We love Hydrangea 'Blue Billow'! This plant
is one of those shrubs that always looks great whether in flower or not.
The foliage is two-toned,with green and dark bronze shading that lasts from
mid spring until late fall frost, when the color turns to a tasty plum-red
color. Growing wider than tall, 'Blue Billow' is one of the most compact
of all of the serrata hydrangeas, so will fit into smaller gardens. Blooming
is reliable in shady areas where it is most happy. Combine with gold foliaged
Hakonechloa for a feast for the eyes.
The flowers of some hydrangea
cultivars can be changed from pink to blue or visa-versa. This is accomplished
by changing the ph of your soil. Some soils, however, are so alkaline or
acidic that it is just about impossible to change their ph, so this technique
is of no value. But if you are growing in a large container, then you have
more control. Start with an acid soil mix to encourage blue flowers, or
a soil mix that is slightly more alkaline to achieve pink flowers. Aluminum
Sulfate is often used to give richer blue or purple color. This chemical
is toxic, so care must be taken in the application. One to two tablespoons
can be dissolved in a gallon of water and applied around the dripline. Be
careful not to get any on the leaves or you will burn them. This should
be done 2-3 months before blooming begins to get the best results. For pinker
colors add dolomite, which is a good plant food and is safe to apply at
any rate.