Why Is Flower Food Important (And How to Make Your Own)

Every bouquet we send out includes a complimentary sachet of flower food. We also print flower food instructions on the care card that comes with each arrangement. We do this because flower food is one of the simplest things you can do to make your flowers last significantly longer, and most people either skip it or don't realise how much of a difference it makes.

Here's what flower food actually does, how to use it properly, and how to make your own at home when you run out.

What is flower food and what's actually in it?

Most people tear open the sachet and tip it into the vase without thinking much about it. But flower food isn't just one ingredient. It's a mix of three things, and each one serves a specific purpose.

Sugar. This is the food part. Cut flowers are separated from the plant that was feeding them, so they have no energy source. The sugar in flower food acts as a carbohydrate that the stems absorb through the water, giving the flowers fuel to continue opening, holding their colour, and staying firm. Without it, flowers use up their remaining energy reserves much faster.

Citric acid. This lowers the pH of the water, making it slightly acidic. Acidic water moves up the stem more efficiently than neutral or alkaline tap water because it reduces air bubbles that can block the tiny water channels inside the stem. Better water uptake means the flowers stay hydrated longer, the petals stay firm, and the blooms open more fully.

Biocide. This is a very small amount of antibacterial agent that slows the growth of bacteria in the vase water. Bacteria is the biggest enemy of cut flowers. It builds up in the water, clogs the stems, and causes that slimy film you sometimes see on stems that have been sitting for a few days. The biocide keeps the water cleaner for longer, which means the stems can keep drinking.

These three ingredients work together. The sugar feeds the flowers but also feeds bacteria, so the biocide is there to counteract that. The acid helps the flowers absorb the sugary water more effectively. Remove any one of the three and the others don't work as well on their own.

How to use the flower food sachet properly

This sounds straightforward but there are a few things people commonly get wrong.

Use the right amount of water. The sachet is designed for a specific volume of water, usually printed on the packet. Using too much water dilutes the food and the biocide, so neither works properly. Using too little concentrates the sugar, which can actually damage the stems. Check the packet and measure roughly.

Mix it into the water before adding the flowers. Stir the powder into the water and let it dissolve before you place the stems in. This ensures an even mix rather than having concentrated powder sitting at the bottom of the vase.

Change the water and add fresh flower food every two to three days. One sachet doesn't last the entire life of the flowers. The biocide is used up over time and bacteria starts building again. Fresh water with a new dose of flower food every few days makes a real difference. If you've used your only sachet, that's where the homemade recipe below comes in.

Common mistakes that shorten flower life

These are the things we see most often when customers tell us their flowers didn't last as long as expected.

Skipping the flower food entirely. This is the most common one. The sachet gets thrown away with the wrapping and the flowers go into plain water. They'll still last, but you're leaving days of extra life on the table.

Not trimming the stems before placing them in water. When flowers are out of water, even briefly during delivery, the cut end of the stem starts to seal over and air gets into the water channels. Trimming 2cm off each stem at an angle with sharp scissors or a knife reopens the channels so the flower can drink properly. This matters just as much as the flower food itself.

Leaving the flowers in the same water all week. Even with flower food, vase water deteriorates. Bacteria builds up, the food is consumed, and the water becomes less effective. If you notice the water starting to look cloudy or smell, it's well past time to change it.

Placing flowers in direct sunlight or near heat. Heat speeds up every process - the flowers open faster, the water warms up, bacteria multiplies quicker, and the flowers dehydrate. A bright spot with indirect light is ideal.

Leaving fallen leaves in the water. Any foliage that sits below the waterline rots and accelerates bacterial growth. When you first arrange your flowers, strip any leaves that would sit in the water. If leaves fall in over the following days, fish them out.

How the Sunshine Coast climate affects flower care

This is something we think about a lot because it directly impacts how long our customers' flowers last.

In the warmer months on the Sunshine Coast, particularly from October through to March, the heat and humidity mean bacteria builds up in vase water much faster than it would in a cooler climate. Flowers also dehydrate more quickly when the air is warm, and blooms open faster.

During summer, we'd recommend changing the water and adding fresh flower food every two days rather than three. Keeping the vase in an cool room makes a noticeable difference, and moving the arrangement away from windows that get afternoon sun will help as well.

In winter, flowers tend to last longer naturally because the cooler temperatures slow everything down. You'll often find that flowers up to three weeks in the cooler months with basic care. This is one of the reasons winter is actually a lovely time to have fresh flowers in the house - they stick around.

Homemade flower food recipe

When you've used your sachet and want to keep feeding your flowers, you can make a simple version at home with ingredients you probably already have.

Mix together:

• 1 litre of lukewarm water

• 1 tablespoon of sugar

• 2 tablespoons of lemon juice (bottled is fine)

• 1/4 tablespoon of household bleach

Why each ingredient matters:

The sugar provides the energy source, replacing what the commercial sachet's sugar does. The lemon juice acts as the acid, lowering the pH of the water so the stems absorb it more efficiently. The bleach is the biocide - a very small amount that keeps bacteria in check. It sounds alarming to put bleach near flowers, but at this concentration it's harmless to the stems and effective at keeping the water clean.

Use this mix each time you change the water. You can adjust the quantities proportionally if your vase holds more or less than a litre.

Why we include flower food with every order

We include flower food because we want your flowers to last as long as possible. Our customers regularly tell us their bouquets last up to two weeks with proper care, and some have reported up to three weeks. The combination of starting with the freshest seasonal flowers, including flower food, and providing care instructions with every order is a big part of why.

A couple of minutes every few days is all it takes to get the most out of your flowers.

Related reading

• How to Tell if Flowers Are Fresh: 7 Signs to Look For

• Florist vs Supermarket: Is There a Difference?