Everything you ever wanted to know about pruning trees, shrubs and perennials but was afraid to ask
EVERYTHING YOU EVER WANTED TO
KNOW ABOUT PRUNING…
BUT WERE AFRAID TO ASK
Basics for residential light tree, shrub and perennial
President Lowe’s Greenhouses
YOU’RE JUST A SNIP AWAY FROM PERFECTION!
Pruning is an art form that can’t be
simply communicated in a classroom
setting. It is a lifelong pursuit of
gathering a combination of plant
knowledge as well as gauging
cause/affect results from various
techniques, timing and ever-changing
#1 LIGHT TREE PRUNING
(AND YOUNG TREE TRAINING)
Pruning is not like Red Bull…
it does not give you wings!!!
The first thing to know is your plant’s tendencies. What
is its natural shape and growth rate? What are its
features and benefits.
What are we looking to do?
*Remove dead, damaged or diseased branches.
*Enhance tree structure and reduce risk of future branch
*Promote healthy and attractive growth.
*Enhance flowering and/or fruit production.
*Eliminate rubbing/competing branches.
*Remove co-dominate stems.
*Extend life of landscape plants.
You may end up finding this information most helpful
when selecting new tree specimens.
When is the time to prune?
What is the desired effect?
*Maximize growth: in early spring.
*Minimize risk of pest and decay: during
*Minimize effect on fruit/flowers:
immediately after flowering.
***Timing may not be an option when
pruning storm damage or when
eliminating hazardous branches.
*Removing dead, broken or
*Selecting a dominate leader or
multiple strong leaders . (not all
trees have a central leader)
*Select the lowest permanent
*Select scaffold branches that
are spaced evenly both vertically
*Identify temporary branching
for energy production and
***Do not remove any more
than 25% of a tree canopy per
*Are forked branches of similar size lacking a normal
*Frequently forms a weak point of tree with included
bark. (Bark embedded in crotch of tree)
***Not all trees have a single dominant leader.
*Removing dead, diseased, rubbing, competing and broken
*Cleaning can be done at almost any time of wear.
*Removal of branches to improve light penetration and air
*Reduces risk of storm damage.
*Shows off trunk form and/or attractive bark.
*Be careful not to be too aggressive.
Much of the most important pruning on trees will be done
when they are very young so selection and training are very
important for a long and care-free life.
*Shrubs stand to gain the most from proper pruning techniques.
*Fast pruning is easy to learn, easy to do and easy to sell.
*Pruning is often done in late summer when it is convenient for
landscape companies. (A perfect time to cut off newly formed flower
*Proper pruning takes time, patience, knowledge and (when done
correctly) is not easily detected.
Remember…good pruning cannot
make up for bad design!!!
PRUNING LAWS, PRACTICES, PRINCIPALS AND…
*Pruning stimulates growth from the point of pruning.
*Shearing and pruning are not the same.
*Prune spring flowering shrubs immediately after flowering.
(Flower buds are formed during previous summer)
*Prune summer blooming shrubs during dormancy.
*Trimming can be done any time.
*Know what plants bloom on old growth and new growth.
*Know your plants. Consider getting professional assistance
to help identify your specific pruning needs.
How are your shrubs are like Olympic athletes?
You have to know what
kind of shape you’re in!
It is to your and the
plants benefit to
plant growth instead of
fighting against it.
Another very important
detail is to understand
your plants potential
A 40 year old landscape planting.
There is only 1 pruning method that is effective in this scenario!
DO PLANT TAGS LIE?
Now let’s look at some shrub pruning techniques.
THINNING OR GRADUAL RENEWAL PRUNING
Examples of common shrubs that benefit from gradual renewal or
Aronia, Clethra, Deutzia, Forsythia, Itea, Lilac, Mockorange,
Potentilla, Spirea, Viburnum, Weigelia.
