A Guide to Pruning Hydrangea

As a landscape designer, I am often questioned as to when and how to prune the various types of hydrangea. The next welcome addition to your landscape could be one of the many show-stopping varieties of this plant and proper pruning is the key to successful blooms!

Hydrangea ‘Nikko Blue’

Generally, hydrangea either bloom on the “old wood” of the previous season, “new wood” of the current season or a combination of both. There are many types of hydrangea including the mopheads, lacecap, panicle, mountain, smooth, oakleaf and climbing. The Mopheads (Hydrangea macrophylla) have been the most widely planted hydrangea in home landscapes over the years and are usually blue or pink in color with large leaves. Hydrangea ‘Nikko Blue’ is very well known in the landscape for its large blue ball-shaped flowers that bloom towards the later part of the summer and deepen in color as they mature. ‘Nikko Blue’ Hydrangea does bloom on old wood, which means that if you are looking to prune your plant it needs to be done immediately after flowering before the fall. Hydrangea ‘Nikko Blue’ grows best in moist, well-drained soil in partial shade. It reaches 3-5 feet in height and is hardy to USDA Zone 5. 

‘Endless Summer’ Hydrangea

A newer alternative to the “old fashioned” variety of hydrangea is the Hydrangea ‘Endless Summer’ collection, which blooms on both old and new wood and ‘All Summer Beauty’ that blooms on the new growth of the season. Both of the later mentioned also have a much longer bloom time and repeatedly bloom throughout the summer. Each of these plants grows to approximately 3-5 feet in height, each grows best in partially shaded conditions (afternoon shade) and moist well drained soil and are hardy to USDA Zone 5. Hydrangea macrophylla ‘Blushing Bride’ in the Endless Summer Collection displays white blooms that turn pink with age. For these varieties that bloom on the “new wood” of the season, spent blooms and dead wood from the inner portion of the plant can be pruned out in either fall or early spring.

Dwarf Hydrangea ‘Pia’

Hydrangea ‘Pia’ is a miniature French hybrid with broad pink flowers growing only to 2 to 3 feet in height, a good candidate for small spaces in zones 5-9. ‘Pia’ grows best in partial sun with afternoon shade and prefers a rich organic soil. Pia hydrangea bloom on old wood and generally need little to no pruning; however, if needed, prune immediately after flowering by cutting back flowering stems to a point of healthy buds. An alternate that blooms on the new wood of the season is the Cityline Series from Proven Winners, a dwarf hydrangea hybrid that matures to just 2-3′ tall by 3-4′ wide.

Hydrangea ‘Tokyo Delight”

Another variety of Hydrangea ‘macrophylla’ is the Lacecap Hydrangea that displays a smaller inner circle of lace-like flowers surrounded by a ring of larger showier flowers. A favorite is Hydrangea ‘Tokyo Delight’ that displays beautiful cobalt blue flowers with an inner ring of delicate white flowers, grows to 4-6 feet and blooms late July through August, prefers afternoon shade, moist well drained soil and is hardy to USDA Zone 6. Prune Hydrangea ‘Tokyo Delight’ immediately after bloom since new buds form on the older wood from the previous season. An alternate lacecap hydrangea that blooms on both old and new wood is Hydrangea ‘Twist-n-Shout’ from the Endless Summer collection with beautiful blooms that turn to a purple-blue in a more acidic soil. Twist-n-Shout’ is hardy is USDA zones 4-9, grows 3-5 feet tall by wide and like all plants in the Endless Summer Collection, produces blooms on both old and new wood.

‘Pee Gee’ Hydrangea Tree Form

Hydrangea paniculata ‘Grandiflora’ or the ‘Peegee’ Hydrangea is a personal favorite of mine for extremely large pyramidal white blooms in July throughout fall and abundant fragrance in the garden. Hydrangea ‘Peegee’ can be grown as a shrub or tree form and can serve as either a group planting or as a single specimen in a landscape design. Hydrangea ‘Grandiflora’ also grows 3-5 feet or higher in its tree form. This particular hydrangea can grow well in full to partial sun and blooms on new wood. Sent to the US from Japan in 1861 this beauty is a showpiece in the garden and is hardy in Zones 4-8.

