te.ed

u/ca

Figure 5.—Remove branches properly to minimize damage to the branch collar.

correct incorrect incorrect

cut branchcollar

stub toolong

branchcollar

F DATE.

talog

d

Time of year to pruneThe best time of year to prune is

during late summer, fall, and earlywinter when the tree’s cambium is notactively growing. This helps minimizebark injury and pitch flows. In mostcases, however, you can prune at anytime if you take great care to avoidinjury to the main bole of the tree.

In some locations (e.g., WillametteValley), pruning wounds can attractinsects, such as the sequoia pitchmoth, to ponderosa pine andDouglas-fir. Female moths typicallyfly from late spring until early Augustand are attracted to trees pruned atthis time. Female moths lay their eggsin the pruning wounds, where theeggs hatch. The larvae burrow underthe bark, injuring the tree and creatingmassive pitch pockets, which degradethe wood quality and weaken the treeDelaying pruning until fall, after themoths have left, helps avoid attractingthese insects to your trees.

Saws

short-handle pruning saw

hand saw with chainsaw-type teeth

long-handle, telescoping pole pruning saw

hand saw with changeable blade

UT OF D

ATE.

: u/cata

log

O ion .ed

Figure 6.—Common pruning equipment.

Shears

New Zealand typewith by-pass head

garden varietyby-pass head

hand pruner ratchet type with anvil head

German typewith anvil head

THIS P

UBLICATIO

N IS

For mos

t curr

ent in

format

http:/

/exten

sion.o

regon

state

10

T

OD g

What about Tools?Many different tools will work,

and different ones work well atdifferent tree heights. Criteria forselecting good pruning tools includethe following:• Cost

• Labor requirements and availability

• Physical ability of operators

• Quality of branch cut

• Likelihood of injury to tree bole/cambiumA chain saw, short-handled

pruning saw, or loppers works wellnear the base of the tree. Safetydictates using the chain saw up toonly shoulder height. Using chainsaws also requires more safetyequipment, including protectivechaps, heavy boots, gloves, andhardhat with eye and ear protectors.

Mini-chain saws mounted on longhandles also are available. They workwell on large branches (over 2 inchesat heights up to 12 or 18 feet, butsmaller branches are easier to prunewith hand saws.

Never bang conifer branches offwith a club, because the branchesoften break off beneath the bark, andmassive pitching results or long stubsare left. Dead hardwood branchesgenerally break off cleanly.

Short-handled pruning sawswork well up to about 8 feet. Along-handled pruning saw works up toabout 18 feet.

Hand-powered loppers or shearsmay be used on branches near thebase and up to 8 feet. Be sure topurchase heavy-duty loppers so theyare capable of cutting the largerbranches at the base of the tree.Hydraulic or pneumatic shears onlong, telescoping poles are becomingmore readily available.

Mechanical “tree monkeys”capable of climbing up to 35 or40 feet are available from a fewcompanies, but all have been reportedto have significant operationalproblems. Irregularities in trees suchas sucker branches, forks, or largebranch collars give tree monkeysproblems. It takes large-scale pruningoperations to pay for the initialinvestment.

HIS P

UBLICAT

For mos

t curr

http:/

/exten

Climbing trees with ladders also isa common practice for pruning up to20 feet. In New Zealand, wherepruning is done on a very large scale,hand loppers and ladders are used toprune up to 6 meters (20 feet).Loppers are favored because they cutcleanly and closely without injuringthe collar or bark. Hand pruners aregood for removing small brancheslow on the tree.

How much equipment you buydepends on your ambition, size ofstand, and how much money you arewilling to spend. Figure 6 displayssome of the more common pruningequipment.

Caution! Be careful with sharptools to avoid injuring yourself orthe tree!

)

Long-termConsiderations

Record keeping is important,especially for pruned stands. Pruningis an investment in the future valueof your trees and timber stand.Therefore, carefully document andfile the location of all pruned stands(and trees) on maps in your man-agement plan. Permanent tags onpruned trees can help you keep track,or serve as a reminder to yoursuccessor.

You should keep the followingrecords:• Stand location

• Number of trees per acre

• Species

• Dbh of tree at the time of pruning

• Height of pruned log, including allliftsSelling pruned trees most likely

will be different than selling low-quality sawlogs. Because of theirvalue, you will want to separate thepruned logs from others and be able tverify how much clear wood actuallyexists on each pruned log. This willensure you get top dollar from logbuyers. You can do this if you keepaccurate records.

