Any time you add a new shrub or tree to the landscape, it needs to be planted in an area where it will have all it needs to thrive, including plenty of space to spread out.
How many times have you seen a yard with huge plantings covering the front of the house. Windows might be blocked or walkways overgrown so badly that it makes you wonder why on earth those big plants were put there. The simple answer is that the size of the plantings were not taken into consideration.
When you come home from the nursery, most likely you will be carrying a fairly small and manageable bush. It may be difficult to imagine that one day it will be 4 feet wide, but if that is what the tag says (or your research), then you must plan accordingly. Before you leave the plant stand, ask someone if you aren’t sure what you are buying. There is always the internet too.
No amount of trimming will help if your hydrangea shrub is too close to the house. The natural beauty will be hindered if it can’t grown the way it was meant to. In fact planting near a foundation is a bad idea anyway, so find a nice sunny spot in the yard to put your hydrangea and make sure that you have a hose that will reach it for those dry days.
There are many types of hydrangeas and for the most part you can plan on them growing at least 3-4 feet in all directions, but chick on the type you want to grow to be sure because some will grow much larger.