The pot must be large enough for the plant to grow and deep enough for the hydrangea to develop a sufficient root system.
The right potting mixture allows for water retention and good drainage. Hydrangeas prefer moist, rich, loam soil that drains well.
Because they are unable to pull moisture and nutrients from surrounding soil, potted hydrangeas need regular watering and fertilizing.
Gardeners can move potted hydrangeas to sunnier or shadier areas as needed. In colder climates, they can move the hydrangeas to an unheated garage or basement to protect the plants during colder months or move them to a protected location outside, away from high winds.
After a number of years in pots, the roots of hydrangeas become pot-bound if not pruned. Pruning also reduces the growth rate of the plants. To prune, remove the plants from the pots and cut the roots, but not by more than a third.