Yes, all hydrangeas like acidic soil. They will tolerate some alkalinity but after a certain point, when the alkalinity gets high enough, the shrub will have difficulty absorbing iron from the soil via the roots and the leaves will develop signs of iron chlorosis: the normally dark green leaves become light green/bronze/yellow while the leaf veins remain dark green.

A soil test should also be done every 5-10 years so you can check how the soil is doing with regards to minerals like nitrogen, phosphorus, potassium, magnesium, calcium, etc. Since hydrangeas do not tend to respond to fertilizers like roses do (with lots and lots of growth), there is no need to apply extra fertilizers. As a matter of fact, if your existing fertilizer regimen is working and a soil test shows all is fine (no excessive or defficient amounts of minerals) then continue doing what you are doing.

Hydrangeas can be fertilized once a year in Spring using organic fertilizers like cottonseed meal, compost or composted manure. A 1/2 to 1 cup should be fine for a newly planted hydrangea. You can also use a general-purpose slow-release fertilizer like Osmocote 10-10-10 per label directions. You should also maintain 3-4" of organic mulch throughout the year. During the growing season, you can also add some "weak" fertilizers like coffee grounds, liquid seaweed and liquid fish.

Thanks, Luis, I appreciate the input.