Instructions for the Autumn Hydrangea
While in bloom, the Autumn Hydrangea thrives in medium light with temperatures from 55 to 75 degrees F. Keep soil moist, but not waterlogged.
No fertilizer is required while the plant is in bloom. However, you can use a fertilizer that's formulated for acid-loving plants after the plant has finished blooming.
This variety is hardy in USDA zones 7 to 9. Gardeners in those zones can move the hydrangea outdoors and plant it. The best location is morning sun or dappled shade. For best results in zone 7, mulch the plant in the winter with shredded bark, leaves and/or garden fabric.