A minimum of six hours of sun is recommended for the strongest stems and the most abundant flowers. In hot climates, afternoon shade is beneficial, but some sun is still recommended for the best results.
Avoid pruning Cascade hydrangeas, except to remove any dead wood. These hydrangeas cannot be cut back or trimmed at any time of the year without impacting the bloom for either the current season or the next. Though they do rebloom readily on new wood, the best display comes from treating them as though they bloom only old wood.
A 2-3″ (5-7.6 cm) layer of shredded bark mulch helps shallow-rooted hydrangeas to conserve moisture and keep roots growing vigorously, which ensures the best performance. Fertilize in early spring, after the ground has thawed but before new growth begins, to ensure the best results.