These seven different tricks on seven identical bouquets were tested to see which would be the most effective. Photo / iStock.
There's nothing more cheering than a bunch of fresh, colourful flowers brightening up your home. But while your bouquet may look beautiful at first, it often starts to wilt just days later - unless, that is, you have a secret ingredient up your sleeve.
The Duchess of Cornwall recently revealed her own trick to help cut flowers last longer - adding a few glugs of lemonade to the vase of water.
Others swear by tips such as adding aspirin, and the internet is teeming with ideas.
"The main thing that kills cut flowers is bacteria on the stems," explains florist Jennifer Stuart-Smith. "You can add all sorts of things to water to reduce it. But the key is finding something that also provides nutrients."
So do any of these secrets really work? And which is most effective?
Here is what happened using seven different tricks on seven identical bouquets (made up of two yellow roses, a pink hydrangea, a stock and garden foliage):
Ingredient: Mouthwash - one capful per litre of water.
The science: "Mouthwash is antibacterial, so it kills bacteria on flower stems in the same way it kills plaque in the mouth," says Jennifer. "But it contains artificial sweetener, rather than sugar, so it may not give the flowers the perk they need."
What happened: The mouthwash gives the water a strange, blue tint, while the minty aroma overpowers any floral fragrance. But for the first few days, the bouquet looks lively, with straight stems, healthy foliage and vibrant petals.
By day three, there are still no bubbles on the stems - proving an absence of bacteria - but the stock is starting to droop. This wilts by day five, and the hydrangea has started to shrivel.
The water has turned murky, too, suggesting the presence of bacteria. By day seven, only the inner rose petals and greenery are thriving.
Verdict: Four days of vivid colour and the longest-lasting roses of the lot. "Try mint-free mouthwash to avoid that pungent smell," says Jennifer.
Ingredient: Shiny 10 cent coin at the bottom of the vase.
The science: The copper in the coin is said to act as a natural antibacterial agent, stopping bacteria from forming on the stems.
In the experiment a British penny was used, but, since 1992, UK pennies have been made using copper-plated steel, not bronze, which doesn't have as strong an effect. New Zealand's 10c coin is also copper-plated steel. "I suspect this one may not work very well," says Jennifer.
What happened: Adding a tiny coin to such a tall vase and expecting it to work seems silly. Within a day, the stocks are nodding and the roses opening. They last three days looking bright.
However, by day four, the rose petals and the stock are drooping and the hydrangea isn't happy. By day six, the roses and stock have dried up.
Oddly, the hydrangea seems to gain a new lease of life and, by day seven, this is the only flower still standing. The water remains remarkably clear, though the stems have grown fuzzy with bacteria.
Verdict: Apart from the hydrangea, all were dead after four days. "The effect of the [coin] will have been negligible, providing no nutrients," says Jennifer. "The hydrangea may simply have been a robust one."
Ingredient: 125ml of clear, fizzy lemonade per litre of water.
The science: Known by florists as the 7-Up formula, this is the Duchess of Cornwall's horticultural secret. "Lemonade has two acids (citric from the lemons and carbonic from the bubbles), both of which are antibacterial and help the stems take up water," says Jennifer.
"Make sure it's not sugar-free, as sugar provides valuable nutrients."
What happened: The lemonade gives the water an appealing sparkle, and everything looks very perky and fresh until day two.
Then, the stock starts to wilt and the rose petals blacken around the edges. On day four, I notice an unpleasant stench, like rotting fruit.
All the blooms wilt, but worst is the hydrangea, which has lost its colour by day five. On day six, the roses flop, the stock sags and the leaves fall off.
Verdict: Sadly, I think Camilla's got it wrong: her method is the only one I tried where the flowers were dying by day two. This fizz is royally rubbish at keeping flowers alive.
"While sugar is needed for nutrients, it also helps bacteria grow," says Jennifer. "The acid in lemonade isn't strong enough to counteract this."
Ingredient: A sachet of powdered flower food (comes free with most supermarket flowers).
