Too big and very old hydrangea going out of control..help

[carosanto]

HI Y'all

I have a very big and very wide, er I'd say 7+ feet tall and 9+ feet spread, which is swamping my garden.  I've only been here a year, and in the winter I pruned it, but OMG did something wrong because it now has a lot of bare sticks showing, although loads of foliage too and plenty of flowers to come.

It reaches out over my garden, swamping things, and although beautiful in flower, a true blue, it must be tamed.  I don't want to mess with it right now as it is about to flower, but come the winter can I cut this very big, and very old (possibly 20 years or more) plant to the ground or will this kill it?   Love it but just want it in a smaller form so I can plan my garden round it.

Thanks in advance.

Caro

[carosanto]

[johhnyco15]

To get bigger flowers, cut them all the way back. In late winter or early spring, these shrubs can be cut all the way back to the ground. Smooth hydrangeas will produce much larger blooms if pruned hard like this each year, but many gardeners opt for smaller blooms on sturdier stems. hope this helps

[Obelixx]

I think when you should prune depends on what kind it is.   The paniculatas with the pointier, cone shaped flower heads bloom on new season's wood so can be pruned hard in late winter/early spring, given a feed and then left to get on with it.

The mopheads and lace caps flower on last season's wood and, as yours are blue, I suspect that's what you have.  I suggest you cut out all the brown sticks which are dead.  Then take out one third to a half of the remaining stems cutting them back to the first or second set of leaves from the base.   With the remaining stems, just remove the dead flower heads when done.   Next year, cut out another one third to a half of the longest stems at the beginning of spring.   Repeat the following spring as necessary.   

This regime will let you re-shape your shrub whilst retaining flower power.   However, if you're impatient to reduce its size clean it up now and you may get some flowering stems produced in time for next year.   Otherwise you'll just have to miss a season.