Incrediball Hydrangea Planting, Pruning, and Care

Incrediball hydrangea (photo) is so called due to its massive flower head. It's incredible!
Incrediball hydrangea is named for its massive flower head. David Beaulieu

Incrediball hydrangea is a broadleaf, deciduous flowering shrub. Like the Annabelle hydrangea, it is hardy and flowers on new wood, but Incrediball has stronger branches and bigger flower heads than the Annabelle. They will grow in USDA plant hardiness zones 4 through 9 and are potentially hardy to zone 3 in a suitable microclimate.

Incrediball Hydrangea Taxonomy

Plant taxonomy classifies this shrub as Hydrangea arborescens 'Abetwo' Incrediballâ„¢. The cultivar name is 'Abetwo,' while "Incrediball" is a trademark name. "Incrediball" was presumably chosen as the name to trumpet the impressive size of the "balls" of flowers (i.e., rounded flower heads). Unfortunately, the name will inevitably be misspelled by many as "Incredible."

Incrediball Hydrangea Characteristics

Incrediball hydrangea plants exhibit an upright growth habit and will reach a height of 4 to 5 feet, with a similar spread. Flower heads (composed mainly of sepals) are large, up to 9 inches across, and possibly larger. The color is white at the flowers' peak, although they start out with a hint of green, which returns as the flower head ages. In many climates, the shrub typically begins blooming in late June and continues flowering into fall.

Sun and Soil Requirements

Incrdiball hydrangea grows in full sun to partial shade, and the latter is preferable in dry climates. Plant it in rich garden soil that will keep the roots moist. Unlike some other hydrangeas, Incrediball's flower color is not affected by soil pH; this is a white hydrangea plant, pure and simple. Additional watering usually is required during hot, dry weather.

Incrediball vs. Annabelle Hydrangea

Incrediball hydrangea plants were originally marketed as an improvement on the Annabelle hydrangea. Annabelle had been highly valued for its hardiness, the size of its flowers, and the fact that it blooms on new wood. But Annabelle's branches tend to flop over easily in the rain, as water accumulates in the flower heads.

This led gardeners to seek an Annabelle-like hydrangea shrub with stronger branches, and the Incrediball was born. Its flower heads turned out to be even bigger and more floriferous than the Annabelle's, but the branches' ability to support the huge flowers isn't always reliable. Many gardeners find that branches with the largest flowers tend to droop and may even snap off after a rain.

Wooden bench set in hydrangea border (Hydrangea arborescens) 'Annabelle', September
Annabelle hydrangea. Cora Niele / Getty Images

Landscape Uses for Incrediball Hydrangea

Incrediball hydrangea plants can be used in the landscape in a number of ways. These shrubs are attractive enough to be used singly as specimen plants. Some gardeners choose to grow them en masse along a property line to form a border, while others include them in foundation plantings. Their shade-tolerance makes them suitable for woodland gardens, although they may produce larger flower heads in full sun than in partial shade. Incrediball hydrangeas are plants that attract butterflies.

Pruning Incrediball Hydrangea

Incrediball hydrangea plants and other hydrangea shrubs in the native American "smooth leaf" (arborescens) group (including Invincibelle Spirit, another variety inspired by Annabelle) bloom on new wood. Consequently, the question of when to prune is greatly simplified, because there is no issue of losing flower buds that formed on old wood (the prior year's growth). For the same reason, flower buds won't be killed during a cold winter.

Prune Incrediball hydrangea plants (if, indeed, any pruning is called for) anytime between the first hard frost of fall and early spring. Depending on your preference, you can make pruning cuts right down to the ground, as new shoots will be generated. Most gardeners opt for an early-spring pruning, taking advantage of the visual interest the dried flower heads add to the fall yard. Because the flower heads consist mainly of tough sepals, they persist right through autumn (although the color does fade to a tan). People often cut some of the flower heads for use in dried arrangements.