Why supermarket flowers droop in days at home and the florist’s copper coin trick that rescues them

Emily Turner • December 10, 2025 17:42

The plastic sleeve crackles as you slide the bargain bouquet onto the checkout belt, tucked between a bag of salad and a loaf of bread. Bright gerberas, tight roses, a cellophane promise that your kitchen table is about to look like a magazine spread – for £4.99.

You get them home, grab the nearest jug or pasta jar, snip the elastic and drop them in. For one glorious evening they look like they belong in a florist’s window. Then, almost overnight, the water clouds, the stems turn slimy, and the heads bend over as if they’ve given up on life.

By day three you’re fishing wilted petals out of your tea and muttering that supermarket flowers are a waste of money.

Then a florist friend casually mentions that she drops a copper coin into her vases to keep stems perky. It sounds like old‑fashioned superstition, the sort of tip your nan might have cut from a magazine in 1978 – until you see how long her bunches last.

So what’s actually happening to your flowers, and can a 1p really rescue them?

Why supermarket flowers flop so fast at home

Cut flowers are, bluntly, dying plants on borrowed time. The way they’re grown, shipped and sold decides how much of that time is left when you pick them up with your milk.

Most supermarket bouquets start life in huge farms in the Netherlands, Kenya, Colombia or further afield. They’re cut, bunched and chilled, then spend days in boxes, lorries and depots before they hit the bucket at your local Tesco or Aldi. Every hour in transit is an hour they’re not properly drinking.

In an ideal world, those stems would be trimmed, kept in deep, clean water with preservative, and rotated often. In reality, supermarket staff are juggling everything from rotisserie chickens to reduced stickers. Buckets run low, stems sit half‑out of the water, displays live under hot strip lighting and automatic doors blast warm air every few minutes.

By the time you take them home, many supermarket flowers are already dehydrated, stressed and several days older than a similar‑looking bunch from a dedicated florist.

At home, they go through another shock. They move from a chilly store into a centrally heated kitchen, straight into a vase that might not be scrub‑clean, filled from the tap. No conditioning, no preservative, no second thought.

The result is that the last few days of their life play out at double speed.

What’s going on inside a drooping stem

It helps to imagine each stem as a bundle of tiny drinking straws. Those straws – the xylem – pull water up from the vase into the flower’s head. Anything that blocks or damages them turns a perky bloom into a drooping one.

Three quiet things go wrong on that journey from field to table:

Air locks. When stems are cut and then left out of water, tiny air bubbles slip into those “straws”. Once an air bubble forms, water can’t travel past it easily. Florists routinely re‑cut stems under water to push those bubbles out. Supermarket flowers often never get that second cut.
Stem sealing. Every time a stem dries a little, the cut end can seal over with sap and microscopic debris. That’s like putting cling film over the top of each straw. You can’t see it, but your flowers can feel it.
Temperature whiplash. Flowers like cool, stable conditions. Going from a chilled depot to a warm shop floor to a hot car to a cosy living room in a few hours is the botanical equivalent of sprinting between saunas and ice baths. It speeds up ageing and wilting.

Florists build conditioning time into their routine. New stock is unpacked, stripped, re‑cut and left to drink in a cool back room before you ever see it on display. Supermarket bunches often skip most of that calm recovery period.

How your vase turns into a bacterial swamp in 48 hours

You probably blame the flowers when they droop, but your vase is often the real villain.

Every stem that goes into water sheds a little sap, sugar and plant tissue. Every hand that touches that vase adds a sprinkling of bacteria. Left alone, that mix turns the water cloudy, slimy and faintly swamp‑smelling. It also clogs up those “straws” inside the stems.

Bacteria multiply fastest when they have three things: food, warmth and time. A supermarket bouquet in a cosy kitchen, in water that hasn’t been changed for days, is basically an all‑you‑can‑eat buffet.

Flower food sachets – the little powder packets that come with better bouquets – are designed to tackle exactly this. They usually contain a mix of:

Sugar (to feed the flower, not the bacteria)
An acidifier (to keep the water slightly acidic, which slows bacterial growth)
A biocide (a mild antimicrobial to stop things going swampy)

If your bunch comes with a sachet and you chuck it in a drawer, you’ve just thrown away a big chunk of its lifespan.

