I would think you could grow hydrangeas, because I've seen many on Cape Cod, but they have so many new, great varieties. Also, you can grow the vining one, lace caps, mop heads, and many more. Acid soil will make those beautiful blue blooms that we struggle for in Oklahoma. When I saw your post read "sandy, acid soil", I almost KNEW you were in Massachusetts. Also the azaleas come in such wonderful colors, too. But, it is a short bloom period for us, don't know about you. I would google "acid loving plants" and see what you come up with.

What a wonderful place to live - love the Cape.

Susan

Hi,I, too, live on the Cape and have sandy soil in very heavy shade. My shade is caused by maples, elms and pine. I have planted several varieties of hydrangas, summer sweet shrub, goat's beard, tirella, columbine, bleeding heart, spirea, astillbe, and of course hostas. Dig hole, place plant and fill with peat and a little of your sandy soil. Many of these plants prefer damp soil, but this garden is 3 years old and requires watering once a week for 1 1/2 hours.I would also suggest adding water retention pellets, found in all garden supply places. Good luck. trial and error is best method.