One of my most viewed videos on Facebook @askfrankieflowers.com is “when to prune hydrangeas?” This is one of the most frequently asked questions I get. So, let’s break it down for you here.

The Two Types of Hydrangeas

There are two basic types of hydrangeas: Hydrangea paniculata and Hydrangea macrophylla. Within these two basic types there are several varieties, but these two types have one huge difference: when to prune.

Hydrangea paniculata blooms on new growth, meaning pruning these in late fall or earlier spring pretty aggressively. I prune my Hydrangea paniculata at least half their overall size each season.

In contrast, Hydrangea macrophylla blooms on old wood, so if you prune these guys in late fall or early spring you are cutting off all your flowers. I recommend only removing large spent flowers in late fall and in spring, waiting for hydrangeas to bud and removing only dead wood or those stems that appear brown with no buds.

Pruning Hydrangeas for Success

Pruning at the right time is key for successful flowering of hydrangeas. If they are not blooming, you most likely are pruning at the wrong time of year. However, hydrangeas that lack blooms can also be a result of lack of sunlight or even the wrong application of feed. Most hydrangeas require part to full sun and benefit from light feeding.

The Hydrangea macrophylla will even alter bloom colour from pink to blue based on the acidity of the soil (acid soil flowers are blue, alkaline soil flowers are pink).

My Favourite: Paniculata versus Macrophylla?

While flower size, shape and colour differ for each, hands down, my favourite is paniculata. Why? From an ease of growing and performance factor, hands down Hydrangea paniculata wins. They are vigorous growing, forgiving and easily produce blooms for long periods of time.

Macrophylla hydrangeas are beautiful when they do flower, but for many Ontario gardeners they just produce an abundance of foliage and very minimal flowers. They are frustrating, very particular when and how to be pruned and they are not typically as hardy as paniculata.

My Favourite Variety of Paniculata?

A tough question to answer. I love Hydrangea “Incrediball” for its huge global white blooms on strong sturdy stems that don’t need staking. Incrediball gives the traditional look of Annabelle Hydrangea without the work.

Hydrangea “Limelights” is almost tied for first, with huge ice cream cone-shaped blooms that turn from chartreuse to pink as they mature. Finally, one grabbing my attention is Hydrangea “Quick Fire,” whose white coned shaped blooms mature to a brilliant red late in the summer season. Long-lasting bloom, easy to grow and grabbing loads of attention — why choose another? 

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With hydrangeas, your success depends on choosing the best variety and knowing when to prune. May your days ahead be blooming great!