The science: Contains an acid to help the stems drink water, sugar to nourish and a biocide to kill bacteria that feed on the sap which seeps from cut flower stems.
"The only drawback here may be the concentration," says Jennifer. "If you use too much water, a tiny sachet will be very diluted."
What happened: This keeps the flowers healthy and the water clear for three days.
Wilting starts on day four when the roses open and one even turns brown around the edges. The other stems appear quite dry and crisp.
By day five, the stock is bowing and the leaves hang limp around the vase. By day seven, the whole lot is ready for the bin, including the hydrangea, which has lost almost all of its fuchsia pink hue.
Verdict: A big disappointment. I expected this professional food to be the best, but it only gave me three good days.
"You should fill a vase to an inch or two from the top," says Jennifer. "So one this big would need two sachets to provide enough nutrients."
Ingredient: A teaspoon of vodka per litre of water. Repeat every three days to maintain concentration.
The science: Alcohol is a known antibacterial agent, so it should kill bacteria on the stems.
"There is also some research, published in the journal Scientific American in 2007, that it stops the production of ethylene - a gas emitted by plants that helps them to mature," says Jennifer.
"So inhibiting this gas could slow the wilting process."
What happened: The stems start off perky and bright, but the roses open very quickly and, by day two, they are in full bloom.
The rest of the flowers look healthy, and there is no sign of bacteria, with the water remaining clear. On day four, when I add more vodka, the pink hydrangea brightens.
By now, the stock has wilted - usually, I'd have just removed it, because the rest of the bouquet has plenty of life in it.
By day seven, it's clear this is the healthiest bunch, with lush foliage and some still-bright flowers.
Verdict: The perfect way to use up the dregs of your drinks cabinet, vodka kept the flowers looking good for six days. "Some of these flowers would even last another few days," says Jennifer.
Ingredient: One crushed aspirin, dissolved in the water, per litre.
The science: "Aspirin contains the naturally-occurring salicylic acid, which discourages bacteria and helps the flow of water through the flower," says Jennifer.
"But the acid in aspirin is weak - something stronger would do a better job of turning the water acidic and helping the bunch thrive."
What happened: The hardest part is getting the aspirin to dissolve.
You're meant to use normal (not dispersible) aspirin, as this has a slightly higher salicylic concentration. I crush two with a spoon and add them to the water, stirring frantically to make them disappear.
But, by day two, they're still settling on the bottom. As a result, the flowers don't see much benefit. On day three, I spot slimy sludge growing on the stems, indicating that bacteria has settled in.
Both of the roses open and shrivel on day four and, by day five, the stock is bent and the leaves droop. Even the robust hydrangea has yellowed and withered by day seven, and the water has turned unappealingly cloudy.
Verdict: Not strong enough. "A more powerful acid, such as bleach or lemon juice, may be more effective," says Jennifer. "Also, there's no sugar in aspirin to feed the plant."
Ingredient: ¼ tsp of bleach per litre of water. Repeat every three days to maintain the concentration.
The science: It seems wrong to put delicate, fresh flowers in a vase with germ-killing bleach, but this tiny amount is diluted by the water.
"As long as it's not too strong, bleach will kill bacteria on the stems," says Jennifer. "It will also sterilise the water and stop it going cloudy. But it contains no sugar, so it lacks a nutrient source."
What happened: True enough, the water is clear and slime-free - and stays that way for seven days. Immersed in the intense bleach, though, the flowers seem to get a shock and, on day one, look the least healthy of the group.
By day two, they perk up: the stock stands straight, the hydrangea opens fully and the roses are a sunny yellow. The flowers continue to flourish, though the hydrangea discolours slightly, turning a pinky-orange.
By day five, it's looking worse for wear, although the leaves have stayed a healthy green and the stock has retained its deep purple.
Verdict: It seems unorthodox, but bleach really did the trick in keeping my blooms looking good for four whole days.
"Just make sure you keep it out of reach of children and don't put your hand in the vase," says Jennifer.
- Daily Mail
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