Meanwhile, florists scrub their vases with proper detergent, change water daily and re‑cut stems every couple of days. Same flowers, completely different environment.

The copper coin trick: superstition or science?

Walk into many old‑school flower shops and you’ll spot it if you look closely: a dull penny or two sitting at the bottom of a glass vase, glinting under the stems.

The idea is simple. Copper has mild antimicrobial properties. A clean copper surface in water can:

Release tiny amounts of copper ions
Make the water slightly more acidic
Inhibit the growth of some bacteria and fungi

Less bacterial slime means clearer “drinking straws” inside the stem and, in theory, longer‑lasting, perkier blooms. That’s why copper pipes are popular in plumbing and why copper compounds turn up in some garden fungicides.

There are a few important catches, though:

Modern UK coins aren’t pure copper. Since 1992, 1p and 2p coins have been mostly steel with a thin copper plating. That’s still enough copper on the surface to have some antimicrobial effect, but it’s not a magic bullet.
The coin must be clean. A grimy, sticky coin straight from the bottom of your bag is mostly adding dirt and oils. A quick wash with soap, and even a wipe with vinegar, helps expose the copper surface.
It works with, not instead of, good care. A copper coin in a filthy vase of week‑old water won’t rescue anything. Think of it as a helpful extra, not a replacement for fresh water and a stem trim.

In practice, many florists who swear by the trick also do everything else right: clean vases, flower food, cool rooms, constant rotation. It can be hard to untangle how much credit the coin truly deserves.

Still, trials and household experiments tend to show a small but real benefit, especially for thirsty, floppy‑prone flowers like tulips and gerberas. The stems stay firmer, the water smells fresher, and you squeeze another day or two out of the bunch.

If you like a low‑effort, low‑risk hack, a couple of clean pennies at the bottom of the vase are worth a try.

How to actually use the coin trick – and make it work

If you want to give your supermarket bouquet a fighting chance, here’s how to combine the copper trick with florist‑style conditioning.

Prep the vase properly.
- Wash it with hot, soapy water and rinse well.
- Add lukewarm tap water (cool for spring bulbs like tulips and daffodils).
- Stir in flower food if you have it.
Clean your coins.
- Choose 1–2 modern 1p or 2p pieces.
- Wash in hot, soapy water, then rinse.
- For extra shine, rub briefly with a bit of vinegar or lemon juice, then rinse again.
Condition the stems.
- Remove the plastic sleeve and elastic.
- Strip any leaves that would sit below the waterline – they rot fast.
- With a sharp knife or scissors, cut 1–2 cm off each stem at an angle. Doing this under water (in a bowl or under a slow tap) helps avoid air bubbles, but even a quick, clean cut in air is better than nothing.
Add the coins and arrange.
- Drop the clean coins into the vase.
- Place the flowers in so that no leaves sit in the water.
- Move the vase to a cool spot, out of direct sun and away from radiators or fruit bowls.
Refresh regularly.
- Every other day, change the water completely and rinse the vase.
- Re‑cut the ends of the stems by a centimetre.
- Pop the coins back in once they’re rinsed.

Soyons honnêtes : nobody does this entire ritual perfectly every time, especially when you’ve just dashed in from work and the pasta’s boiling over. But even doing half of it – a clean vase, a quick trim, fresh water plus coins – makes a visible difference.

Steal a florist’s routine for supermarket flowers

Florists don’t have secret miracle powders you cannot buy. What they have is a boringly consistent routine.

