Pruning basics - Winter · PDF fileAlthough pruning can be done anytime during dormancy (late...

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Transcript of Pruning basics - Winter · PDF fileAlthough pruning can be done anytime during dormancy (late...

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    Pruning Shrubs Pruning basics

    What to prune 1. Remove dead wood, crossing branches, down-

    ward branches, watersprouts

    2. Remove old unproductive wood

    3. Create more air, light and space in the center

    4. Shape and size

    Where to cut and how

    Type of cuts

    1. Thinning (cutting back to side branches, thins out as it doesnt stimulate side


    2. Heading back (cutting back to buds or between buds, promotes side branching and a

    denser plant)

    3. Gradual rejuvenation (removal of 1/3 of oldest stems to the ground each year)

    4. Complete rejuvenation (cutting back all branches to the ground)

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    When to prune ; This depends on whether the shrub flowers on new growth from this year or on old

    growth from the previous year!

    1.Shrubs flowering on previous years growth generally flower before the end of June

    and should be pruned immediately after flowering thus giving time for new buds to develop

    Amelanchier (Serviceberry) Genista

    Aronia (Chokeberry) Lilac (Syringa)

    Azalea (Rhododendron) Mockorange (Philadephus)

    Early flowering Spiraea (Bridal Wreath) Magnolia

    Flowering Plum (Prunus triloba) May Day Tree (Prunus padus)

    Flowering Cherry (Prunus tomentosa) Viburnums

    Forsythia Weigela

    Privet Wisteria

    2.Shrubs flowering on this years growth generally flower after the end of June and

    should be pruned in the early spring before growth starts

    Annabella Hydrangea Summer flowering spiraea (mostly pink varieties)

    Hypericum Snowberry (Symphoricarpos)

    Hydrangea (Paniculata) Summersweet (Clethra)

    Roses Potentilla


    3.Shrubs grown primarily for their foliage and fruit rather than showy flowers should be

    pruned in the spring before growth starts

    Alpine currant (Ribes) Euonymus

    Barberry (Berberis) Ninebark (Physocarpus)

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    Blueberry (Vaccinum) Smokebush (Cotinus)

    Dogwood (Cornus) Sumac (Rhus)

    Elderberry(Sambucus) Winterberry (Ilex)

    Although pruning can be done anytime during dormancy (late fall - early spring when temperatures

    are above 20F) The open wounds from late fall and winter pruning might result in some winter

    damage and die back, so early spring is better. Shrubs flowering on previous years growth will

    have fewer flowers if pruned at this time as these flower buds will be pruned out, so after flowering

    is better in this case.

    If in doubt about what to prune in general just remove some of the oldest stems at the ground. Trim

    back any over -long stems to a side branch and remove any spindly weak growth.

    Pruning Chart

    Pruning chart

    Name When to prune How to prune

    Berberis (Barberry) Early spring Actually flowers on old growth but flowers are insignificant and is therefore

    pruned in the spring. Generally little pruning needed. Cut back some of oldest

    branches to the ground each year. Overgrown plants can be cut back entirely to

    ground level to rejuvenate.

    Used as hedges where it can be sheared.

    Blueberry Vaccinium Early spring After planting for the first 2-3 years remove fruit buds by cutting off the tips

    (2-3) of previous years growth (early fruiting stunts plants). Subsequent years

    remove low growing branches and any weak spindly growth. Head back

    overlong branches to 4-6 below top of bush. As plants reach about 5 years of

    age remove a few of the oldest canes each year.

    Clethra (Summersweet) Early spring Flowers on new growth. Cut back any overly long stems, periodically remove

    a few of the oldest stems at the ground.

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    Cornus (Dogwood)


    Pagoda dogwood

    Shrub-tree form

    Early Spring before

    bud break

    After flowering

    Since new growth has the most vibrant color, cut back older stems to the

    ground each year. Long whips should be headed back to encourage branching.

    Flowers on previous years growth. Little pruning needed, Shape as shrub form

    or single or multi stemmed tree. Lower limbs are removed to convert a shrub

    into a tree.

