"I'm a Professional Flower Grower — This $5 Buy is my Secret to Longer Lasting Cut Flowers" — Try This Viral Hack

If you want your cut stems to last longer, there's an industry secret you need to know about — and it's budget-friendly, too

hydrangeas in a vase
(Image credit: Funny How Flowers Do That)

Do you ever buy flowers from the grocery store or elsewhere, hoping they'll brighten up your home for a while, only to wake up to wilted blooms sooner than you'd expected? Some cut flowers last a lot shorter time than others, but sometimes those are the ones that look best in your vase.

Hydrangeas, for example, famously have a short shelf life. If you don't buy the very freshest hydrangeas from the store, you may end up with them only lasting a day or two.

However, speaking to a professional flower grower, I learned a great secret about how to keep these blooms alive. 'As a flower-farmer, I’d love to share a tip that has saved me many finicky cut-hydrangea blooms, in particular,' says Meredith Bishop, founder of Bloom & Beauty, and it involves something you can buy for less than $5 at a grocery store. Here's how to take care of hydrangeas in a vase with a simple trick.

What's the secret to longer lasting hydrangea?

hydrangeas in vases on a table

(Image credit: Funny How Flowers Do That)

So what's the secret? 'One, always cut in the coolest part of the day (morning or evening) straight into water,' Meredith says — something that applies if you're growing your own hydrangea, not getting them from the store. 'Next, scrape a bit (1/2” or less) of bark off the stem at the cut point. Finally, dip the cut end into alum powder and replace in fresh water,' she says.

Cut hydrangeas aren't long lasting flowers, usually only keeping for 4-5 days generally, but 'blooms should last for around a week or more with alum,' Meredith says. Some people who use alum powder on hydrangea say it makes their flowers last for weeks and weeks.

meredith bishop
Meredith Bishop

Meredith Bishop is a sustainable flower grower specializing in old-world blooms grown from seed in her gardens in urban Nashville, Tennessee. She also operates a retail design studio in Nashville, and enjoys teaching, speaking and writing about all aspects of flower gardening.

What is alum powder and how does it work?


A floral hack for my fellow hydrangea lovers!

♬ original sound - Kathleen Ashmore

So what exactly is alum powder? 'It's a spice in the onion family found in the spice aisle of most grocery stores,' Meredith explains, but why does it help your hydrangeas last longer?

Well, as it turns out, the clue to happy hydrangea is in the name. Hydra-ngea — they love water. The only problem is, when you cut hydrangeas, they stop wanting to actually take water up their stems. Once you dip your stem in the alum powder, it will start to drink up the water from your vase, helping your blooms last a lot longer.

What else can help extend the life of your hydrangea?

There are a couple of other tricks you can use to keep hydrangeas looking fresh, too. The problem with cut hydrangea stems is that air or sap can block them from taking up water, which is where alum powder helps. However, you can also cut the stems and then submerge them in boiling water for a few seconds, which can help with this too.

Hydrangeas are also the only plant that can actually take water in through their petals, too. With that in mind, you can submerge hydrangea in cold water for an hour or so to give them a hydration boost that will also help them last longer.

Hugh Metcalf
Editor of Livingetc.com

Hugh is the  Editor of Livingetc.com. From working on a number of home, design and property publications and websites, including Grand Designs, ICON and specialist kitchen and bathroom magazines, Hugh has developed a passion for modern architecture, impactful interiors and green homes. Whether moonlighting as an interior decorator for private clients or renovating the Victorian terrace in Essex where he lives (DIYing as much of the work as possible), you’ll find that Hugh has an overarching fondness for luxurious minimalism, abstract shapes and all things beige. He’s just finished a kitchen and garden renovation, and has eyes set on a bathroom makeover for 2024.