Choosing the right Hydrangea

There are somewhere around 49 distinct varieties of Hydrangeas and each of these varieties belongs to one of six species. These six species all have distinct characteristics including size, hardiness, bloom color and growth habit.

The Big Leaf Hydrangea or Hydrangea macrophylla contains three sub-types; lacecaps, mopheads and mountain hydrangeas. Lacecaps exhibit flat-topped flower clusters while mopheads have a more rounded shape and produce longer-lasting blooms. These popular Hydrangeas are hardy in zones 5-9 but some varieties may require winter protection during our harsh Iowa winters. Considered an old wood hydrangea, it’s important to note that some varieties bloom on new and old wood. These hydrangeas can be found in many colors including pinks, white, purples and blues.

The Mountain Hydrangea (Hydrangea serrata), technically a sub-category of the Big Leaf Hydrangea, is often classified as it’s own distinct type of hydrangea. This hydrangea is much more cold tolerant than the other Big Leaf types, stands smaller in stature and exhibits much smaller flowers in blue and pink.

The Panicle Hydrangea or Hydrangea paniculata is beloved as an easy-to-grow new wood hydrangea. Hardy in zones 3-8, the panicle is cold tolerant and will survive even the harshest of Iowa winters. Although most hydrangeas prefer to grow in areas with part shade, the panicle blooms best in full sun. Many paniculata cultivars are available and the characteristic cone-shaped blooms can be found in white, green, pink, red or burgundy.

Smooth Hydrangeas, Hydrangea arborescens or Annabelle hydrangeas are a North American native plant and is cold tolerant to zone 3. These new wood hydrangeas produce flowers in white or green.

The Climbing Hydrangea, or Hydrangea anomala exhibits a much different growth habit than the other 5 types. Climbing up to 50 ft in height, the climber is a slow grower and is hardy in zones 4-8. These old wood hydrangeas produce white blooms that attract pollinators, including butterflies and bees.

Oakleaf Hydrangeas (Hydrangea quercifolia) are named for it’s large, oak shaped leaves. This old wood hydrangea is unique as it exhibits attractive fall colors with foliage changing from green to orange, red and brown. Just like the Big Leaf Hydrangeas, Oakleaf varieties are hardy in zones 5-9 but some are more sensitive and may benefit from additional winter protection.