Hydrangea Care 101

How to Keep Your Hydrangea Bouquet Fresher, Fuller, and Longer-Lasting

If you’ve ever been lucky enough to receive or treat yourself to a hydrangea bouquet, you’ll know it can steal the spotlight in any room. With their bold blooms, generous petals, and impressive volume, hydrangeas aren’t just flowers, they’re a floral statement. But despite their beauty, hydrangeas are notoriously finicky when it comes to vase life.

So how do you make your white hydrangea or multi-coloured hydrangea flower arrangement last? Backed by scientific research and practical proven techniques used by our growers, ourselves and loyal customers, this complete guide is your new go-to for everything related to hydrangea care.

What are hydrangeas

Hydrangeas are widely loved ornamental plants that originate from regions across Asia and the Americas. With more than 70 recognised species, they grace gardens around the world with striking blooms in shades ranging from pink and blue to white and purple. One of their most intriguing traits is the ability to shift flower colour based on soil pH acidic soils often produce blue blooms, while alkaline conditions lead to pink hues, making them a natural indicator of soil chemistry.
These plants form large, eye-catching clusters, with numerous small flowers surrounded by vibrant bracts that create the lush, full look hydrangeas are known for. This structural beauty has made them a favourite for gardeners and floral arrangers alike, valued both for their elegance and their versatility (The Royal Horticultural Society 2025).

At Floralty, we take hydrangea excellence one step further. Our hydrangeas are grown in their native-like conditions along the equator in South America, where the plants benefit from natural year-round sunlight, optimal humidity, and rich volcanic soil. Unlike many mass-market hydrangeas that are cultivated in energy-intensive greenhouses, ours thrive outdoors, as nature intended, which not only enhances their size, colour saturation, and bloom density, but also significantly reduces environmental impact.

This means when you receive a hydrangea bouquet from Floralty, you're not just getting fuller, more vibrant flowers, you're supporting a growing practice that’s better for the planet. The consistent equatorial climate allows our stems to develop larger flower heads, thicker stems, and longer vase life with no artificial intervention. 

Why Hydrangeas Are So Sensitive

Hydrangeas have earned the nickname "water barrels" because they are incredibly thirsty blooms. Their large flower heads and soft petals lose water quickly through transpiration, making them highly dependent on proper hydration and vase conditions (The Horticulture Journal 2018).

Step-by-Step: How to Care for Cut Hydrangeas

1. Cut Stems at a Sharp Angle

Using a clean, sharp knife or shears, cut each stem at a 45-degree angle. This increases the surface area for water uptake and prevents the stem from sitting flat at the bottom of the vase, which can restrict flow (Kazaz 2019).

2. Boiling Water Treatment

Dip the freshly cut end of the stem into boiling water for 30 seconds. This may sound counterintuitive, but it works. The heat helps break down woody fibers and dissolves the hydrangea’s natural sap, which can otherwise clog the vascular system (StoneGamble 2024).

3. Alum Powder Method

As another option, dip the stem end into alum powder (found in spice aisles). Alum helps prevent sap blockage and supports better water absorption. This method is popular among florists and backed by customer success (Southern Living 2022).

4. Submerge for Revival

If your hydrangea starts wilting, don’t throw it just yet. Submerge the entire bloom (head, leaves and all) in cool water for several hours. Hydrangeas can rehydrate through their petals and foliage (FloraLife Research Update 2015).

5. Mist Daily

Lightly mist your hydrangea flower heads once or twice a day. This helps replenish moisture lost through transpiration and supports longer-lasting freshness (Windflowerflorist 2024).

6. Use Clean Water + Flower Food

Always use lukewarm water and a floral preservative. The biocide fights bacteria, the acid improves water flow, and the sugar provides energy (Growingformarket 2021).

Science-Backed Care Techniques

Hydrangeas have been the focus of multiple scientific studies, confirming that the right care can significantly increase vase life. For those flower lovers that love the science behind these beauties too…

8-HQS Solutions (Kazaz, 2019)

• Using 250 mg/L of 8-hydroxyquinoline sulfate (8-HQS) extended hydrangea vase life by 40%.
• Avoid high concentrations of citric or succinic acids, which can reduce vase life.
  

Glucose Over Sucrose (Amnuaykan et al., 2023)

• A 3–5% glucose solution outperformed sucrose and mannitol in extending hydrangea freshness.
• Glucose promotes stronger water uptake and better inflorescence health.
  

Defoliation + Covering (Kitamura et al.)

• Removing excess leaves and covering the inflorescence suppresses transpiration.
• Less water loss = extended life.
  

Thymol + Sucrose Combo (Kiliç 2020)

• A blend of 150 mg/L thymol and 1% sucrose increased vase life by nearly 6 days.
  

