Landscape Management Short Course Pruning Trees and Shrubs ... file2/22/2017 1 Landscape Management Short Course Pruning Trees and Shrubs -Principles and Practices Anthony Witcher

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Landscape Management

Short Course

Pruning Trees and Shrubs

-Principles and Practices Anthony Witcher Assistant Professor (Nursery Production and Sustainability) Otis L. Floyd Nursery Research Center

Minor Changes Made by M. Mote

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Some inexperienced people

may be reluctant to prune Don’t worry, it’ll usually grow

back (like a bad haircut)

Pay attention to the basics

So…why do we prune?

Strengthen the gene pool

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Reasons for Pruning

Remove dead, diseased, wounded limbs

Improve form and shape of a plant

Guide growth habit of a plant

Stimulate new growth

Rejuvenate older plantings

Bud Position

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Bud Arrangement

Tools of the Trade

Hand Pruners

• Anvil & Bypass

Up to 1/2”

Loppers

Hedge Shears

• Manual & Powered

Pruning Saws

Pole Saw

Chainsaw

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Tools of the Trade

Hand Pruners

• Anvil & Bypass

Loppers

• Up to 1.5”

Hedge Shears

• Manual & Powered

Pruning Saws

Pole Saw

Chainsaw

Tools of the Trade

Hand Pruners

• Anvil & Bypass

Loppers

Hedge Shears

• Manual & Powered

• Only for hedging

Pruning Saws

Pole Saw

Chainsaw

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Tools of the Trade

Hand Pruners

• Anvil & Bypass

Loppers

Hedge Shears

• Manual & Powered

Pruning Saws

• 1.5”+

Pole Saw

Chainsaw

Tools of the Trade

Hand Pruners

• Anvil & Bypass

Loppers

Hedge Shears

• Manual & Powered

Pruning Saws

Pole Saw

• Bypass blade and pruning saw

Chainsaw

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Tools of the Trade

Hand Pruners

• Anvil & Bypass

Loppers

Hedge Shears

• Manual & Powered

Pruning Saws

Pole Saw

Chainsaw

Tools of the Trade

Hand Pruners

• Anvil & Bypass

Loppers

Hedge Shears

• Manual & Powered

Pruning Saws

Pole Saw

Chainsaw

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Pruning Young Trees

At planting

• Dead/damaged branches

If these are present, you should find a better plant source!!

• Correct structural defects

Codominant stems

Shape/thin over time to prevent problems

Pruning Young Trees

At planting

• Dead/damaged branches

If these are present, you should find a better plant source!!

• Correct structural defects

Codominant stems

Shape/thin over time to prevent problems

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Pruning Established Trees

Priorities to Consider

• Removal of dead/dying branches

• Clearance for pedestrians or vehicles

• Relieve weight-stressed branches

Prevents injuries and property damage

• Hire a Certified Arborist for large trees

Pruning Established Trees

Crown Cleaning

• Selective removal of

dead, dying, diseased

or weak branches and

water sprouts.

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Pruning Established Trees

Crown Thinning

• Selective removal of healthy,

live branches to increase light

penetration and reduce weight.

Pruning Established Trees

Crown Raising

• Removal of

lower branches

for clearance of

obstacles,

traffic, and

pedestrians

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Pruning Established Trees

Crown Reduction

• Selective removal of

both living and

dead branches to

reduce tree height

or spread

• Do not remove

more than 1/3 of the

crown in a single

event

• If tree is too large for

area, best to cut

down and replant

with smaller tree

Pruning Large Branches

3-Cut Method

• For branches > 1.5” in diameter

• Remove outer branches to reduce

stress on this cut

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Pruning Smaller Branches

Cut back to bud, lateral

branch, or main trunk

Never leave a stub

If cutting to a bud, leave

enough stem to protect bud

Wound Healing

Wound dressing (paint, etc) is not recommended in

most pruning scenarios

A proper cut will heal properly naturally

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Topping – Don’t Do It!!

Topping – Don’t Do It!!

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Chainsaw Art

Crape Murder

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Natural Beauty

Proper Pruning – Crape Myrtle

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Pruning Shrubs

Thinning

• Reduces size of

plant

• Increases plant

density and

flowering potential

• Remove 1/3 of

branches to a

lateral branch or

main trunk

Pruning Shrubs

Rejuvenating/Renewal

• For severely overgrown plants

Azaleas, Chinese hollies, camellias, abelia, nandina

• Cut all branches 6 – 12” above ground

• Timing – Late winter

• Thin/shape new growth to maintain form and size

• NOT recommended for boxwoods or narrow leaf evergreens (juniper, arborvitae, pines, etc.)

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Pruning Shrubs

Shearing/Heading

Back

• Not recommended

• All new growth at outer

edge

• More prone to insect

and disease issues

Pruning Shrub Roses

Knockout, other shrub-

type varieties

• Mid February

• Remove dead/diseased

canes

• Cut back by 1/3 – 1/2 of

height

• Do NOT shear

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Hedge Pruning

Only recommended for formal

gardens

Allow hedges to develop

informal natural growth habit

• Much less work!!

• Can’t be achieved with poor plant

selection

Hedges

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Equipment Innovations

Timing of Pruning

Remove dead/damaged branches any time of year

Late winter ideal for most plants

Delay until newly emerge leaves are hardened off

Late summer and fall pruning may encourage new growth vulnerable to cold damage

Trees

• Late winter is ideal; but mid-summer works too

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Timing of Pruning

Broadleaf Evergreen Shrubs

• Camellia, hollies, boxwood

• Require very little pruning

• Late winter

Narrow Leaf Evergreens

• Junipers, spruce, fir, arborvitae,

cryptomeria

• Late winter/early spring before

growth begins

• Never prune into old wood behind

foliage

Timing of Pruning

Flowering Trees & Shrubs

• Spring flowering (Before July 1)

Bloom on previous season’s growth

Azalea, forsythia, spirea, lilac

Immediately following flowering

• Summer/Fall Flowering

Bloom on current season’s growth

Crape myrtle, abelia, vitex, butterfly bush

Dormant season (late winter)

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Timing of Pruning

Flowering Trees & Shrubs

• Spring flowering (Before July 1)

Bloom on previous season’s growth

Azalea, forsythia, spirea, lilac

Immediately following flowering

• Summer/Fall Flowering (After July 1)

Bloom on current season’s growth

Crape myrtle, abelia, vitex, butterfly bush

Dormant season (late winter)

Pruning for Disease

Management

Pruning helps:

Maintain air circulation

and sunlight penetration

into canopy

• Prevents disease

establishment

Reduce spread of spread

of pathogens from

infected branches

Limit new damage to

branches during storms

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Pruning for Disease

Management

Always sterilize pruning tools between cuts with household bleach (25% solution) or rubbing alcohol (50% solution)

Prune during dormant season to prevent spread

• Wounds heal before environment is ideal for pathogens

• Insect vectors may be attracted to plant sap

Remove and Destroy all infected trimmings/leaves

Alternatives

• Plant resistant varieties

Pruning for Disease

Management

Specific Diseases – Some Hope

Fire blight (Pears, apples, etc.)

• Remove infected branches 10-

12” below visible symptoms

• Remove during dormant season

Black Knot (Plum, cherry, etc.)

• Remove infected branches at

least 4” below knot

• Remove during dormant season

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Pruning for Disease

Management

Specific Diseases – No Hope

Boxwood Blight

• After confirmation, remove and

destroy whole plant and all leaf

debris

Rose rosette

• After confirmation, remove and

destroy plant and adjoining

plants

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Thank You