TIME TO PRUNE NEW WOOD HYDRANGEAS
Yes, it's time to prune
new wood hydrangeas. Now that it is mid spring and your
hydrangeas are dormant or just beginning to leaf out, this is the time to get
those clippers out for some of them. When I say some, I mean those that bloom
on new wood, the growth they will put on in the current season. In the late
fall when they still have their leaves, wait until they are leafless and
have gone completely dormant before you cut them. You can also do this pruning in winter when they are fast asleep.
If you want to know about pruning other hydrangeas, see my prior pruning post. I cover pruning big leaf hydrangeas, mountain hydrangeas, oak leaf hydrangeas, and
climbing hydrangeas.
I am talking here about 2
species of hydrangeas: hydrangea arborescens (woodland or smooth), e.g., 'Annabelle',
Incrediball®, Invincibelle® Spirit, 'Haas' Halo', and White Dome®, and panicle hydrangeas (PG), e.g., Little
Quick Fire®, Pinky
Winky®, Vanilla Strawberry™,
Quick Fire®
and 'Limelight'.
Before you even start,
however, make sure you have the right tools including some kind of
disinfectant. You don't want to unknowingly spread disease as you move from
plant to plant. A simple spray of rubbing alcohol (70%) from the drugstore is
all you need to protect your plants
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| PRUNING TOOLS |
or your desired disinfectant of choice. Just make sure you do it.
Basic pruning rules apply
to all hydrangeas. Take care of the 3Ds: Dead, Diseased, and Damaged wood. It
has to go. Next remove any stems that are crossing and growing inward. Look at
this example of an inward growing branch of a hydrangea paniculata. It rubbed
all winter long and left a deep cut in both stems which now have to go. If not,
it will allow insects and disease easy entry into the plant.
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| WOUNDED STEM FROM RUBBING NEEDS TO BE CUT OFF |
Since the arborescens will
bloom first, let's work on them first. For strong stems, you would be wise not
to take them down too far, especially the mophead versions as rain will
saturate the flowers and make them droop . Your best bet is to cut the stems no
lower than 18". You could even go as high as 3-4 feet or just simply
deadhead the spent flowers. But if the stems have been bent from the weight of
heavy wet snow, cut them below the bend: you don't want to start the season
with a bent stem which will surely cause a floppy flower.
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| HYDRANGEA ARBORESCENS AFTER PRUNING |
Next prune the paniculatas. According to a study done at the Chicago Botanic Garden
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| PINKY WINKY®UNPRUNED |
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| PINKY WINKY®AFTER PRUNING |
If your panicle hydrangea
is on a standard (single trunk) and looks like a lollipop, cut to maintain that rounded
top shape. Eliminate all growth on the main trunk and suckers at the base. You can prune as much or as little as you want.
Once you have finished
pruning, take the time now to apply the appropriate fertilizer (NOT 10-10-10), check your irrigation if
you have that, and reapply the correct mulch for each species (NO volcanoes).
I can't emphasize enough
if you cut either of these 2 species in the fall when they still have their
leaves, you could be in trouble. Pruning them when they are about to go dormant
sends them the wrong message and potentially robs you of the following year's
flowers. Don't do it.
I cover pruning in detail
in my book, Success with Hydrangeas, A Gardener's Guide.
