When
it comes to the world of trees and shrubs, there exists, for those of us who
care, a god. His name is Michael Dirr.
A professor of horticulture at the University of Georgia, he has written
a book, Manual of Woody Landscape Plants: Their
Identification, Ornamental Characteristics, Culture and Propagation and Uses, (otherwise known as the bible) which is the most widely sold
reference book in the world of horticulture and landscape architecture. It has
sold over 250,000 copies, which is fairly impressive for a book with small
black and white pen and ink drawing of leaves.
I mention these credentials, because I love
being right, and Michael Dirr has confirmed that, once again, I am. I speak of
course, about not pruning hydrangea.
Why, you might ask, are you bringing up
hydrangea pruning now in the depths of this hideous weather? No one is really
playing outside in the garden anymore, are they? Well of course they are I
would reply with a snort if you asked me this question face to face, and I
bring this up now, because right now is when Michael Dirr is chatting via email
with a colleague at work. Imagine that. He’s emailing with god.
So
hopefully you all remember everything I’ve taught you previously about not
touching your hydrangeas until springtime. That you are allowed to deadhead
(remove the dead flowers) but that you really should not do any pruning until
spring time, and then, when it comes to the macrophyllas and serratas (the
mopheads and the lacecaps) you do not do any pruning at all, you just remove
dead wood. You actually don’t prune querifolia or petiolaris either (oakleaf or
climbing hydrangeas) but most people just plant the former two varieties and
that’s all they care about. So, since
you’ve been paying attention over the last few years, you therefore have not
whacked back your hydrangeas when you raked up your leaves. In fact, I’ve made
you so paranoid you won’t even make eye contact with any shrub that starts with
the letter H.
I’m
here to tell you what Michael Dirr wants you to do with your pruners. Nothing.
He too wants you to wait until spring. Even when it comes to your paniculatas, the
panicle types – Tardivas, Limelights, Pee Gees, etc. I know people who like to
prune these now, I’ve even been known to start to cut mine back in February,
when I’m bored, but folks god has spoken and he’s saying wait, and
recommending, “… a light removal of spent inflorescences.”
The
reason I feel, is of course, simple. As this past year demonstrated, we don’t
know whether stems are going to be alive or dead next spring, since none of us
can predict the winter. For most of us this past spring, all those stems of our
Endless Summers and Nikko Blues were toasted by the winter and new growth
wasn’t coming in on old wood, it was only emerging from the base or the crown
of the plant. That’s why most hydrangeas were not flowering; the only growth
was new growth and most hydrangeas bloom on old growth. Endless Summer is a
reblooming hydrangea, which means that it blooms on old wood as well as new
wood. All reblooming hydrangeas are also unusual in that they have flower buds
on 85% of the buds on old wood, so that even if the top buds on the old wood get
blasted by the cold, the bottom ones have a chance of flowering.
So
says Michael Dirr. He also says that his newest reblooming hydrangea, the one
called BloomstruckTM, is the best rebloomer to date and is, “… exceptionally stem hardy. Survived
50 days below zero with a low of -28 degrees in Bailey’s trial nursery area in
Minnesota.” He goes on to say that
while it was being tested in the same trial area it was killed to the ground,
but regrew the next spring and had flowers on every terminal by June. Nothing
like that happened here with our Endless Summers. Mine never even saw a flower
until September.
Which
brings us finally to the reason why I am writing about hydrangeas in the second
week of December. No I’m not crazy.
Yes,
you maybe should wrap your hydrangeas to protect them from the upcoming winter.
This
is not something I’m used to saying, but after last winter, I’m giving it a
strong thumbs up. There was only one gardener out here in the Hamptons that I
know of who had flowers on all the hydrangeas in all his gardens this year, and
that was a gentleman who used Wilt pruf on all his hydrangeas’ buds and then wrapped
each and every one of those Wilt prufed plants in all of his clients’ gardens
in burlap.
I’ll
be honest, I’m not going to do it in my garden because I don’t have the time to
do it, nor can I afford to pay someone to do it for me, but if I could, I
certainly would, and I’d like to recommend to you to do so.
Now
luckily for me, this year we’ve had a long, slow cool down. It’s not the sudden
drop we had last fall, followed by high temperatures and then a long, cold,
deep winter, so this year the plants have had a better chance to acclimate, but
we shall have to wait and see. It’s actually the abrupt up and downs, the days
that rocket down from high 40’s to low 60’s degree afternoons to low 30’s and
high 20’s at nights that do the most damage to plants.
And
I know that everyone keeps talking about how unusually cold this past winter
was, but when I was a kid Mecox Bay froze solid enough each winter for us to
ice boat across. An iceboat is a sailboat on enormous ice skates, so that meant
the bay was not just skinned with ice; it was deeply, solidly frozen.
I
also know that everyone had a more diverse garden when I was a kid, there were
weigelas and kolkwitzias and spireas and viburnums and hydrangeas. No one just
used a mass of hydrangeas to give them color and nothing else, so if it was
really cold and there were no hydrangea flowers there were other ways and means
to have color in your gardens. Of course this was when people were also doing
more with perennials, a phase that seems to have passed, but that’s all for
some other conversation. I actually don’t think it was that unusually of a cold
winter, I just think we all got lulled into thinking those incredibly hot summers
were the norm.
Don’t
you remember when we were kids? No one had air conditioning then, and we all
were fine with fans. Maybe there were 4 or 5 killer nights when you wanted to
sleep on the porch, because the house was too hot, but AC was not a fact of
life. So maybe last year was an anomaly, and this winter will be mild again and next
summer will be a scorcher. Or maybe not. I actually have no idea. Nor does
Michael Dirr. We asked his advice and he sent my colleague a presentation from
one of his associates, Mal Condon who owns Hydrangea Farm Nursery in Yarmouth
Port, MA.
He suggests
you wrap your hydrangeas.
Paige
Patterson was planning on buying a few more bulbs now that they are on sale,
but she’s coming down with a terrible cold.
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