You are currently viewing Why Are Some Flowers Red?

By Linda Peacock, Master Gardener, SCMG

Continuing our celebration of “The Year of The Garden 2022” we have been studying many aspects of red flowers with a series of articles.   

It prompts an obvious question – why are some flowers red?   

Well, plants contain DNA just like humans do, the plant genes in their DNA tell the plant cells to produce water soluble chemicals called anthocyanins in their petals.  These chemicals are also present in other plants such as vegetables, you will have heard them referred to as their larger class name – flavonoids.  Anthocyanins are the flavonoids that can create red, pink, purple and blue colours.   To create red pigment in petals, the cells produce anthocyanins that absorb all colours of light except for red.  This allows them to reflect red light so that it appears red to us when we look at it.   It is through playing with these genes that flower producers have created the colours they want.  Plants with foliage that turns red in the fall produce more anthocyanins as they age to create this effect. 

Who likes red flowers? 

We like to have many colours in our gardens and red is a favourite to create an impact.   I have many reds in my garden – roses, petunias, poppies, monarda, geraniums, cardinal flower, etc.   

Red flowers on herbs tell us that the herb is stimulating not soothing like those with blue flowers. 

Why are pollinators attracted to them?     

Just like us, birds, insects, and butterflies see certain ways and certain colours are more obvious to them.  Vivid colours such as red stand out more to some as they cruise by looking for a snack.  The plants want to attract the pollinators that are the right shape and size to easily spread the pollen from one flower to another.  The plants have evolved to ensure they attract these pollinators to their flowers through colouring, smell, etc.   As the flowers fade to pink, it tells the pollinators that those flowers no longer need pollinating, and they have become less desirable as a food source.   

Which pollinators are attracted to red flowers?   

Hummingbird Moths are attracted to light red, pink, purple or white flowers that have a strong sweet smell at night.   

Butterflies like bright red or purple flowers with a faint fresh scent. 

Bird pollinators like flowers that are red and rich in nectar.  Locally, Hummingbirds are the prevalent bird pollinators and they prefer to feed at red, tubular shaped flowers that have no scent. 

Bees and wasps can see and visit red flowers. In the past it was believed that they do not see red and that was why the majority are more attracted to blue, yellow, and purple.  All bees and wasps like a sweet floral smell.   There are so many bee types that we need all colours in the garden to support as many as we can. 

Chipmunks, squirrels, mice, and birds other than Hummingbirds are also attracted to the red fruits and berries in our gardens that contain seeds.  They generally don’t pollinate the plants, but they do spread the seeds as they go about their day.  (We’ve all had those little rascals get the first tomatoes or berries before we do!)   

No matter what colour of plants you grow in your garden, a good mix creates a diversity that fills the needs of many throughout each season.  Adding native plants is important to provide a food source for our native bees, birds, butterflies, and insects.  The bigger the mix the better – the more creatures we attract and enjoy in the garden!   Why not include red to add some impact?