Hydrangea arborescens ‘Annabelle’ will grow to a height and spread of 2m / 7ft after four or five years. Without a shadow of doubt the main interest of this shrub is the large number of huge white flowers produced from late July to early September. In ideal conditions the flowers can reach 25cm / 10in across.

How long does it take for a hydrangea to grow to full size?

But they look fine and bloomed fine this season. The point is that they can take 1-3 years to become larger and established as the roots grow. Do not measure their progress in terms of height or blooms.

How do I speed up hydrangea growth?

How to Get More Smooth Hydrangea Flowers: Plant smooth hydrangeas in full sun if the soil stays moist. Water them during times of drought, especially during the heat of summer. Amend the soil with organic matter (such as compost). Prune stems back in early spring, just before new growth emerges.