HOCl + CO2 Fertilisation (Kim et al., 2023)

• These advanced techniques improved water uptake and inflorescence size in a controlled setting.
  

Science-Backed Tips Turned Into Easy DIY Steps

You don’t need a lab to get professional-level results at home. Here’s how to translate the science into simple, home-friendly techniques:

• 8-HQS Alternative: If you can’t get your hands on 8-HQS (i will be impressed if you can !), focus on regularly changing the water (every 1–2 days) and keeping your vase sterile. This mirrors the antimicrobial benefit of 8-HQS.
• DIY Glucose Solution: Instead of standard sugar, dissolve 1.5 to 2 teaspoons of glucose powder (available in health stores) into 1 litre of water. This mirrors the effective 3–5% glucose concentration.
• Thymol Substitute: Add 1 teaspoon of thyme essential oil to your vase water. This closely mimics the antibacterial effects of thymol.
• Defoliation Technique: As shown by countless studies, remove leaves that would sit below the waterline and consider trimming extra foliage. This reduces water loss and bacterial risk.
• Water Temperature Control: Lukewarm water, rather than cold, enhances uptake. Changing it frequently mimics the controlled conditions tested in the studies above.
• Mist & Submerge: Combine daily misting and submersion revival methods featured in Country Living’s guide and proven by growers to fight petal dehydration.

These small changes to your routine can make a huge difference in helping your hydrangea cuttings last longer and our biggest flower bouquet shine for days at home.

Special Care for White Hydrangea Bouquets

White hydrangeas tend to be more delicate and show browning or wilting sooner. Mist them more frequently and ensure water is changed every two days. Their petals are more prone to spotting from minerals in hard water, so distilled or filtered water is ideal. Because these blooms lack the pigments found in coloured varieties, they’re more sensitive to sun exposure, placing them in partial shade helps prevent scorching. Their bright petals also reflect heat, which can cause faster dehydration, so keep them in a cool location indoors. Handle flowers gently when trimming or arranging, as the soft petals can bruise easily. 

Understanding Hydrangea Colour & Variety Differences

The care routine is generally consistent across hydrangea colours, whether pink, blue, purple, or white but vase life can vary depending on the cultivar and growing conditions. According to the Royal Horticultural Society (RHS), colour differences primarily arise from soil pH and aluminium availability: acidic soils rich in aluminium produce blue tones, while alkaline soils yield pink blooms. These chemical variations can also subtly influence petal texture and durability, which in turn can affect how long your blooms last once cut.

Cuttings taken at the height of bloom, when petals are fully open yet firm, tend to have the longest vase life. In fact, studies by horticultural experts at North Carolina State University have shown that immediate hydration at the point of cutting by submerging stems directly into cool water can drastically reduce air embolisms and improve longevity across all varieties.

Our growers apply these exact principles. From the way our flowers are harvested at peak maturity, to how they are hydrated and cooled immediately, to our sustainable, fast farm-to-door delivery; everything is designed to deliver hydrangeas that stay fuller, fresher, and more beautiful for longer.

Whether you’re arranging this big flower bouquet for your hallway or gifting an armful of white hydrangeas to a friend, following these proven care techniques will ensure you get the most joy and longevity from every stem.

Frequently Asked Questions: Hydrangea Care

• Hydrangea how to care?

Cut the stems at a 45-degree angle, treat with boiling water or alum, use clean lukewarm water with flower food, mist the blooms daily, and keep them in a cool place. Revival is possible with full submersion in water.

• Why are my cut hydrangeas wilting so fast?

Because hydrangeas are incredibly thirsty and prone to stem blockages. Wilting is caused by:
Sticky sap clogging the stem
Air bubbles (embolism)
Dehydration through large flower heads

• How can I revive my wilted hydrangeas?

Submerge the entire bloom in cool water for 30 mins to several hours. Then, re-cut the stem and return to a clean vase.

• What's the best way to prepare cut hydrangea stems?

  Cut at an angle, remove any submerged leaves, and treat with boiling water or alum. Place in lukewarm water with flower food.

• What tricks help cut hydrangeas last longer?

  Dip stems in boiling water
  Use alum powder
  Mist the blooms
  Use glucose-based preservative
  Defoliate excess leaves

• Does hydrangea colour affect vase life?

  Not significantly, but white varieties are more delicate and require slightly more attention to avoid browning.

• Should I use cold or warm water in the vase?

  Use lukewarm water for best absorption and change every 1–2 days.

• Is flower food necessary?

  Yes. Choose one with glucose, acid, and a biocide for maximum freshness.

• Can I use hydrangea cuttings from my garden?

  Yes, but be sure to harvest them in the morning, use the same care steps, and avoid letting them dry out.

• How often should I change the vase water?

  Every 1–2 days. Clean water prevents bacterial growth and keeps stems absorbing effectively.