I have a typical urban lot so it isn't terribly large overall, plus it's all broken up into many small beds by various pathways and hardscape. I grow only a few hydrangeas as water is non-existent and expensive in the summer here in coastal Northern CA. OTOH, I just picked the last 'Sun Goddess' and 'Endless Summer' hydrangeas, along with a lone calla lily (they're just starting to bloom) and a 'Delany Sisters' rose that escaped the recent winter rains. I really like how the hydrangeas start to shade to green as they age; it adds an unexpected color to the vase.
gemini_sage, I group the moisture lovers together and water everything on soaker hoses. We have very bad adobe clay soil here, so when installing the garden we had the first 6-8" dug out and top quality compost put in. The compost is gradually being used up, but yearly mulching helps conserve moisture and provide nutrients. Our temps are very moderate in summer, so a deep soak every 2-3 weeks is sufficient.
It's hard to grow acid loving plants in Southern CA because the water is very alkaline. Plus, a lot of gardeners forget that the native soil is also quite poor and without enrichment, plants like hydrangeas, pieris, and azaleas/rhodies just won't do well, even near the coast where temps are more moderate. These plants can do well in coastal CA north or south but they do need more attention to siting and feeding/watering requirements than many of the other plants that are 'standards' out here. CA is high desert country.
It isn't that difficult to grow Hydrangeas, Azaleas and other acid loving plants in So. Calif., especially in the coastal environs and even the San Fernando and Simi Valleys.
Mophead hydrangeas thrive here if given protection from afternoon summer heat.
Not every area of So. Cal. has difficult clay soil, (although many do), but it can be easily ammended to grow azaleas, camellias, hydrangeas, etc. if very coarse ammendment is added and maintained.
All my hydrangeas and azaleas are planted in solid peat moss and they do extremely well. The acidity of the soil remains constant that way, even though our water is alkaline.
Many areas of So. Cal. are old former riverbed areas with ideal soil for growing many acid loving plants.
I found it in the Jung Seeds & Plants catalog that I just got in the mail. I am going to send for one. Cost $19.95 plus shipping. It says it is a 2 year old plant that is 12 - 15 inches and will be shiped bareroot.