Lime - however once they start turning it is hard to get them back to the red because our soils are so acid. Mine turned purple the second year even with additional lime. At least I still have the red veining in the leaves.....

Lynne

Are you sure they aren't going to color up? I don't have Lady in Red, but I know the (Nikko blue) blooms I get on my hydrangeas start out a greenish white and take a while to turn blue. And supposedly it takes time for the pH to change bloom color. My soil is sandy and has an oddly high pH. I have been attempting to lower the pH with coffee grounds, a bit of sulfur and also hollytone. My Nikko blues have been in the ground 3 years, and only this year did I detect any change in the blue color they started out with, despite my high pH. There is just a hint of lovely purple this year, and I had to look hard for it.

These look awful white not to remain white. Wish I had realized about the color before I purchased the "red" one. Now I could deal with purple! Thanks for the info. plantbug

From Marie Iannotti (see link):
Hydrangea macrophylla ÂLady in RedÂ

Hardiness: USDA Zone 6-9
Mature Size: 2' H x 3' W
Exposure: Partial Shade
Period of Bloom: Early spring into summer
Bonus: High Mildew Resistance

H. macrophylla ÂLady in Red offers more than exceptional blooms. This lady provides three seasons of interest. The red stems and red veined leaves are the first indication that this is no ordinary hydrangea. The lacecap blooms open in late spring as either a whitewashed pink or blue, depending on the soilÂs pH. Either way they will slowly mature to a lush burgundy rose, echoing the colors of the stems and veins. Come fall even the leaves change to a rich purple.

Here is a link that might be useful: About-dot-com site