Hello, roselo. Soil with lots of organic matter like compost will work well when planting hydrangeas. You can mix your soil with those 2 cubic feet organic compost bags (available at most nurseries, large & small). If your soil is mostly sandy, I would try to mix at least ratio 50/50. You can also grow them in pots as well. The planting or potting location should provide shade by 11am or so as the leaves will not hold up to the summer sun in the Summer months. The location should not be breezy as this may tend to wilt the leaves, especially on year one when the shrub is suffering thru transplant shock.

H. macrophyllas should do well and is probably available in many plances. Since your growing zone is long as mine, you may want to plant some of the reblooming varities (thin the Endless Summer Series, the Forever & Ever Series, etc). The grocery store plants tend to have problems with cold in zones 6 or colder but that should not be an issue for you. However, I rarely see rebloomers for sale at grocery stores.

Remember that when the summer months arrive, you will need to monitor the soil moisture. Over here in Texas, I begin to check that by May, when temps begin to reach into the 90s. In soil that is sandy, water usage can be 50% higher than normal so maybe 1.5 to 2 gallons of water will be needed each time you water. That is another reason for adding compost to the soil. Compost absorbs lots of water and, if you maintain 3-4" of mulch year around, that should help you a lot.

We had a very nice hydrangea representative in Orlando but she has been missing in action for a while. She preferred to plant hydrangeas in pots so she could easily move the shrubs if she needed to. But make sure the shrubs do not get too large when growing in pots. I would think a six footer would not do well in a pot unless you prune it now and then. But, that is another story.

Luis