Smooth hydrangeas (Hydrangea arborescens) generally grow 6 -7 feet high, and some wild forms upwards of 10 feet (USDA hardiness zones 3-9). The exceedingly popular Invincibelle® series grow 5-6 feet high. Three recently introduced mini-types (listed below) are perfect for a small garden or in a large container. Shrubs in the series reach full size in […]