Hydrangeas generally begin to develop buds in mid-to-late spring and start blooming in early summer. The exact timing can depend on the type of hydrangea and the climate. For example:

• Bigleaf hydrangeas bloom from late spring or early summer through fall.
• Bracted hydrangeas bloom from late summer through early fall.
• Smooth hydrangeas bloom from early summer through early fall.
• Cascade hydrangeas bloom from late spring through summer.
• Climbing hydrangeas bloom from late spring or early summer through late fall.
• Mountain hydrangeas bloom from mid-summer through early fall.
• Oakleaf hydrangeas bloom from late spring or early summer through fall.
• Panicle hydrangeas bloom from mid-summer through fall.

Hydrangeas usually bloom on old wood or new wood depending on the variety. Old wood hydrangeas bud in autumn and bloom the following spring and summer, while new wood hydrangeas bud in spring and bloom in summer or early autumn. Proper timing for pruning is crucial to protect buds and ensure blooms. They thrive best in rich, moist soils with some shade (morning sun and dappled afternoon light). Fertilizing with a slow-release, bloom-boosting fertilizer and watering regularly also promotes healthy blooms. Avoid pruning at the wrong time, especially in winter or early spring for old-wood hydrangeas, as this can remove the buds and prevent blooming. In summary, your hydrangeas will likely bloom starting early summer and could continue blooming into fall, based on their type and care conditions.