    Diervilla (Honeysuckle) Early spring Cut back oldest twiggy stems to ground every 3-4 years

    Euonymus (Burning


    Early spring Usually doesnt need any pruning. But if it has become too big which is often

    the case it can be completely cut back to 1-3. They can also be sheared, often

    to a globe shape or as hedges

    Forsythia After flowering.

    Pruning too late

    will remove next

    years flower buds

    Flowers on previous years growth. Dont prune for several years after

    planting. Cut up to 1/3 of old growth to the ground to stimulate new branch

    growth. Pinch off tips of new shoots when they are 1 2 long and head back

    long whips by 1/3 to stimulate branching and to increase next years flowers.

    To renew an old neglected plant cut back to 6-12 , old woody stems should be

    cut to ground level.

    Hamamelis (Witch


    Late fall after


    Little pruning needed. Thin out old stems of interior if it becomes crowed.

    Hydrangea arborescens -

    Annabelle etc

    Early spring before

    bud break

    Flowers on this years growth. The dry flowers add winter attraction so spring

    pruning is often preferred. Cut all branches to the lowest pair of strong buds

    which can be anything from 6-18 inches from the ground. The closer you cut

    to the ground the larger the blooms will be, but less sturdy stems, hence a

    floppy shrub.

    Hydrangea paniculata

    Peegee etc

    Early spring before

    bud break

    Flowers on this years growth. Do not cut back as hard as arborescens

    varieties, but establish a woody framework anything from 10 36 tall, prune

    back previous seasons stems to 2-4 strong buds. Only paniculatas can be

    pruned to tree forms by letting one vigorous stem grow upward, cutting it off

    at required height and after branches have developed cutting them back to 4

    buds. Thereafter prune the top as you would a shrub. Cutting off at the ground

    level will revert back to shrub form.

    Hydrangea macrophylla

    Twist-n-shout etc.

    For Wisconsin


    Late summer after


    Early spring

    Flowers on new and previous years wood. Cut back dead flower heads to a

    strong pair of buds or new shoots. On older bushes, cut out some of the thin,

    weak or old wood to the ground to keep the shrub vigorous.

    For zone 4 it dies back so should be treated like annabella and cut back in




    After flowering Flowers on previous years wood. On younger plants, only cut vigorous stems

    that have flowered to strong side shoots. On mature plants, also cut out a few

    woody older branches that no longer bloom to ground level. Dont need to

    prune every year. Best when left to reach full size naturally. Can be completely

    cut down for renewal

    Physocarpus (Ninebark) Early spring Actually flowers on previous years wood but flowers are insignificant so

    prune in spring.. On mature plants, cut out older branches to the ground. Dont

    just cut part of the branch, as twiggy shoots will sprout from the end of the

    pruned branch.

    Potentilla Early spring Flowers on this years growth. Cut out a few of the older less flowering stems

    and shorten overlong stems each year in spring to renew vigor. Potentillas are

    more attractive with a loose open form so dont just shear them back at this

    time. After flowering, trim with shears to tidy up. Doesnt like to be

    completely cut back

    Raspberries-fall bearers or



    Late fall

    Late fall

    Bear fruit on new canes.Cut completely to the ground each year

    Bear fruit on previous years canes. The 2-year-old canes that have just finished

    bearing and are woody with light green-yellowish leaves should be cut to the

    ground. The new green canes with lush green foliage should be thinned out

    leaving the thickest canes 3-4 per foot of row, these will bear fruit the

    following year. In the spring head these canes back to 5 feet.

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    Late spring after


    Generally little pruning is needed. Dead heading flower clusters will encourage

    new growth. Pinching out slender terminal growth buds (not the fat flower

    buds) will promote branching. Long leggy branches can be cut back to an inch

    above a leaf whorl to encourage a more compact growth. Overgrown shrubs

    respond well to hard rejuvenation, but will take a few years to bloom again. To

    rejuvenate cut back main branches to staggered heights of around 6 best done

    during winter dormancy