Many hydrangeas only bloom on old wood, meaning that buds develop the year before. Thus if they were pruned at the wrong time then the buds were cut off. The other possibility is that the winter killed off the buds and thus you have no blooms. Did they come with any sort of tag giving you information on what hydrangea it could be?

As for the small blooms, it is because it is a young hydrangea. My first year ES also only flowers that large but my more mature ES (twice as big as your photo I would say) has multiple 6" blooms. Both are also in places that get no direct sunlight but are bright. One is right below a cherry tree and the biggest one is right below a pine tree. Your plant will mature to give you the blooms you want, just give it time.

Hydrangeas sold at grocery stores - like Trader Joe's - are manipulated into bloom at an early age and often, out of season. Once they have finished up with the flowers and buds they come with, they are done for that season.....and maybe even for a couple of seasons. They need time to establish in the garden and put on some maturity before they can be expected to flower again and to produce flowers of typical size. In zone 9/10, winterkill of buds is not an issue but the previous comments about pruning times are relevant.

If you want a hydrangea expected to produce flowers consistantly and of "normal" size, purchase a plant intended for the landcape from a nursery or garden center. Grocery store hydrangeas, aka florist's hydrangeas, are intended as blooming houseplants or gift plants, although they can usually be transitioned into the garden well.....given time :-)

Hydrangeas in SoCal are an iffy proposition. Success is determined by where you live in SoCal,and which microclimate you have.

I suggest you consult with a large retail garden center close to your home -- not a big box store -- to determine if you have any chance of success.

Further, if it happens that your current hydrangeas are successful,the will soon outgrow their space and obscure the window.

Jean
who gardened in Long Beach, CA,for 30-some years
but who now lives in Portland, OR, where hydrangeas are easy peasy.

My experience with hydrangeas in coastal SoCal (Laguna Beach) is they grow just as well and as easily as they do here in the PNW. And they have an exceptionally long bloom season to boot :-)

Success is a matter of a suitable micro-climate. Seldom so in Long Beach.

Wonder where reesie lives.