Three Tips to Get Your Mophead Hydrangeas to Bloom Beautifully

A look at how I get my Hydrangea macrophylla 'Endless Summer®' shrubs to bloom beautifully in my New Jersey garden.

With their blue or pink "mopheads", hydrangeas are an emblem of summer. Having them in my landscape conjures up visions of wind-swept summer walks in Nantucket or Martha’s Vineyard. Since we have a coastal-style Cape Cod home, they were a “must” in my mind when I designed our garden.

'Endless Summer' Hydrangeas

I've experimented with how to get them to look their best and have a learned a few things over the years.

'Endless Summer' in June of 2020 (left) versus June of 2021 (right)

Take a look the year-over-year picture above. Notice how on the left, the plants pictured in June of a prior year don't have many flowers but that the same grouping of plants on the right which I photographed a year later are just loaded with blooms. You might be wondering what made the difference. I attribute the better performance to three key factors.

Rose Tone is a big part of my fertilizing routine

First, I changed my fertilizer. In the past, I used Espoma Holly Tone. However, before the more recent picture, I switched to Espoma Rose Tone, which works with any woody flowering shrub - and is recommended by Proven Winners. I really felt this made a huge difference!

Wrapping with burlap as frost approached

The second change was that when the early spring frosts threatened after our "false spring", I got out there and took the time in to tent them with burlap as shown (Note: photo was taken halfway through the process - I eventually wrapped the whole group of hydrangeas). Because it was difficult to tent such a large plant (actually three plants grouped together), I decided that going forward, I would pre-position the sticks in the planting bed each March so that the infrastructure would be in place and ready to go. Anything to minimize what can be a tricky task in the biting winds of an approaching frost! Third, for the more recent picture, we generally had great luck with a smooth transition to spring. As plants that bloom on "old wood", mophead hydrangeas need a steady and smooth progression in transition to spring, without a lot of advances and retreats in the weather. Late frosts after the plant has broken dormancy can often damage their beautiful blooms which were set on the plant the summer before. The weather hit the spot. All these factors helped my mopheads thrive and created the beautiful blooms you see on the right.

Mophead hydrangeas definitely demand a bit of extra attention but when the early spring weather cooperates (and if you can protect them from late frosts), they really add a quintessential summer vibe to the garden.