The different varieties of hydrangeas – oak leaf hydrangea, pinky winky hydrangea, vanilla strawberry hydrangea, quick fire hydrangea, endless summer hydrangea, nikko blue hydrangea, little lime hydrangea, etc. – normally thrive well under indirect sunlight. But it is best to know exactly the ideal planting conditions for the hydrangeas that you are planning to grow in your yard or in pots.
Generally, all hydrangeas bloom and grow well when subjected to the morning sun and the afternoon shade. This is especially true for the common macrophyllas -- the blue and pink mopheads and lacecaps. The further north or zone you live in, the hardier the hydrangeas can get; they can withstand more sun.
There is no hydrangea variety that will bloom and thrive in heavy shade; it will not flower at all. Heavy shade means something growing under an oak tree, which is a spot that is hard for sunlight to reach. If grass doesn’t grow on a location where you are planning to plant, then the hydrangeas will not grow either.
If your area is prone to sunny and hot weather, then you must grow PeeGee (paniculata) hydrangeas; these are hardy and can soak in full sun daily as long as adequate watering is provided. Paniculatas require at least 5 hours of sun every day to bloom well.
The white oak leaf hydrangeas will grow in either sun or shade, but their flowers will last longer if they get afternoon shade in areas with hot climates. The leaves of the oak leaf hydrangea will gain a beautiful pinkish or reddish color during the fall if the shrub receives a little sun.
To plant hydrangeas regardless of the variety, you must plant in a location where they can reach their full size without pruning. For normal sized varieties of hydrangeas, expect a maximum reach of around four feet square. The soil must drain well. If it doesn’t, then add roughage like pine bark mulch. Never over water your hydrangeas, especially if the soil is of the clay type. It can lead to fatal root rot. Also, do not plant the shrub too deeply into the soil. Do your planting during the early summer or in the late fall. When transplanting a hydrangea, you must do it when the shrub has turned dormant and just lost all of its leaves; this happens during late fall or winter. Finally, never plant hydrangeas during the hottest days of summer.