In article , Alexander Pensky
wrote:
Mine did not bloom this year either. It doubled in size from last
year and it is now over 4-feet across and 3 feet high. I plan to
protect the plant by piling leaves on top of it before the winter cold
arrives. The blooming mechanism is on last year growth, so if that
freezes or is pruned there will be no flowering. It is a beautiful
lush green plant, even without flowers.
Can someone who is a hydrangea expert clarify this for me? I have the
same problem with mine. I know that winter kill is the problem, but I
think the "buds" that get winter-killed are not the flower buds (as they
would be with a lilac e.g.) They are buds which will form new branches
the next year, and these branches will then form flower buds during the
summer. Either way I'd have to prevent freezing, but it does make a
difference in the pruning method.
So, when pruning a mop-head hydrangea macrophylla, do I:
(1) cut off the faded flowers but leave all the new buds intact, since
those are all my next year's flowers, assuming they don't freeze... or
(2) cut all the old stems right back to 18-24", or to the point where I
want the new growth to start next year; don't worry about cutting off
some buds, because the flower buds haven't formed yet ????
I've tried researching this in gardening books and they all say
different things.
- Alex
Pruning for shape can be done in autumn after the shrub ceases to bloom.
But for best bloom, pruning is done in late winter or early spring, when
buds are most evident, & the buds define where pruning cuts are made.
As a generality, if you have kept the dried flowerheads on the branches
until winter's end, just before spring trim the flower stems back to the
first fat pair of buds. You can also underlimb a bit if it's a Bigleaf
cultivar that flops to the ground with rangy bottom limbs, as any flowers
produced down there will just lay on the ground, & blooms will be
bigger if encouraged mainly on the upright growth. Letting it go all wild
might get more flowers, but they'll be smaller flowers that wear out
faster. A bit of trimming, even if it costs a few buds, encourages huge
flowers, & some cultivars will be inspired to bloom from July to as late
as November without interuption (more commonly July to October or
September).
Why a shrub wouldn't bloom is a hard call. Stress factors would include:
too much shade (they like partial shade); too little moisture (older
shrubs are very drought-hardy & the leaves could look quite nice, but
still not energentic enough to set buds); too wet from clayey soil;
depleted soil (heavy bloomers require a lot of feeding, certainly nothing
less than an azalea fertilizer in spring, but perhaps something stronger,
plus a couple times through the year); or a late-occurring freeze killing
buds just as they started swelling. I'm also of the opinion that tinkering
with pH levels to turn flowers bright pink stresses the shrub, which
really prefers acidic soil, & no shrub likes its pH levels changing
radically from month to month.
-paghat the ratgirl
--
"Of what are you afraid, my child?" inquired the kindly teacher.
"Oh, sir! The flowers, they are wild," replied the timid creature.
-from Peter Newell's "Wild Flowers"
See the Garden of Paghat the Ratgirl:
http://www.paghat.com/