You can copy the essentials at home with five small habits:

Cool first, display later.
Let fresh flowers drink in a cool hallway or spare room for a few hours before moving them to a warm kitchen or sunny windowsill.
Keep them away from fruit.
Ripening fruit, especially bananas and apples, gives off ethylene gas that speeds up ageing in flowers. Counter‑top fruit bowl next to your vase? Not helping.
Protect them from heat and draughts.
Avoid placing vases on top of radiators, next to ovens or in the direct path of open windows and doors.
Top up and trim, little and often.
A 10‑second stem trim and a quick water change every two days buys you more life than any dramatic rescue mission once they’re already floppy.
Downgrade them gently.
When a mixed bunch starts to fade, rescue any strong survivors (often carnations, chrysanthemums) into a smaller vase with fresh water and another coin. You can get a second, simpler arrangement for free.

Once you start treating flowers less like a one‑evening decoration and more like a living thing you’ve temporarily adopted, their lifespan quietly stretches.

Flower myths vs tricks that actually help

Here’s a quick guide to what’s worth your effort and what’s mostly folklore:

Trick / habit	Does it help?	Why it matters (or not)
Copper coin in vase	Sometimes, a bit	Mild antimicrobial effect, best with clean water
Flower food sachet	Yes, noticeably	Feeds bloom, controls bacteria and pH
Aspirin in water	Not reliably	Mixed evidence; not designed for cut flowers
Sugar alone	Can backfire	Feeds flowers and bacteria – water spoils fast
Tiny splash of bleach	Yes, if very diluted	Slows bacterial growth; ¼ tsp per litre is enough
Vodka or gin	Rarely worth it	May slow opening but can also stress the flower
Boiling water for woody stems	Sometimes useful	Helps open clogged stems (for roses, hydrangeas)

If you had to pick just three habits for a supermarket bunch: clean vase, regular stem trims, and some form of antimicrobial help (flower food, a tiny bit of bleach, or yes, a couple of clean copper coins).

Key habits at a glance

Re‑cut stems and strip underwater leaves as soon as you get home.
Use a genuinely clean vase and change the water every 1–2 days.
Keep flowers cool, away from fruit, radiators and harsh sunlight.
Add a little antimicrobial help – flower food, diluted bleach, or a copper coin.
Rescue still‑healthy stems into a smaller vase as the bunch ages.

Rethinking what a “cheap” bunch really costs

A £5 supermarket bouquet that droops in two days doesn’t feel cheap; it feels wasteful. Not just in money, but in mood. You bought those flowers to make your home feel softer, calmer, more alive – and instead you get guilt over the bin.

With a few florist‑style habits and a couple of clean copper coins, the maths changes. The same bunch stretches to a week or more of colour. The table looks inviting every time you walk past. You start to trust that buying flowers is a small kindness to your future self, not an indulgence that melts overnight.

You don’t need a fancy florist on speed dial to get there. You just need to stop treating supermarket flowers as disposable and start treating them, briefly, the way professionals do: as living things that will repay a tiny bit of care.

Point clé

Point clé	Détail	Intérêt pour le lecteur
Stress des fleurs de supermarché	Long transport, peu de conditionnement, chaleur	Comprendre pourquoi les bouquets “pas chers” fanent vite
Vase propre + entretien régulier	Eau changée souvent, tiges retaillées	Gagner plusieurs jours de fraîcheur sans effort extrême
Astuce de la pièce de cuivre	Légère action antibactérienne en complément	Un petit geste simple pour prolonger la vie des fleurs

FAQ:

Do UK copper coins still contain enough copper to work? Modern 1p and 2p pieces are copper‑plated steel, but the copper on the surface is what touches the water, so you still get some antimicrobial benefit.

Can the copper in the water harm pets if they drink from the vase? The amount of copper that leaches from a coin into a vase is very small, but it’s still better to keep pets from regularly drinking flower water, which can contain plant toxins and bacteria.

Why do florist bouquets last longer than supermarket ones? Florists usually buy fresher stock, re‑cut and condition it properly, use clean vases and preservatives, and keep arrangements in cooler conditions.

How long should supermarket flowers last with good care? Many mixed bouquets can last 5–7 days, sometimes longer for hardier stems, if you re‑cut, refresh the water and keep them cool.

Is flower food really necessary if I use a copper coin? A coin can help slow bacteria, but flower food also feeds the bloom and adjusts the water’s acidity. Together, plus good hygiene, they work better than either on their own.