by Jan Cashman

People driving by in August ask us about the showy shrub planted on the northeast corner of our house full of huge, round, white flowers.  It is an Annabelle Hydrangea.  There are many species of hydrangea, all native to China, Japan, and Korea.  This late-summer blooming shrub does best planted in partial shade.  Ours is on the shady side of our house under a mature flowering crab apple.  An east exposure with some morning sun would be a good location for a hydrangea.  They prefer acid soil, so, to keep their leaves from yellowing, amend your soil with peat moss and a soil acidifier and use a fertilizer for acid-loving plants such as Miracid.

Smooth Hydrangeas

Hydrangeas of the species arborescens, common name Smooth Hydrangea, grow to 3 to 4 feet in height and a spread of 4 to 5 feet.   Annabelle hydrangea’s (Hydrangea arborescens ‘Annabelle’) deep green foliage contrasts with its pure white blossoms.  From when the buds appear, until well into fall when the huge blossoms, some as big as 9” across, turn a light, sage-green color, this shrub is spectacular.   Until recently, hydrangea from the species arborescens had only white flowers.  A new selection called ‘Incrediball’ is supposed to have more and bigger blossoms, but the flowers are white like Annabelle.  This year ‘Bella Anna’ Hydrangea was introduced with purple-pink flowers!  We planted a Bella Anna this summer to see how it does; it is listed as USDA Hardiness Zone 3, so it should be as hardy and easy to grow as Annabelle.  These two new varieties of Hydrangea arborescens are bred to have stronger stems that don’t droop when the flowers get wet and heavy.

Mop Head Hydrangeas

Macrophylla, another species of Hydrangea, are listed as hardiness zone 4, but don’t always thrive here.  Also called ‘Mop Head’ macrophyllas are 3 to 4 feet in height and 4 to 5 feet in width, similar in size to Hydrangea arborescens.  The new, much-touted ‘Endless Summer’ Hydrangea is supposed to bloom all summer with pink or blue blooms.  We have a few customers growing them successfully here.  ‘Blushing Bride’ (white flowers) and ‘Twist and Shout’ (pink or blue flowers with red fall leaf color) are two new macrophylla introductions.

PeeGee and Oak Leaf Hydrangeas

Hydrangea paniculata (Zone 4 hardiness) is an upright plant, growing to 8 feet in the right climate.  Its white flowers are smaller and more conical, turning pink-bronze late in the summer.  Unlike other hydrangeas, most of the paniculatas bloom on last year’s wood like lilacs do, so cutting them back will hinder next year’s flowers.  Again, many new H. paniculatas have been bred for flower color, size, and abundance.  Hydrangea quercifolia (Oakleaf Hydrangea) is Hardiness Zone 5, so probably not a good choice for our climate.

Climbing Hydrangea Hydrangea anomala, subspecies petiolaris, is a Zone 5 climbing vine. Although beautiful, it is doubtful climbing hydrangeas will survive here because they don’t like our dry heat and our winter temperature extremes could cause them to freeze back.  The colorful hydrangeas sold as gifts by florists around Easter won’t overwinter when planted outside here.

Hydrangea flowers are great for drying, but if picked too early in the summer, the flowers will shrivel up.  Wait to pick the blossoms until fall approaches and they have turned from white to pale green.  Most hydrangeas’ leaves are not colorful in the fall—they turn brown and wilt after a couple of frosts.  Probably because it is planted so close to our front door, deer don’t bother our hydrangea until they get really hungry in the early winter, when they ‘prune it back’ for us.  You should protect your hydrangeas if you have deer around.

It’s not too late to plant a hydrangea this fall–or wait until spring.   Find a shady east or north exposure in your yard, and enjoy this beautiful shrub.