How to prune repeat blooming hydrangea

I have received a lot of questions this month about how and when to prune bigleaf hydrangea (Hydrangea macrophylla), especially the newer 'repeat blooming' varieties.

What are repeat blooming hydrangea?

Summer Crush is one of the Endless Series of reblooming hydrangea. The vivid raspberry blooms often show an apple-green eye

These are the varieties which bloom both on the growth they put on last year (called old wood) as well as the growth that occurs this year (new wood). The benefits are significant:

• You'll get two waves of flowers: the first on the old wood, then just as they begin to fade to those delicious antique shades the second wave of flowers will appear on the new wood
• A late spring frost may damage buds on the old wood – but the new growth emerging from the base of the shrub will still grow and bloom, albeit it later
• Even if you prune incorrectly you'll still get some flowers!

Examples

The flower colors of Bloomstruck vary from deep blue-purple to lavender with a pale yellow eye. I especially like the dark stems on this variety which add interest even before flowering begins

Both the traditional mophead and more delicate lacecap flower heads are available as repeat-bloomers. Here are some of the very best:

• Endless Summer Collection
• Seaside Serenade Series (all except Bar Harbor re-bloom)
• Let's Dance Series
• Bloomin' Easy Collection

How to Prune

Knowing that these will bloom both on old and new wood instills fear in many gardeners, concerned that they don't inadvertently prune out the first flower buds. For those of you who like demonstrations here's a great video to help you:

As a side note, if you have healthy buds both on last years stems as well as new growth emerging from the base, yet have a few extra-long branches that are spoiling the overall shape, make cuts where I have indicated with a red line.

You can reduce the length of the rogue stems in order to shape the shrub and will only sacrifice a few flowers

Spring pruning is also a good opportunity to fertilize and remove any winter mulch. I found this Spring Checklist really helpful and it includes video links too.

PS: Many areas of the country are experiencing a significantly delayed spring in their gardens and I'm no exception. My hydrangeas are still dormant  – they would usually have plenty of buds by now. The only canes showing green buds are those protected by the house eaves. Be patient – they should start to wake up in the next few weeks.

What's Your Favorite?

Pistachio is not for the faint of heart – the colors in this are remarkable.

I really wish the deer weren't so partial to hydrangea -I have to keep mine well away from their preferred routes and spray with a repellent! My personal favorites are Bloomstruck (for the dark stems as much as the bloom color), Pistachio and Tilt -A – Swirl (both of these have similar, mouth-watering, multi-colored blooms).

What's yours?

Additional Resources

Companion planting ideas