NOT SO GRADUAL RENEWAL PRUNING
Shrubs that generally respond well to complete renewal pruning:
Aronia, Clethra, Cornus (shrub forms), Deutzia, Forsythia, Hydrangea
paniculata, Itea, Mockorange, Potentilla, Privet, Spirea, Taxus,
Common shrubs that are often sheared:
Azalea, Barberry, Boxwood, Burning Bush,
Forsythia, Hibiscus, Lilac (Dwarf), Privet, Taxus.
Sheared plants need
to be periodically
thinned to allow
light to penetrate
the outer shell of
As a rule, shear
(*Ideally done in
late fall to allow
AND FINALLY… THE MOST FRQUENTLY
ASKED QUESTION ABOUT PRUNING IS:
Hydrangea paniculata (Cone shaped, summer flowers)
Easy to bloom, hard renewal prune in dormancy.
*Trimming a 2nd time in early summer can also be
helpful in certain situations.
*Certain cultivars respond better to mid-season
Oak Leaf Hydrangea quercifolia (Large leaves, summer bloom)
Thin as needed or prune hard to renew.
Hydrangea macrophylla (Big leaf Hydrangea)
Some bloom on old wood, others on new so it is important
for you to know what you have and prune accordingly.
When in doubt, do not cut all the way down and protect
stems from freeze and frost.
Snowball Hydrangea arborescens
(Soft leaves, round flowers in summer)
For best results, complete renewal pruning every year.
WHY IS PERENNIAL PRUNING
*MORE COLOR BOTH IN FLOWERS AND FOLIAGE.
*EFFECTIVE AND ORGANIC INSECT AND DISEASE
*IMPROVES OVERALL GARDEN APPEARANCE.
*SAVES WORK AND TIME IN THE GARDEN.
There are many pruning techniques to enhance perennial
Understanding some of the common terminology may be
WHAT IS DEADHEADING?
No, it has nothing to do with
Deadheading is the removal of
spent flowers to prolong bloom,
promote re-bloom , improve
aesthetics or to prevent seeding.
Bloom sequencing- Cutting back a plant to delay flowering.
Cutting back- Pruning back foliage and perhaps flower buds
and deadheads to renew a plant’s appearance and/or to
encourage new growth and flowering. Cutting back can also
be used to control eventual plant height and/or flowering
Pinching-Removing the growing tip and first set of leaves to
promote the development of side shoots. Used to promote
fuller, stockier plants perhaps.
Thinning- Removing shoots, leaves or stems to open the
plant canopy allowing for better air circulation
PERENNIALS THAT MAY REBLOOM
WITH PROPER PRUNING
Achillea, Aster frikarti ‘Monch’, Astrantia, Campanula,
Coreopsis, Delphinium, Dianthus, Dicentra formosa,
Digitalis, Echinacea, Echinops, Gallardia, Gaura, Geum,
Helenum, Heliopsis, Penstemon, Phlox maculata,
Platycodon, Nepeta, Salvia nemorosa, Scabiosa,
Stokesia, Tradescantia, Viola.
Be sure to select cultivars that readily re-bloom.
MAY-JUNE ZENITH OF BLOOM
JULY GETTING TIRED
‘May Night’ are better
PERENNIALS TO PRUNE FOR IMPROVED
Achillea, Alcea, Alchemilla, Anemone, Arabis, Armeria,
Artemesia, Aruncus, Bergenia, Brunnera, Campanula,
Chrysogonum, Coreopsis, Delphinium, Dianthus, Dicentra,
Echinacea, Echinops, Geranium, Helenum, Heliopsis,
Helleborus, Hemerocallis, Heuchera, Hosta, Iris (bearded),
Kniphofia, Leucanthemum, Monarda, Nepeta, Peony,
Penstemon, Phlox, Physostegia, Polemonium, Pulmonaria,
Salvia, Scabiosa, Stachys, Tradescantia, Veronica, Viola.
When in doubt… if it looks bad cut it off!