I Tested the Propagation Tip to Rejuvenate Cut Hydrangeas—and It Works

Hydrangeas are really making a comeback. The blooms are bigger, the colors are brighter, and it feels like they’ve become the official floral symbol of summer.

But if you’ve ever bought cut hydrangeas, you know they don’t last very long. While you can dry and preserve cut hydrangeas, it’s not the same as a fresh bouquet.

So when I saw this tip from Skye Hamilton from @hamiltonhousedesigns to help them last longer, I was intrigued.

The only problem? This hack seems very, very strange!

In summary, here are the steps:

1. When you notice your hydrangeas are wilting or have completely wilted, fill the bowl with cold water.
2. Meanwhile, fill the pot with water and heat until the water does not boil.
3. While waiting for the water to heat, dip each hydrangea flower into cold water.
4. Fill the kettle with non-boiling water.
5. Pour a small amount of alum powder into a bowl.
6. Trim the trunk at a forty-five degree angle.
7. Dip the stem in alum powder.
8. Put flowers in hot water.

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First, buy a hydrangea plant.

I stopped by my local florist and saw that hydrangeas were in short supply. I was a little disappointed at first, but then I realized this might be a great opportunity to see if this trick was cultivar dependent.

I picked three flowers of three different shapes, asked the florist to trim them for me, and put them in a vase of cold water as soon as I got home.

Within hours, Hamilton provided video evidence of your nearly dead hydrangeas coming back to life and blooming. I had to go there to see for myself.

Next, monitor their health and happiness.

For the first day or so, my new hydrangeas did their job: bringing some color and joy to our kitchen. However, within forty-eight hours, the first of the clusters of flowers began to wilt.

I gave it another twenty-four hours and noticed a second flower joining the first on its journey to death. When the petals curled up and lost their color, it was clear it was time to try this trick.

Steps 1-4: Prepare water and dip

The first three steps of this process are nothing too unusual or unfamiliar to me when it comes to caring for cut flowers.

After all, hydrangeas are named for their love of water, so dunking their heads in a cool bath seems like something they’d enjoy. Plus, I think they’re probably used to it in rainy London.

The hot water gives me pause, but I’ve also heard that warm water can help the buds on your cuttings bloom faster. Maybe that’s part of the magic?

Step 5-8: Use alum powder and arrange

This next part was completely new to me. As it turns out, alum is often suggested as a substitute for homemade flower food, so in retrospect it wasn’t so wild. But before that, I only knew it as something most commonly used for pickling or tenderizing meat.

For flowers, however, alum helps the stems absorb more water. This is especially true for woody flowers, like roses and, yes, you guessed it: hydrangeas.

I followed the instructions and dropped the alum soaked stems into the not yet boiling water.

The final result? Great!

I was skeptical about this whole process, I have to admit. Mainly because none of my hydrangeas looked anything like the ones in the original video, and when I decided to try it, the largest of the three looked more wilted and dry than limp and wilted.

My confidence did not improve when about two hours later the flowers still looked the same. Six hours later I saw some improvement, but I also wondered if it was my imagination.

But what about twelve hours later?

The nearly dead stem in the inflorescence was much more vibrant, and the remaining two looked absolutely perfect.

Best of all, it’s an incredibly easy process. It really doesn’t require anything more than my usual bouquet care of occasionally changing the water and trimming the stems, with the only added steps being hot water and alum powder.

Consider me a convert—I’ll definitely be using this trick from now on.