They come in almost every color you can 
imagine – pink, white, tea-stain, burgundy, or even the color purple. And many shades in between. Hydrangeas – the word comes from the Greek hydra for water, and angeion for vessel – on Martha’s Vineyard are especially bluish purple. They really sport the Island team colors. Turns out we have fairly acidic soil. When soil is acid, and contains aluminum, hydrangeas automatically come out blue or purple. The remarkable thing about them, though, is that you can change the color of the flowers on individual plants. If you want your blue Vineyard blooms even bluer, there are a couple of options. Old wives tales instruct you to bury a nail or even a copper penny near a hydrangea plant, but a more fail-safe way 
is to add aluminum sulfate to the soil around plants that are at least two years old. You can spread a solution of one tablespoon of aluminum sulfate per gallon of water throughout the growing season. Make sure plants are watered well before you do this, and pour the solution 
on carefully; too much can burn the roots.
   
Different people, of course, prefer different colors. “Pink and Pretty is beautiful,” says Don Brown of 
Vineyard Gardens in West Tisbury, “but I’d have to 
say Nikko Blue is my favorite. There are just so few things that bloom that true blue in the garden.”
    
The best time to cut hydrangeas for a dried flower arrangement is later in the season; once they’ve passed their prime, let them dry a bit on the plant before picking. By late summer, the petals start looking more bluish, sepia, and pleasantly vintage. Even later and they might be more burgundy. To get the colors you want, experiment with cutting them at different times between 
August and October. For the month of July, though, 
it’s enough just to sit back and watch them grow, 
whatever the color.

For more information, go to hydrangeashydrangeas.com.