Hydrangea ‘Tardivia’

Panicle hydrangea are known for being the most cold hardy and are very tolerant of pruning.  They can reach a height of ten to fifteen feet or can be pruned to keep more compact.  For a similar look to ‘Peegee’ with creamy-white panicle-shaped blooms and a more open look is Hydrangea ‘Tardivia’. Hydrangea paniculata ‘Limelight’ is a newer introduction with beautiful elongated lime colored panicles that bloom in late summer and last through fall. Hydrangea ‘Tardivia’ and ‘Limelight’ (6-8 feet high by wide) both do best in full to partial sun and bloom on new wood. Hydrangea ‘Little Lime’ is a more compact version of ‘Limelight’ and also blooms on the new wood of the season.

‘Annabelle’ Hydrangea

Hydrangea arborescens ‘Annabelle’, a native of the U.S., is a more shade tolerant hydrangea that produces showy ball shaped white blooms in summer, grows 3-5 feet in height and is hardy to USDA Zone 3. ‘Annabelle’ blooms on new wood and can be severely pruned in winter in order to restore shape. 

Oakleaf Hydrangea

The last two varieties of hydrangea are Hydrangea quercifolia or ‘Oakleaf ‘Hydrangea and Climbing Hydrangea. The Oakleaf hydrangea serves as an excellent plant for massing in a woodland setting. The name ‘Oakleaf’ comes from the oak-shaped leaves that turn a bright mahogany red in fall for a brilliant display. The upright panicles of large white flowers appear in June and the plant has a rounded habit, grows 4-6 feet in height and is hardy to USDA Zone 5. Hydrangea quercifolia does well in partial shade in a well drained most soil. This hydrangea blooms on old wood and should be pruned immediately after flowering. Climbing Hydrangea (H. anomala petiolaris) is an upcoming variety becoming more popular in the landscape. As the name implies this hydrangea once established produces vigorous vines and a profusion of lightly scented blooms. Climbing Hydrangea bloom on “old wood” from the previous season.

For more gardening tips Visit my Author Page

A Guide to Northeastern Gardening: Journeys of a Garden Designer 

Landscape Design Combinations

Dream, Garden, Grow!-Musings of a Lifetime Gardener

Lee Miller@Landscape Design By Lee 2020. All Rights Reserved.

Spring Maintenance of Birch, Boxwood and Hydrangea

Once mid-late spring rolls around, you may notice that some of your landscape plants are in need of some tender loving care. After the lack of snow in some parts of the northeast and prolonged frigid temperatures in the single digits this past winter season, certain plants have been more affected than others by the lack of insulation from snow cover and extreme cold. Another factor affecting the vitality of your plants could the abundant rainfall amounts hitting the eastern seaboard.

Winter Die Back on Weeping Birch

Birch trees are one species that the winter has especially taken a toll on. By this time in June, Birch trees should have pushed out most of their new foliage, but you may notice some bare branches and empty spots on your tree. If that is the case, gently scrape the bark or cut a tip off bare stems to see if there is any sign of green. If the cambium growing layer underneath the bark is green, give the tree a little more time to see if it will push out any new growth from those branches. If the layer below the bark is brown, remove the dead branch from the tree to help direct growing energy to where it is needed. Give the tree a good feeding (preferably a deep root application) and some time. The tree should gradually show signs of recovery and continue to regain its health.

Iron Deficiency on Boxwood

Boxwood is another plant which has been affected by the recent weather abnormalities. If your boxwood is looking a little paler than usual with some yellowing in the leaves, it could be a sign of iron deficiency. The abundance of rain here in the northeast has literally “washed” away much of the iron in the soil. Iron chlorosis can develop under conditions that reduce the availability of iron to the plant, such as a combination of cooler than normal temperatures and poor root aeration or soil drainage due to constant moisture. To remedy the lack of iron, apply a liquid iron solution to the soil around your plants. Most supplements will work over time to restore the plant back to good health.

Winter Die Back on Hydrangea

Hydrangea are another plant showing signs of winter damage over the past several years here in the northeast and over other parts of the country. If your Hydrangea is still showing bare stalks above new growth now in June, and stems appear dead, simply prune off the damaged wood to beneath the line of new foliage. As with most flowering plants, application of a plant food that is high in phosphorus in mid-late spring will encourage buds.

Routinely checking your garden in springtime can catch early signs of plant distress and help in avoiding more serious issues down the road. During springtime and throughout the ongoing growing season, early detection of plant issues is a worthwhile practice, After all, a little preventive care can go a long way!

For more gardening tips and design inspiration along with personal musings…

Visit my Author Page/Purchase My Books:
A Guide to Northeastern Gardening: Journeys of a Garden Designer Landscape Design Combinations
Dream, Garden, Grow!-Musings of a Lifetime Gardener

Lee Miller@Landscape Design By Lee 2019. All Rights Reserved.