Answer: The answer to your question depends on which type of hydrangea you are growing. Often poor blooming is related to insufficient age or incorrect pruning. Since five years should be long enough to expect good flowering, then we would suspect either winter damage or poor pruning. Some of them such as PeeGee Hydrangea in the paniculata group are simply huge tall shrubs but can be pruned in late winter or early spring without harming the flowering. Hydrangea quercifolia (Oakleaf hydrangea) blooms on old wood so pruning should be done immediately after flowering. It is very difficult to prune the macrophyllas for size control but any pruning of this group should be done immediately after flowering. Finally, the hydrangea arborescens such as "Annabelle" can be cut off at the ground each spring and will regrow and bloom happily each year, and it could be divided for size control as well.
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