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JayDee  GunnellAssociate  Professor

Utah  State  University  Extension

Pruning  LandscapeTrees  and  Shrubs

What  to  use…

Hand  pruners• ½  -­‐ 1”  branches

Loppers• 1  -­‐1  ½”  branches

Pruning  saws• 2”  (and  up)  branches  

Types  of  pruners…

Bypass  type• cuts  much  like  scissors• cuts  are  smoother• easier  for  plants  to  seal  the  wound

Anvil  type• blade  presses  against  a  flattened  area• tissue  is  crushed  more  than  cut• difficult  to  make  clean  cuts

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When  to  prune…  Generally  speaking

During  the  dormant  season• easily  see  the  structure  

Any  month  that  doesn’t  end  in  “r”(September,  October,  November,  December)

Shrubs  that  bloom  early  spring• after  they  bloom

Roses• in  April  once  buds  have  swollen

Pruning  does  NOT stop  growth!

Pruning  …• Encourages  new  growth• Redirects  energy  into  remaining  branches  /  buds• Increases  flowering  /  fruiting• Can  be  like  a  bad  haircut…  it  will  grow  back•Worse  thing  to  do  is  nothing

Why  prune…

No  -­‐ Keep  plants  smaller?

Yes  – Start  with  the  easy  cuts…• dead• diseased• rubbing  or  competing•weak  angles  (less  than  45  degrees)• suckers  •water  sprouts

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Two  Basic  Pruning  Cuts…

Heading  cuts• Shortening  a  branch  or  shoot• Encourages  lateral  growth• Cut  above  bud  in  the  right  direction• Example:  shearing,  topping

Thinning  cuts• Removing  entire  branch  or  shoot  to  a  lateral• Re-­‐directs  growth• Opens  up  the  canopy  for  more  light

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Lateral  bud

Terminal  bud

Heading  vs  Thinning  Cuts

Extreme  Heading  Cuts

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Extreme  Thinning  Cut

Natural  Targets  to  Look  For…

Branch  Collar

Branch  Bark  Ridge

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Pruning  Callus  Wood  (Doughnuts)  

Cutting  Large  Branches…  Easy  as  1,2,3

1. Make  an  under  cut  (insurance  against  tearing)  

2. Rough  cut  to  remove  majority  of  the  weight

3. Final  cut  just  on  the  outside  of  the  branch  bark  ridge  and  collar

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Pruning  Large  Shrubs  – Renewal  Cuts

•Mostly  flower  on  1  year  old  wood• Remove  oldest  canes• Encourages  new  growth• Encourages  flowering• Reduces  height  without  shearing

• Examples:• Lilacs,  forsythia,  viburnum,  dogwood,  mock  orange

Pruning  Smaller  Shrubs• Flowers  on  current  growth• Shear  to  shape• Encourages  new  growth• Encourages  flowering

• Examples:• Spirea,  potentilla,  bluemist shrub,  butterfly  bush,  barberry,  Russian  sage

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Pruning  Evergreens

Plant  the  right  one  to  begin  with!

• Not  tolerant  of  heavy  pruning:• spruce,  pine,  fir,  cedar

• Tolerant  of  shearing:• Juniper,  arborvitae,  boxwood  and  euonymus  

Pruning  Roses  – Hybrid  T  &  Floribunda

•mid  April  after  bud  swell• Produce  flowers  on  new  growth• Open  vase• leave  3-­‐5  canes  • cut  to  outfacing  buds• 12-­‐24  inches  tall

• Seal  cuts  against  insects

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Deadheading  Roses…

• Removing  spent  blossoms• Cut  to  first  5  leaflet• Most  will  re-­bloom  lightly  in  the  fall

Pruning  Roses  – Climbers

• Produce  flowers  on  1  year  old  canes• Prune  to  fit  trellis• Most  will  re-­‐bloom• leave  4-­‐6  buds  per  lateral

• Only  leave  canes  for  3  years• Remove  all  older  canes

Pruning  Wisteria

• Flower  clusters  formed  on  1  year  old  canes

• Summer  pruning• Shorten  vines  4-­6  buds• About  ½  the  new  growth

• Dormant  pruning• Shorten  vines  to  2-­3  buds• Flowers  born  on  short  spurs

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The  Take  Home  Message…

•Pruning  does  NOT  stop  growth•Pruning  directs  growth• Start  with  the  easy  cuts•Doing  nothing  is  the  worse  option