Alexander Pensky wrote:

Phisherman 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.

Hydrangea macrophyllas will bloom from the growth that was generated the previous year, aka old wood.
Consistantly pruning back 18-24 inches may very well remove any of that previous year's growth, therefore
resulting in no flowers. Provided your climate is suitable, pruning off the dried flower heads and just back to
the first or second set of buds is usually sufficient to assure a tidy plant AND flowers. More extensive pruning
can be done to control size - typically it is recommended that older, very woody canes be removed to encourage
new, more vigorous growth and this will help to keep the plant in size check. Or, you can go ahead and cut back
long leggy stems with the understanding that they will not produce flowers that season. I usually do this in
March in my area, when the new buds are quite visible. There is also the option of not pruning at all, other than
to remove obviously dead wood and old, winter-ratty flowerheads. I tend towards this practice 80% of the time,
allowing the shrub to grow unchecked.

Generally, lack of flowering with hydrangeas is due to either incorrect pruning methods or winter cold which
damages the dormant flower buds and/or causes dieback of the last season's growth.

pam - gardengal