Of course, you should have logbuyers examine the pruned trees andprovide you with bids before youactually cut them. To get the highest

ION IS

OUT

ent in

formati

on

sion.o

regon

sta

11

value when selling logs, always getthree or more bids and target thosethat manufacture clear-wood productseven if they are located at consider-able distance.

Harvest operations in prunedstands demand special attention. Takecare to buck trees into pruned andunpruned logs. If you leave unprunedportions attached to pruned portionsof the log, the whole log may sell atunpruned value. Careful sorting ofpruned and unpruned logs and closesupervision of loading will ensure thatall pruned logs are sold together formaximum value.

ATE.

Is there cost-shareassistance for pruning?

Cost-share assistance for pruning isavailable to nonindustrial privatelandowners through the StewardshipIncentive Program. Cost-share ratesare determined by the State SIPcommittee. Actual cost-share amountsand availability may vary from onecounty to another and from one stateto another. For more information,contact your local State Departmentof Forestry or Consolidated FarmService Agency (formerly AgricultureStabilization and ConservationService) office.

F

:

te.ed

u/cata

lo

o

SummaryPruning selected trees in your

forest stands can be a good invest-ment, assuming future markets reflectpresent conditions. Many owners likethe appearance of a pruned stand, butit really doesn’t make good economicsense to prune all trees in a youngstand. Instead, prune the final croptrees in stands you plan to manageintensively for several decades.

Prune in one to three lifts so thatyou can prune the bole before it growsover 4 to 8 inches in diameter.Always leave at least 50 percent ofthe total height of the tree in livecrown. This minimizes height anddiameter growth loss. Be careful withsharp tools to avoid injury to yourselfand to the bole of the tree. Finally,keep good records so that you and/oryour successor can market the valueproduced with all that hard work.

n

g

For MoreInformationThe following publications areavailable from:

Publications OrdersAgricultural CommunicationsOregon State UniversityAdministrative Services A422Corvallis, OR 97331-2119(503) 737-2513Fax: (503) 737-0817

We offer discounts on orders of 100 ormore copies of a single title. Pleasecall for price quotes.

C

Managing Hardwood Stands forTimber Production, EC 1183, byDavid Hibbs (Oregon State Univer-sity, Corvallis, reprinted 1993). $1.50

Agro-forestry: Growing Trees,Forage, and Livestock Together,EC 1114, by Robert Logan (OregonState University, Corvallis, reprinted1993). $1.00

12

ATION IS

OUT

t infor

mati

egon

Thinning: An Important TimberManagement Tool, PNW 184, byWilliam Emmingham and NormanElwood (Oregon State University,Corvallis, reprinted 1992). $1.00

Thinning Systems for Western OregoDouglas-fir Stands: What Is Best forYou?, EC 1132, by WilliamEmmingham and Daniel Green(Oregon State University, Corvallis,reprinted 1993). $1.00

Using Precommercial Thinning toEnhance Woodland Productivity,EC 1189, by Paul Oester and WilliamEmmingham (Oregon State Univer-sity, Corvallis, reprinted 1992). $1.25F D

ATE.

lo

O

on:

state.

edu/c

ata

The Woodland Workbook is a collection of publications prepared by the Oregon StateUniversity Extension Service specifically for owners and managers of private, nonindus-trial woodlands. The Workbook is organized into separate sections, containing informa-tion of long-range and day-to-day value for anyone interested in wise management,conservation, and use of woodland properties. It’s available in a 3-ring binder withtabbed dividers for each section.

For information about how to order, and for a current list of titles and prices, inquire atthe office of the OSU Extension Service that serves your county.

Extension Service, Oregon State University, Corvallis, Lyla Houglum, interim director.This publication was produced and distributed in furtherance of the Acts of Congress ofMay 8 and June 30, 1914. Extension work is a cooperative program of Oregon StateUniversity, the U.S. Department of Agriculture, and Oregon counties.

Oregon State University Extension Service offers educational programs, activities, andmaterials—without regard to race, color, religion, sex, sexual orientation, nationalorigin, age, marital status, disability, and disabled veteran or Vietnam-era veteranstatus—as required by Title VI of the Civil Rights Act of 1964, Title IX of the EducationAmendments of 1972, and Section 504 of the Rehabilitation Act of 1973. Oregon StateUniversity Extension Service is an Equal Opportunity Employer.

THIS P

UBLI

For mos

t curr

en

http:/

/exten

sion.o

r